Bought a parts car, swapping my drivetrain.

[Turbo510]

Very interesting photo-project, and nice photography. Hopefully any fabrication to fit the B6 A4 parts to the Cabriolet chassis will be minimal.

[ImRobBailey]

Very interesting photo-project, and nice photography. Hopefully any fabrication to fit the B6 A4 parts to the Cabriolet chassis will be minimal.

Thanks! It's been quite an adventure so far, but nothing insurmountable.

From my research, the chassis is basically the same between B6 versions, and not much fabrication is required except for attaching supports for the driveshaft center bearing in the tunnel. Doesn't look too difficult, to be honest.

[neo0211]

I just finished my chassis FWD to AWD.
There are hardly any modifications and there won't be too many problems.
It's just that there are more things to install.
Come on ~ finish it.

[ImRobBailey]

I just finished my chassis FWD to AWD.
There are hardly any modifications and there won't be too many problems.
It's just that there are more things to install.
Come on ~ finish it.

Neo, I've been watching your build, too - super inspiring. I'm working on finishing this one - it's just taking a bit longer than expected with life getting in the way; fortunately I'm not taking any more classes over the summer, so I'll have more time to work on this project! I'm certain it would take less time working in a nice clean shop with a lift, but I'm not one to complain. Hopefully with another month or two of work, I'll get this whole thing buttoned up!

[ImRobBailey]

Delays delays delays...at least this time they were enjoyable: vacation & traveling.

Work has started for real this time. The blue convertible has been up on stands in the carport for just over a week now, and so far most of the under-trim has come off and been bagged and tagged. I don't know how much of the heat shielding and plastic aero trim will fit back on with the new setup, so everything is staying nice and organized for now.

Front drivetunnel bracing:


Rear drivetunnel bracing:


You can't see them in the picture, but I guarantee you they're there: ants. A whole colony of ants living behind the passenger side front mudflap. The dust and dirt near the ratcheting head of that wrench is all ants and colony material:


Once all the trim and drivetunnel bracing is removed, the exhaust is ready to be extracted. The fwd exhaust rear of the frontpipe is all one welded section: a central muffler/resonator, then two mufflers before the tips, all in one piece. It's a heavy unit that I covered with a tarp and stood up next to the house. I was too exhausted to take pictures of this part. (I know, I know - terrible joke).

Next I moved on to the rear subframe, brakes and brake rotors. I didn't trust the calipers and rotors from the yellow donor car, so I swapped the cabriolet's calipers and rotors from the fwd subframe to the awd. It's a little weird that these rotors don't have a set screw in them. They're not pretty, but they'll do the job.


One thing I noticed while installing the new pads is that the pads don't fit in their slots when I use the new abutment clips. When I removed the old brake pads, I didn't find any abutment clips, so it appears they weren't installed last time. That would explain the dragging I heard at slow speeds. So I'll remove the caliper brackets, clean them up, and reinstall them with abutment clips greased and tidy.

FWD subframe is out! It is ALOT lighter than the awd subframe, mostly due to the lack of axles and rear differential:




AWD subframe (and magic pumpkin):




I have the rear springs from the donor car, but I'll be using the stock rear springs that came with the cabriolet. After a fair amount of research and discussion, I've come to the conclusion that the cabriolet rear springs are stiffer than rear springs for the sedans. Also, this maintains a matched set of springs & shocks "so the spring rates are matched to the shocks yada yada yada." I'll add what I can to the spring color codes document as well.

A couple things I haven't quite figured out yet:
- Do I need to purchase an entire new exhaust? I thought I could get away with just a new frontpipe, but the more time I'm spending under the cabriolet, the more I'm convinced I'll need new piping to accommodate a driveshaft.
- The awd subframe has a levelling sensor on it, but the fwd subframe didn't - I wonder if it's even worth trying to tie in the sensor.
- The transmission and rear differential: do they require different types of gear oil? Part numbers are different, but it seemed to me that was due to different volumes of fluid, not fluid type. Old Guy has responded, and recommends Motul Gear 300 in the rear diff and Redline in the transmission. To my understanding, both oils are just 75w90 variable weight gear oils, and the majority of benefits are realized at extreme temperatures, especially cold starts, etc. Use-case for this car is Florida/SE-US.

Lastly, I really don't want to take apart the interior, but I know I need to. At least center console, and some bolster panels in the rear seat.

[ImRobBailey]

It's been a while since my last post, for reasons, but I've been working steadily on nights and weekends to button this project up ideally by the end of this month. Pretty tight timeframe, but convertible weather is here and I'd like to enjoy it in a convertible rowing through the gears.

The quattro fuel tank is installed and wired, but the secondary level sensor still needs to be wired to the cluster. That will likely be delayed until "stage 2" of this swap, as finishing is a priority. Also, the fuel system works, and the engine is confirmed running with the new fuel tank!

The rear subframe is fully installed, but I still need to add gear oil to the diff. I'm planning on adding all of my fluids in one go so nothing gets overlooked. This part was fun, and like playing with lego. The most terrifying part was compressing the springs to get them seated in their perches; I'm glad I had spring compressors, but still a terrifying process. Some sources I'd read mention that it may be possible to loosen the subframe mounting bolts, insert the spring, and raise the subframe back to the vehicle using a jack. In my experience, this began lifting the vehicle off its stands before compressing the springs far enough to seat on their perches. I still need to install the new subframe mounting bolts and tighten them to their final torque specs, torque the axle shoulder bolts to their final torque, and the lower strut mounting bolt an additional 90°.

There are a BUNCH of underbody panels and heat-shielding running down the drivetunnel that need to be removed, and then to the front. At this point I've already removed the rear section of exhaust from the central resonator to the rear twin resonators, but the cat and downpipe were still attached, preventing me from accessing the starter bolts. So I removed the intake box, and removed the o2 sensor upstream of the cat, unbolted the cat, and realized there's another o2 sensor downstream of the cat. So I rented an o2 sensor removal socket kit, removed the sensor, and pulled the cat and downpipe from the car. Now the starter bolts were exposed, and I could start loosening them to get a look at the flywheel flexplate driveplate torque converter whatever you want to call it situation (see this post for reference).

Before I removed the cat, I had begun removing all of the ATF cooling lines, filters, and brackets. Getting these components out of the way was instrumental to freeing both axles from their homes and in removing the cat and downpipe from where they were wedged next to the transmission.

I'm ordering parts this weekend so hopefully they'll be here next weekend and installation can begin!

[ImRobBailey]

The CVT is out! A friend stopped by yesterday and lent a hand prying the trans off the engine, then helped me safely raise the front end of the car tall enough to slide the trans out...eventually. (read: tomorrow)

An interesting array of bellhousing bolts; many more than were holding the 01A trans in the yellow car:

CVT bellhousing bolts:


Ready to pop!


Lying on the ground:

[ImRobBailey]

New clutch line is handled, but it looks like I need clutch line retaining clips. Anyone know where to source these? I don't have an example to match, since I was a bozo and didn't keep track of them when I took them off the old car.

I know Old Guy has addressed this in the past and said some fastener shops may have a similar clip, but without a clip to match, starting from a vacuum seems nigh impossible.

Does anyone know the part number, or where to get them? I think I found an equivalent VW part, but no guarantees of fitment...

[A4SoftWalker]

This is a nice project. I will eventually borrow from it as my rear subframe is rusty and the sway bar mounts snapped off due to rust and stiff Hotchkiss sway bar on too soft of a spring.
What are you going to do about your radiator cooling system for your transmission? Loop it back on itself to close it off or just plug both ends?

[ImRobBailey]

What are you going to do about your radiator cooling system for your transmission? Loop it back on itself to close it off or just plug both ends?

Thank you! It's my first "big" project, and while it's taken longer than expected initially, I've learned a lot and have gotten a ton of enjoyment out of the whole process.

To be perfectly honest, I just wasn't going to do anything about it - there shouldn't be any fluid left in there, and while weighing the benefits of plugging the holes vs leaving them, plugging the holes only provides backwards compatibility if I ever want to reverse the swap.

Granted, I haven't looked into it in any depth at all, really. I assumed the ATF fluid pump was in the trans, so I could just remove the lines and leave a couple unused holes in the radiator. Can you see any advantages to plugging the lines vs leaving them open?

[A4SoftWalker]

I would plug them - but thats just me... It would bother me knowing I had those openings vented to atmosphere...

You could also want to run something else in there in future like... oh... I dont know... an external oil cooler loop for your motor if you go big turbo in the future... hint-hint.

That would be a first. I dont think I have seen any of us do that yet. Just remember to throw on a thermostat sandwich adaptor not just a regular adaptor and you will have a clean install.

Best of luck with your build and mods

[ImRobBailey]

I would plug them - but thats just me... It would bother me knowing I had those openings vented to atmosphere...

You could also want to run something else in there in future like... oh... I dont know... an external oil cooler loop for your motor if you go big turbo in the future... hint-hint.

That would be a first. I dont think I have seen any of us do that yet. Just remember to throw on a thermostat sandwich adaptor not just a regular adaptor and you will have a clean install.

Best of luck with your build and mods

Well these are some ideas I hadn't considered yet...

Saving this for the future, and now I'm looking for some plugs for those holes!

[kwilson]

I once used an Auto radiator in a MT Passat because it was half the price. I just left the holes open, and everything was fine.

[Dr.B6Banter]

Yes, there is no coolant flowing through the trans cooler section of the rad (assuming the radiator is in good shape lol) so it's fine to leave it open. Plugging it just protects the insides in case you want to go back to the auto which I can't imagine you'd want to do lol

[ImRobBailey]

Things are installing and progress is going quickly!

While there was no transmission in the tunnel, I fed a piece of sturdy but flexible wire up through a hole in the bottom of the battery/brake booster tray, and ended up actually bullseyeing it straight into the cabin behind the pedals where I wanted it. Then I taped my new stainless steel braided clutch line to the wire, and gently pulled from the end under the car. Boom. Way simpler to route the braided line than I expected. I 100% expected to be removing the brake booster and be trying to thread the cable through uncooperative holes. Not the case for me, YMMV.

A new clutch (the "Perfection clutch single mass flywheel conversion kit" from RockAuto) fit up to the back of the cvt engine with no issues; pressing in the pilot bearing took some effort, as expected, but encountered no real issues. A 16mm 3/8" socket is just about the right size to press in the bearing.

Back of the crank pre-pilot bearing:


I was really conscientious not to over-lubricate any surfaces, even removing grease where I thought I'd added too much or the wrong type to the input shaft splines. Then I thought I was being REALLY clever: I poked a hole in the center of the plastic covering the friction disc so I could pass it over the input shaft and lube it up with the provided grease. Of course, I was so proud of my method of only partially unwrapping the friction disc to lube the center that I was not intentional to make sure the friction disc is installed in the correct orientation. Thinking back to installing it, I can remember unwrapping the rest of the plastic, and I *think* I checked the orientation, but I'm not 100% certain. Damnit. Looks like the transmission will be coming off so I can recheck the friction disc orientation. Oh, I also found this metal gasket that blocks off a void around the starter that should probably be installed as well. One step forward, three steps backward. Hope I get there eventually!

Clutch fitted, looking good:


Gratuitous clutch image:


I really wish it were possible to tell if the friction disc is installed in the proper orientation from here, but I doubt it:


Whoops, this might be important.


I got the new pedal group installed, too. This was kind of a pain in the neck, back, fingers, crack, you name it, it hurt. Mostly because the process involves taking the clutch pedal off the group (otherwise the whole unit doesn't fit over the steering column), offering up the pedal bracket and loosely fixing it into place. At this step, I got the brake pedal threaded onto the push rod a little ways, then threaded a little of the allen bolt holding the bracket to the dash, then move to the brake booster side. The two 10mm 12 point bolts going through the brake booster actually thread into the back of the pedal bracket. I found the best way to line them up was to leave the pedal bracket loose, then manipulate the brake booster until a couple threads catch on each bolt. Then move into the cabin again and feed the clutch master cylinder feed line through the firewall and clip into the top of the pedal bracket. Reattach the clutch pedal to its pivot (note: there is a set screw in the middle of this pivot assembly. If this set screw is loose, the whole pivot assembly may push out the opposite side of the pedal bracket when attempting to reattach clutch pedal.) There are two bushings, one on the inside of the pivot that must be applied before attaching the clutch pedal, a bushing that is applied after attaching the clutch pedal, then a thin washer (in my case it was split, possibly due to age; else it's the cap off the outer bushing which has separated with age), and then the final clip. Attach the master cylinder to the pedal bracket (this will also push the clutch hydraulic line through the firewall) with two 13mm bolts, then fully torque down the brake booster bolts, then fully thread the brake pedal to the push rod. Final adjustment will come later. Now start torqueing down the bolts going through the brake booster. Attach pedal switches (in my case I only have a brake switch because I broke my clutch switches removing them from the donor car; these will be added in phase 2), and unfold yourself from beneath the steering wheel!

Boom; manual pedals. Starting to look more like a manual transmission car! Please excuse the mess underneath the pedals. Also, if anyone knows what that small plastic cap goes to, I'm super interested; I know one of those clips functions as a position indexer for the pedal bracket, but that one is installed! This cap could be an extra because I have two pedal groups. Not sure. That said, if anyone needs an automatic transmission pedal group, let me know!


I started installing the shifter group, selector and push rods, but have messed up their attachment points - either to the transmission or to the shifter group. I'll have to reassess this part after a little more research.
Here's what I've got so far:


Shifter box is pretty close to the correct location, but something is seriously off about the mounting of the selector and push rod - they're close, but misaligned; you can see the push rod bushing is not happy with its position, and positioning the 8mm hex bolt to thread into the transmission was a pain. My suspicion is that I've attached the push rod to the top connection of the shifter group and the selector rod to the bottom connection and they need to be reversed. Not 100% certain, but it's my best guess at this point.

Is this where this goes? (you can see the bushing looks angry here)


Transmission installed with crossmember support:


You know what bolts are really hard to tighten? The lower bellhousing bolts which are mostly hidden by the subframe. One thing I've learned since this picture is that if the sway bar is lowered out of the way, there is more room to tighten those bolts using an extension from the front. Also notice the lower bellhousing bolt farthest to the right in this picture is threaded into the bolt hole that was welded back on earlier this year. Surprisingly, the bolt actually threaded in completely! I'm not sure if I'll torque that one down to spec; I may sneak up on the spec and incrementally torque tighter to see how much pressure the seam will take.


I also need to find a pinout for the TCU connector so I can splice in connections from the newly installed transmission.


Lots of progress, getting exciting!

[A4SoftWalker]

Lots of good progress here. I dont think you installed your clutch friction disk backwards. I was playing with mine last week and it physically will not bolt together backwards... My results might be different though I have a "Spec" brand clutch.

Your gear shift push rod hex 8mm bolt is 30lb-ft and that is where it goes. You are correct.
The selector rod 10mm bolt is 17lb-ft I would use blue loctite on this bolt. It is actually a one-time use item. It would be a special order part. I have not seen it for sale anywhere. I didnt look too hard, the loctite works fine.

[ImRobBailey]

Lots of good progress here. I dont think you installed your clutch friction disk backwards. I was playing with mine last week and it physically will not bolt together backwards... My results might be different though I have a "Spec" brand clutch.

Your gear shift push rod hex 8mm bolt is 30lb-ft and that is where it goes. You are correct.
The selector rod 10mm bolt is 17lb-ft I would use blue loctite on this bolt. It is actually a one-time use item. It would be a special order part. I have not seen it for sale anywhere. I didnt look too hard, the loctite works fine.

Thanks Jo - that makes me relax a little bit. I looked at the old clutch & flywheel I took from the donor car, and they didn't look like they would fit in the wrong orientation either. Of course, that looked like the oem dual-mass flywheel, and I don't know if there's a big difference between single-mass and dual-mass friction discs. Encouraging nonetheless - thank you!

I noticed that the selector rod bolt is indicated as a "one-use" item. I think I'll probably just blue loctite it just like you did. For now I've just stuck it on there loosely while I get everything else sorted.

Next up I'm going to loosen the transmission and slide this sucker in place because it looks important:


I guess I should do that before completely sorting out the shifter situation...

I also need to order fluids.

Hopefully I'm on track to finish phase 1 by the end of the month!

[ImRobBailey]

So I've done a bit more investigating and messing around under the car, and I'm still not convinced I have the push rod in the right place. Perhaps I'm crazy, or more likely I'm missing something that's making this not fit.

Going through some diagnostic thought: IF I have the push rod mounting point on the transmission correct, and if i have the shifter push rod mounting point correct, then it feels like I have the wrong push rod. It's almost like it's an inch or two shorter than it needs to be, which winds up putting the shifter almost into the climate control.

Here's a picture where it doesn't look too bad:


But take a look here where you can see that all of the shifter adjustment is as far forward as possible, and I'm unable to adjust the push rod connection to the shifter:


This is the front of the shifter group; under the blue colored metal in front of the threaded stud is the push rod adjustment - shouldn't this be exposed? For, you know, adjustment?


Next is the push rod to transmission mounting point. In this picture it is clearly connected at a bias, and not parallel with the mating surfaces:


Is there any reason I couldn't move the push rod mounting point backward one spot? It appears there is another threaded hole that will accept the push rod mounting bolt...
I'll reference some diagrams:



And comparing those to what I've got going on...


I'm still not sure. I'll move the push rod back one spot, see if that fits nicely and report back.

[ImRobBailey]

Whelp...looks like I just mounted it up wrong the first time. Everything fits like butter now.

Shifter group (now adjustable):


Test fit of the custom shift boot I made:

[A4SoftWalker]

Glad you got your push rod straightened out.. according to your diagrams they were in the correct position.Too late to help you now but I recently swapped transmissions. It made things easier to pre-fill the transmission gear oil before installing in the car.

[ImRobBailey]

Glad you got your push rod straightened out.. according to your diagrams they were in the correct position.Too late to help you now but I recently swapped transmissions. It made things easier to pre-fill the transmission gear oil before installing in the car.

Thanks for confirming that - I had the same thought about the diagrams. Hopefully this helps someone in the future.

I am now realizing that I probably should have filled the transmission before installing it like you say; I'm hoping once I level the car out there will be enough room to fill the transmission...and the rear diff...I probably should have filled both of those before installing them...

[Dr.B6Banter]

Great progress and as someone that went through this process I know the pictures will be very helpful for future DIYers!

A couple of notes. Like others have stated the friction disk isn't symmetrical and has a raised section on one end where the springs go which fits into the flywheel side I believe so I don't think it would even fit up the other way. Also with the pedal bracket, I just undid the bolts that connect the steering column to the rack allowing me to move it out of the way and fit up the manual pedal box without any disassembly. May save you some time next time you're down there.

Plenty of room to fill both the trans and the rear diff in the car with a fluid pump.

[ImRobBailey]

Well this weekend felt pretty productive, if frustratingly tedious.

When we initially installed the transmission, I had misplaced this metal gasket/facing that separates the transmission & the engine:


Finding it later in the trunk, I realized it's vital to preventing foreign matter from entering the transmission from around the starter, so it had to go back in. First I supported the transmission with a jack and backed all of the bellhousing bolts out ~1/2", and then started levering the transmission off the engine - just far enough that the bellhousing would clear the dowels on the engine side, and this gasket could be fed through. At this point, I checked the upper bellhousing bolts to ensure they weren't supporting the weight of the transmission, and started removing them...all the way from under the starter on one side to the dowel on the opposite side. All of the bolts spun out with my fingers, and the transmission didn't shift. Fortunately the gasket is pretty flexible, and flexed as I fed it into the crease; otherwise, I would have needed to remove the transmission, install the gasket, then reinstall the transmission.

Once the gasket was seating and the upper bellhousing bolts sorted, I started working on the lower bellhousing bolts. A combination of jacking up the transmission and sheer determination helped this process along. When I say tedious, I mean 1 ratchet click at a time, reset, then 1 ratchet click. An offset spanner is probably the way to go here, but I didn't have one. Also, I'm pretty sure I used some #CrossThreadingIsJustFreeLoctite on one of the lower bolts. At this point though, I'm almost in "fuck it, just send it" mode - the car has been on stands in the carport since July, and I'm ready to have it down and drivable!



one click at a time:




getting closer:




3-4 clicks per turn!


So once I threaded the lower bellhousing bolts in all the way, I installed the starter. This was quite a bit easier to access with the manual transmission installed than with the CVT, although the bolting procedures differ. The bolts for the starter on the CVT secured from both the front and back of the transmission - the upper bolt threading into the starter and seating the head against the transmission while the lower bolt threaded into the transmission, seating the head against the starter. Now both bolts thread into the starter and seat against the transmission. I hope this doesn't make too much of a difference.

Next I'm looking into mobile welders; I don't have the experience or tools to weld the driveshaft center bearing brackets to the belly of the car, and it will likely be easier and faster to hire a professional to do the job than try to fumblefuck my way around learning a new skill on my back underneath a car. Looks like it'll be ~$200ish to get the brackets welded on. :(

[A4SoftWalker]

Good update:

Your efforts to get those bottom 4 bolts in seem so laborious. I dont remember if you mentioned using an engine support bar? Did you use the engine support bar to lift up the motor from under the hood? This creates extra space for those tough-to-reach bottom tranny bolts.

Also it seems like you are using a ton of energy to tighten those bolts I only used a shorty 16mm finger ratchet wrench like you had to snug up the bolt and then tighten the last few turns to 33ft-lb with a 90-deg offset wrench.

Im sure you know but those bottom 4 bolts go into your oil-pan. That is why I always remove them First and install them Last.

Also I leave the transmission jack or whatever you are using to support it on there until all the bolts are in; including the transmission cross-member and tranny mount to some extent. I usually move the jack around to help me settle the tranny mount.

Hopefully, you don't have any strippers going on in there on your 16mm oil-pan bolts? Lol at

#CrossThreadingIsJustFreeLoctite.

Did you get the big 18mm bolts that go into the engine block in first?

Fingers crossed for you.

[ImRobBailey]

Well, I confess that in the midst of frustration and the desire to persevere, poor decisions have likely been made.

Key mistakes so far: not using an engine support bar from above as recommended. I bet that would make this tons easier to maneuver tools around and actually access the bolt heads. I'll put it on the list to buy before doing anything like this ever again. Because I don't have an engine support bar, I haven't loosened the front of the subframe (because it appears to support the engine mounts). This means access is incredibly tight. Here's another mark for doing it the right way, instead of the "easy way." In this case, I opted for the "easy way" of not purchasing and installing an engine support bar and...well as you can see it's cost me a stripped bolt and made my labor much more difficult (I imagine).

I did have the sense to fully support the weight of the transmission at all times so it wasn't ever just hanging off the input shaft.

Fortunately, these lower bolts appear to actually thread into the lower transmission housing, with the head mating against the engine, so hopefully I've only buggered one bolt hole in the transmission rather than the engine.

In this vehicle, all of the bellhousing bolts have all been 16mm with varying length shafts. There are several bolts on the driver's side that require longer bolts than were in with the CVT, and as I mentioned before, the orientation of the lower starter bolt is now reversed.

This has been quite the learning experience so far, and I'm certainly only scratching the surface of future endeavors. That said, several things have been made exceedingly clear: 1-right tool for the right job or you'll bugger something. 2-"cheap" is relative. 3-having a manual is key.

[A4SoftWalker]

You are right the bolts go into your tranny with one of them on the driver's side being bolted on with an actual nut. The one time I stripped my rear coolant flange bolt I had the same mindset.

Rushing
Getting impatient
Car sitting too long
Not looking at steps in instructions I just downloaded to my phone the day before
Telling my self to man-up and wrench it in there
Well the poor 6mm bolt took out the threads in a nice neat slinky-coil.

Took me 3 hrs of wrenching "blind" behind the cylinder head, hours spent researching thread replacement kit options, and days more waiting for Amazon to deliver 4-days late to get back on track 6-days later.

I dont think you have any show-stoppers there. Just keep these in mind in case anything acts up in the future related to this area you've been working on. It is possible to re-thread the transmission - I think or just source a spare for later. I think your reverse light and clutch master/slave setup along with your driveshaft welding are your most challenging pieces of the puzzle remaining.

Hang in there.

Wrenching on Audis is like "Dancing With the Stars" - choreographed down to the smallest step.

[ImRobBailey]

You are singing my tune down to the note. I'll be more careful from here forward, but for now I think this one is going to be snugged down and left for now. If (hopefully not when) I need to drop the transmission again, I'll address it then.

I'm curious though - how did you end up replacing the threads?

[A4SoftWalker]

You are singing my tune down to the note. I'll be more careful from here forward, but for now I think this one is going to be snugged down and left for now. If (hopefully not when) I need to drop the transmission again, I'll address it then.

I'm curious though - how did you end up replacing the threads?

Look up TimeSert. Keep that name in your back pocket - A beautiful Made in the USA company.

[ImRobBailey]

Look up TimeSert. Keep that name in your back pocket.

I'll definitely keep that for when I next pull the transmission. I was wondering if there was a "nutsert" equivalent for bolt holes. These look fantastic, and I'll likely end up using some!

Today's been a big day. Holy crap. First start on the new transmission. Damn did it feel good to hear it come alive and sound just fine! Link for sound, proof, & happy dance: https://www.instagram.com/tv/CVlAsiV..._web_copy_link

Was that enough though? I think not! Following the many swaps who came before me, I located, pulled, and jumped the appropriate terminals on the neutral parking safety switch; this is a temporary solution while I shop for another clutch switch to wire in. I like the safety of needing to press the clutch to start the car, and while I have the required switch, I was apparently not careful enough when removing it from the donor car, damaging it irreparably. Regardless, the switch is a cheap part, I've saved the relay I removed, and will eventually add a proper clutch switch instead of just a jumper.

I feel like I'm coming very close to the end of a long and exhilarating experience. The clutch is plumbed, and hydraulic line secured (one end with an oem clip, and the other with a custom fabricated [i.e. bent with pliers] clip).

I'd like to wire up reverse lights, but I'm having a hard time finding the appropriate diagrams to tie into the cvt harness - first, there's this huge connector - do I even do anything with that or just tie it out of the way?


Then I have four wires coming from the transmission. Unfortunately I can't find any wiring diagrams for this transmission in particular, although I would guess one set is for the reverse lights and the other set is for...vehicle speed sensor? Ideally I could just wire right into the old cvt harness, but I'm having trouble finding diagrams for that connector's pinout.

The search continues.

[Mike Tries]

I ripped the threads out of my first cylinder head's spark plug hole. I used something like a TimeSERT, but cheaper. I highly recommend getting an ACTUAL TimeSERT kit like A4Softwalker recommended. The end result is going to be better, and likely more permanent. The kits might be a little expensive, but you get more than one use out of them I think.

[Kevin C]

Helicoil or a timesert. Personnel preference is helicoil. Both work and are stronger than the original threads.

[ImRobBailey]

The brakes are now bled, as is the clutch - only took about a liter of fluid, so I have some to return. I filled the transmission with fluid, and tried to start the car...but the battery failed before it could come alive. So I hooked some jumper cables to my wife's car, and tried again...to no avail.

Okay, back to basics: spark, fuel, air. Haven't touched the ignition system, and the airbox was assembled correctly...but the fuel system - I did replace the fuel tank (and then made sure it would run afterward), and now it no longer runs...hmmmmm. When I turn the key, do I hear the fuel pump prime? Well, I hear the fuel pump relay click, but I don't hear the pump pressurizing the system like I would expect. So I opened the fuel pump access port, and attached a fuel line to the pump outlet, the other end draining into a mason jar. With a turn of the key, the fuel pump pushes fuel into the mason jar. Fuel pump itself is fine, and pumping fuel.

Alright, what about the fuel filter? The one installed came from the donor car, so let's swap that one out for a fuel filter we know works (the fuel filter original to the blue convertible). Swapped them over. Nada. Nothing. Well, perhaps I got the connections wrong to the fuel filter - pulled off the fuel lines from the filter, tied plastic bags around them, and turned the key. At this point, there's a puddle of fuel under my car (yay, that line is unobstructed), and I've figured out from the remaining fuel in the plastic bag which line is the fuel supply. I had the Fuel supply and return lines flipped. Here's where I got a little confused: don't our cars have returnless fuel systems OEM? what's this "return" line? Evap? Hopefully now that they're in the correct spots, the car will start...after waiting for the fuel to evaporate...nope; granted, I only had a partial charge on the battery, but I didn't hear the fuel pump prime the system again, and when I checked the schrader valve at the end of the fuel rail, nothing came out - not high pressure air, nor high pressure fuel; nothing.

Am I missing something here? Does this sound familiar to anyone? A couple days ago I had the car running with the return and supply lines backward - it was only running briefly, but could that be the culprit? Have I inadvertently injected a bunch of gunk into my fuel system by being careless?

Thank you all.

[Dr.B6Banter]

May have just been residual fuel pressure when the engine ran before on the flipped lines. The b6 is returnless but its with respect to the engine as there isn't a return line going from the fuel rail to the fuel tank. The fuel filter acts as the regulator and sends 4 bar of fuel to the engine and returns the remaining pressure to the fuel tank through said return line. Unsure what having them backwards would do. I would imagine there is a check valve inside so no fuel would flow and that would be it.

When I did my drivetrain swap, to bleed the system I just undid the fuel line in the bay and put it in a bottle and primed the fuel pump a few times.

[ImRobBailey]

So the fueling situation is figured out - I was a bozo and mixed up the lines when I thought I had them correct. So now they're actually correct - and confirmed the fuel rail has fuel and bled successfully. Fuel, check.

So now it just cranks and cranks and cranks even though it has fuel. Do I go back to basics here and pull sparkplugs, things of that nature? Anything I can do to figure out what's going on via VCDS? I have a genuine, licensed version, but not quite sure how to check specifically the things going on during ignition. Perhaps I've thrown the timing off somehow? (god, I hope not...) I did an auto scan, and noticed several faults, mostly relating to electrical connections which aren't plugged in yet (driver and passenger seat, some trunk sensor), so I cleared them, and tried cranking again, but got nowhere. I feel like I'm inches away from this baby cranking over, running and then getting this project finished.

[ImRobBailey]

Following the natural progression, I've completed an auto-scan and have copied the results below:

Notes:

ABS Brakes faults - I likely need to do a steering angle sensor calibration, but haven't quite figured out how that process works in VCDS. Continuing to search.

Auto HVAC faults: I thought these were all from the front seats being removed, but "Signal for Duration of Ignition Time off" sounds ominous. Air flow flap positioning motor is new, but I did have the climate set to "off," so I wonder if it just didn't read anything. The rear heated window has never worked - another thing to figure out later.

Airbags faults: These look to be caused by the seats being out of the car.

Instruments: I understand fuel supply sensor 2 - I haven't wired in the second level sensor yet, but I've coded the car to expect it. Supply voltage too low - is this just "charge the battery?" Engine control module - uh oh, this one looks bad. Transmission control module - expected.

Auto roof: Interesting, didn't expect to see a fault here.

Central convenience: There's a short in my horn? and I've tripped the tilt sensor.


Sunday,07,November,2021,17:43:09:33482
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 21.9.0.2 (x64) HEX-V2 CB: 0.4555.4
Data version: 20210903 DS330.0
www.Ross-Tech.com


VIN: WAUAC48H34K008257 License Plate:
Mileage: 139460km-86656mi Repair Order:



--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Chassis Type: 8H (8H - Audi Cabrio B6/B7 (2003 > 2009))
Scan: 01 02 03 08 09 0F 11 15 16 17 18 25 26 36 37 45 46 55 56 57
63 65 67 73 75 76 77

VIN: WAUAC48H34K008257 Mileage: 139460km-86656miles
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8E0-614-517.lbl
Part No: 8E0 614 517
Component: ABS/ESP front 3429
Coding: 04255
Shop #: WSC 00672
VCID: 6597B98C8C79EA83347-51F2

2 Faults Found:
01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30
35-00 - -
18256 - Please check DTC Memory of Engine Controller
P1848 - 35-00 -

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 AD
Component: A4 Klimaautomat 1219
Coding: 00100
Shop #: WSC 00672
VCID: 6393A794824D94B3DA3-513C

7 Faults Found:
01274 - Air Flow Flap Positioning Motor (V71)
41-00 - Blocked or No Voltage
00716 - Air recirculation Flap Positioning Motor (V113)
41-10 - Blocked or No Voltage - Intermittent
00975 - Heated Rear Window (Z1)
31-10 - Open or Short to Ground - Intermittent
01172 - Temperature Sensor; Driver's Heated Seat (G59)
30-00 - Open or Short to Plus
01171 - Temperature Sensor; Passenger Side Heated Seat (G60)
30-00 - Open or Short to Plus
00532 - Supply Voltage B+
53-10 - Supply Voltage Too Low - Intermittent
01206 - Signal for Duration of Ignition Off Time
27-00 - Implausible Signal

-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 8E0-907-279-8E2.lbl
Part No: 8E0 907 279 F
Component: int. Lastmodul USA 0517
Coding: 00003
Shop #: WSC 00672
VCID: 353729CC7C595A03447-4B00

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8H0-959-655-84.lbl
Part No: 8H0 959 655 B
Component: Airbag 8.4EC 2015
Coding: 0010105
Shop #: WSC 00672 785 00200
VCID: 392F25FC5541BE63A0F-5184

4 Faults Found:
01218 - Side Airbag Igniter; Passenger Side (N200)
001 - Upper Limit Exceeded - MIL ON
00592 - Seat Belt Switch; Passenger (E25)
010 - Open or Short to Plus - MIL ON
01217 - Side Airbag Igniter; Driver Side (N199)
001 - Upper Limit Exceeded - MIL ON
00591 - Seat Belt Switch; Driver (E24)
010 - Open or Short to Plus - MIL ON

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8E0-953-549.lbl
Part No: 8E0 953 549 N
Component: Lenksáulenmodul 0611
Coding: 01041
Shop #: WSC 00672
VCID: 3E2536E0496F995B95D-4B00

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8E0-920-9xx-8E2.lbl
Part No: 8H0 920 950 E
Component: KOMBI+WEGFAHRS. RB4 D17
Coding: 01201
Shop #: WSC 00000
VCID: 2E0506A0990F69DB05D-5160
WAUAC48H34K008257 AUZ6Z0C0293904

4 Faults Found:
00438 - Fuel Supply Sensor 2 (G169)
30-00 - Open or Short to Plus
00668 - Supply Voltage Terminal 30
53-10 - Supply Voltage Too Low - Intermittent
01314 - Engine Control Module
49-10 - No Communications - Intermittent
01315 - Transmission Control Module
49-00 - No Communications

-------------------------------------------------------------------------------
Address 26: Auto Roof Labels: 8H0-959-255.clb
Part No: 8H0 959 255
Component: VSG B6 CABRIO 6286
Shop #: WSC 00999 444 64523
VCID: 73B3D7D437AD0433AA3-5160

1 Fault Found:
01333 - Door Control Module; Rear Left (J388)
004 - No Signal/Communication - Intermittent

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels:. 8E0-959-433-MAX.clb
Part No: 8H0 959 433 C
Component: Komfortgerát T7B 1412
Coding: 11852
Shop #: WSC 00672
VCID: 343114C87723430B739-4B00

Component: Tõrsteuer.FS BRM 0001

7 Faults Found:
01134 - Alarm Horn (H12)
29-00 - Short to Ground
01134 - Alarm Horn (H12)
49-10 - No Communications - Intermittent
00962 - Alarm via. Tilt Sensor
35-00 - -
01368 - Alarm triggered by Luggage Compartment Switch
35-00 - -
00956 - Key 2
35-10 - - - Intermittent
01333 - Door Control Module; Rear Left (J388)
37-00 - Faulty
01334 - Door Control Module; Rear Right (J389)
37-00 - Faulty

-------------------------------------------------------------------------------
Address 56: Radio Labels: 8E0-035-1xx-56.lbl
Part No: 8E0 035 195 H
Component: symphony II NP2 0260
Coding: 13001
Shop #: WSC 74496
VCID: 2C010CA8AF231BCB2B9-5066

1 Fault Found:
00856 - Radio Antenna
29-00 - Short to Ground

End----(Elapsed Time: 06:10, VBatt start/end: 11.9V/11.8V. VIgn 11.9V)-----

[ImRobBailey]

It's been a little while...in that time, major progress has been made!

To start, diagnosing my no-start issue was super frustrating, but after a discussion with my brother on where to begin, he recommended starting with every electrical connector I had messed with, and ensuring they all had good solid connections. The connection I was most concerned with was the main ECU connection. To install a clutch switch, I had disassembled the connector, added a wire to pin #30, and reassembled the connector. However in my hurry to put it back together, I wasn't careful to ensure the internal pin assemblies were fully seated in the connector before inserting the purple locking pins. So I re-reassembled the ECU connector, ensuring a solid connection, and the car started right up. What a relief. At least it was something simple!

And so work progressed: I installed front axles and torqued them, and then tried to take the car for a spin...well the clutch felt like it went nowhere, so I re-bled the clutch, and eventually threw my phone under the car to see what was happening while I put the car in gear. Welp, it makes a lot of sense in hindsight - the 01A is an all wheel drive transmission with an open center differential, so all the power was going to the driveshaft flange, and the car wasn't moving. Still, wins all around. 1. - the transmission seems to go into gear and run without any funny noises. 2. - the clutch works! 3. - just major progress feels great.

So the car went back up on stands, and I hired a mobile welder who came through and welded driveshaft center bearing brackets to the drivetunnel. The next day the welds got a coat of paint, and I installed the driveshaft. In full transparency, I'm pretty impatient at this point, and don't really feel like rebuilding the CV joints on either side of the driveshaft, so I wash them out with brake cleaner, let them dry, and inject a fresh packet of CV grease into each joint. Perhaps someone will comment on how dumb of an idea this was; in the meantime, I'll save up for a new driveshaft (apparently they go for ~1k), and start scouring junkyards.

Installed the driveshaft and torqued the driveshaft bolts as best I could. Can't really guarantee all of them are to spec, but I did as best I could, and I think they're all pretty close. I neglected to purchase new hardware for the driveshaft, so the mounting bolts and plates are from the donor car. I'll be purchasing a set of new hardware and replacing them soon.

So the car is back together, sitting on all 4 wheels, and ready to go!

First drive, lots of rev hang, but the transmission shifted smoothly and performed admirably. No strange noises that I could tell.

Next I adjusted the clutch switch and took the car for another gentle drive around the block. No rev hang this time, everything feels great. I was pretty rushed to make sure all of my work would actually pay off, run and drive without any issues, and I hadn't yet attached the back half of my exhaust - so the car is popped and burbled down the street to the gas station to get a couple gallons. Today we'll see if the FWD exhaust will hang without interfering with the driveshaft. So far, the cat and downpipe clear the driveshaft and transmission by a couple inches, thanks to the flex joint. I'm hoping this is enough to clear the driveshaft and I can just reuse the current exhaust. Otherwise, I'll be either majorly modifying the exhaust, or purchasing an entire new system/sourcing one from a junkyard.

Heat shields. I really need to install the axle heat shields and driveshaft center bearing heat shield. Hopefully most of this will be finished today / early this week, and I can take the car for a real shakedown cruise.

There have been some funky smells, but I'm pretty sure it's just oil and greasy fingerprints burning off and the clutch bedding in. I did mention heat shields, but I didn't let the engine get up to temperature...hopefully I haven't roasted anything with my 2 minute test drive. We'll see today!

[A4SoftWalker]

^^^ This is really good to read on here. Excellent work.

Happy for you man.

[ImRobBailey]

Thank you! It's been quite the journey, and I have to admit, while it took longer than my "official estimate" of 6 months, it took less time than I expected (purchased the donor car in early March 2021, car is driveable but not fully finished by mid November 2021).

Heat shields have been installed on the driveshaft center bearing and above the front right axle, so no worry about cooking those into oblivion any more.

There is a neat little swishing sound while driving though, and I expect that my brakes are dragging a little. I'm going to drive it a bit more to see if it's just new pads & rotors bedding in, or if I need to get in there and take a look.

Unfortunately the FWD exhaust won't fit at all. The downpipe clears the driveshaft, but it's the section rearward of the downpipe that won't fit under the car - the single central resonator can't clear the fuel tank I believe. Either way, I'm now considering an aftermarket exhaust (probably a $1k borla system), or trying to modify the FWD exhaust (but eliminating the resonator will probably introduce drone), or going to junkyards and pulling an exhaust (most A4s in junkyards don't have exhausts already, and if they did, I'd need to chop the system to transport it, then re-weld it at destination, or rent a truck). For now, the exhaust dumps right out of the frontpipe which is professionally secured to a drivetunnel crossmember with baling wire...for now.

Lastly, because I'm an amateur mechanic (at best), I'll probably take the car by the local Audi tuner shop and see if they'll give it a once over and an alignment. Seems like a good idea to have someone who actually knows what they're doing take a look.

[rob.mcgeown]

Hi Rob, im just about to start the same swap here in England. You're thread will be very helpful!

Did you solve the wiring puzzle? Revers and the other 4 wires?

Thanks, also Rob.

[Mike Tries]

He may still be trying to snug those bellhousing bolts up! One click at a time!