Transmission problems

[Bratcop]

So I bought an C5 A6 with tiptronic and 4.2. I knew it had trans issues when I bought it. It would shift and drive normal until it was up to operating temp then it would slip and bang into gear from 2nd to 3rd. The tiptronic seemed to work OK on the short test drive.

Initially I thought it could be the wet passenger floor /water in TCU causing the issue. I removed the TCU, and find that it appears to have been previously accessed by PO, but no water stains.

I also noted a real seal leak at transmission.

Question is this. I am wondering if their is a way to determine if TCU is the culprit? Anyone had one go bad? What did it act like?

Could it just be low on fluid, need a fluid change? Fluid change and filter are like $100 proposition and if it doesn't fix it, it gets drained and literally $100 down the drain.

Looking for symptoms and resolutions from owners with similar issues.

Bratcop

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[alien_brain]

go to a reputable transmission shop

[Bratcop]

Well that's a useless response. If i wanted to pay someone to fix it I wouldn't
A. Be asking questions on this forum
B. Have bought something that would cost thousands to repair in the first place.

I am looking for trouble shooting advice to best resolve my transmission issues myself... Anyone else?


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[rollerton]

This is my basic boiler-plate advice for the HP29 trans problems.:

There are very few serviceable items that cause these transmissions to act up and almost all of them will throw errors in the TCU module.
IF you have no errors in the trans module then trans fluid change would be worth a try. First I would simply check the fluid level. If it's full and you can get a finger up in there (I know..that's what she said) and it's not horrifically dirty then the trans is toast.
Okay, I'll qualify that a bit; it may not be "toast" but any service of any internal part means it gets a FULL AND 100% REBUILD. You simply do not tear into one of these units unless you go all out. Any part you do not replace or fix is a liability and it will fail.
Low fluid might cause hard shifting in a single gear...or a couple. I wouldn't get your hopes up. Aside from that there's the multifunction switch on the side of the trans. If it's bad it'll throw codes. There's the valve body up inside the pan, again..they wear and can cause problems, but USUALLY don't.
I have two S6's (same trans) and they're GREAT, but I still have a 6-speed swap sitting in the shed just in case. I have a basic roughly $200 cap on what I will spend to maintain one of these transmissions. If I can't fix it for $200 it gets swapped.

Anyway, that's my take on it. I know...you can always hope but it won't do much good. My old silver S6 had an Audi 'NEW" trans installed right before I got it and holy shit it drove awesome. They're AWESOME transmissions when they're in good shape, but they're also known to fail regularly when they reach a certain age.

Tl;DR : If there are no codes then Check and top off /or change trans fluid. If that doesn't fix it it;s junk.

[Bratcop]

Thank you. I will do a full rebuild if necessary, just don't want to pull this pig if I don't need too, u know the KISS principle... Thanks again

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[alien_brain]

ok youre good now that some guy half way accross the nation has given you a few words of text on a screen... all the guys here are waiting with all the good info you need to fix your problem with a minimum of fuss. there is no need for a real expert when you have these guys! good luck with that brother! let us know how you get on

oh and remember you can always hope hahaha

[Drifters]

Bratcop, I had the same issue with the trans in my RS6 and you will need a full rebuild. It's mechanical failure and not TCU failure. Since you are in WI, I recommend getting in contact with TOZO in Schuamburg, IL and he should be able to rebuild the trans in a weekend. TOZO knows these trans inside and out and he should be able to rebuild it and install it for you.

[LakeTahoeQuattr]

Bratcop, I had the same issue with the trans in my RS6 and you will need a full rebuild. It's mechanical failure and not TCU failure. Since you are in WI, I recommend getting in contact with TOZO in Schuamburg, IL and he should be able to rebuild the trans in a weekend. TOZO knows these trans inside and out and he should be able to rebuild it and install it for you.

x2 . Yup TOZO all the way on a rebuilds.

[carmudgeon]

There's a damaged (case) transmission in the classified for sale, is it the same 5HP24 for the A6 4.2 vs the S6 4.2?

[Bratcop]

None of you guys rebuild your own transmissions? Really? I just finished an Acura 5 SPD Auto in an all wheel drive MDX. That trans was rebuilt right after I pulled the engine myself and completely rebuilt it, rings, bearings, etc. Have rebuilt and modified a Ford c6 automatic to handle the 500 HP/550tq from the stroker I built. Not really asking about repair shops, more about thoughts on cause. I will be doing this myself.

Alien brain... Not trying to offend, but seriously someone on a forum asks a diagnostic question and your response is find a shop? That might be how you maintain yours, but some of us actually do all our own work, and I mean everything except machining.

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[Bratcop]

To those of you who actually have something useful, thank you. To others, if my question was "who knows of a reputable shop in my area that can solve my problem" , you would have probably given me a great response with Tozo, however that wasn't my question. I guess first post wasn't clear in some way. Thanks for trying anyway.

Bratcop

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[G Men 08]

What exactly is a full rebuild? Just the valve body, torque converter, both?

[Bratcop]

Frictions, steels, seals, gaskets, torque converter, and anything that is broken. Valve body can be rebuilt or modified if needed.

Bratcop

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[alien_brain]

if thats not an indication ^^

was just trying to save you some time brother. but since youre superman over here nevermind.

calling all transmission know it alls! ok i just put the word out, they should be stampeding any moment now.

[G Men 08]

Damn. Level 10 it may be, then.

[LakeTahoeQuattr]

I considered rebuilding the 5hp24 from my 02 a8L. Rebuild kit on ebay is $900, ZF/audi parts are ~$1,500. Not sure if it makes a difference, everyone says to go with the ZF stuff but the reviews on the china stuff is good too. You all know this same trans was found in the range rovers, bmw v8s, audi v8s, and jaguar v8s. They suck and all have the same problems with the F seal blowing out.

I was told that rebuilding these transmissions is easier than a chevy 4 speed. If you look on youtube you will find a few people who have done it and they say it is cake. Was gonna rebuild my transmission but decided to just get a used one for 1200 and threw away the old core. At this point it is easier and cheaper to just replace with a used trans.

[alien_brain]

ding ding ding we have a winner!

at least thats how we do here. most of us.

[LakeTahoeQuattr]

Hell yea Im winner whoo hoo

[Drifters]

Bratcop, not to get defensive here but I thought I answered your questions. I said that it's mechanical failure and not the TCU failure (as I had the exact same thing you described).

Go ahead and rebuild it yourself if you want but you have a ZF Trans expert near you in IL (TOZO) as an option if you don't want to rebuild it yourself. The ZF trans is known to fail. Getting defensive when other members are giving you options and advice makes no sense.

[Bratcop]

I wasn't defensive at you drifters, but I was with the first responder and his continued sarcasm... Needless to say I appreciate the shop info and insight into my issues. Like I said it's probably an awesome solution if I was paying someone to do it. And you are probably correct it's a mechanical failure

It's just that when I detailed the issue asked about anyone with similar issues and the response I get is find a shop, I was a little dumfounded. Anyway again thanks to all who provided useful insight.

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[rollerton]

None of you guys rebuild your own transmissions? Really? I just finished an Acura 5 SPD Auto in an all wheel drive MDX. That trans was rebuilt right after I pulled the engine myself and completely rebuilt it, rings, bearings, etc. I will be doing this myself.
but some of us actually do all our own work, and I mean everything except machining.

Sounds like you might be able to do it. Most of us don't because it's a huge pain in the ass and if you haven't done at least a few technical rebuild of auto trans's then it's a total nightmare. Personally? No thanks. Considering how often even reputable shops WITH all the right tools and a trained tech fuck these units up, I'll pass on doing it myself.
Besides that, you absolutely NEED the shop manual and tolerances and torque specs etc etc.. or else how do you even know if the parts you're sent are even right?
Sourcing even a proper rebuild kit feels sketchy.
I'm game for opening up a manual trans usually if I know a bit about whats wrong with it. Also I'll let someone else handle the liability of it having an issue once it's all put back together. Picture doing the rebuild meticulously, every single nut and bolt and drum and clutch is absolutely perfect.
NOTHING went wrong and you reassemble it and it SLAMS into gear in the first 100 feet No way. I can't afford enough whisky to go through that.
I'd be one person who might be cheap enough to try AND I have a perfect 5hp24 trans sitting in my shed. 4k on a rebuild and reverse drum failed. Even with that thing sitting there I don't think it's worth it. So, if you need a spare trans' to get started on I've got it!

Let us know how it goes...and post details when you do it!

[Bratcop]

Yeah, that would suck if it failed immediately or ever, but I could accept that if I did it. What I couldnt accept is paying thousands to someone who is a professional and having that fail 😣. I trust me more. Thanks for the advice and to all that felt i was harsh, I apologize.
Bratcop

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[Grigor@Bestiale]

Does anyone know if Tozo is still as good as you guys say he is? Is Tozo the person or is that the shop name? Could someone share contact information like phone and address?

Thanks in advance!

Bratcop, not to get defensive here but I thought I answered your questions. I said that it's mechanical failure and not the TCU failure (as I had the exact same thing you described).

Go ahead and rebuild it yourself if you want but you have a ZF Trans expert near you in IL (TOZO) as an option if you don't want to rebuild it yourself. The ZF trans is known to fail. Getting defensive when other members are giving you options and advice makes no sense.

[C5S6]

I have no 1st hand experience with him, but browsing these Audi forums for 15 years, I know he's been around and has a solid reputation when it comes to rebuilding the 5HP24A and other ZF transmissions.
I believe his actual name is Gabor and he does frequent Quattroworld's D2 & Off-topic forums. His screen name there is TozoM8, email tozoa8 [at] yahoo [dot] com.

[Grigor@Bestiale]

Thanks a lot C5S6! Much appreciated!


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[Scotty@Advanced]

Search these forums and you will find that a few people have "Rebuilt" their automatics with little success several times. Regarding 5HP24's Gabor (ToZoM8) is the best out there.

- - - Updated - - -

Yeah, that would suck if it failed immediately or ever, but I could accept that if I did it. What I couldnt accept is paying thousands to someone who is a professional and having that fail 😣. I trust me more.

That's what reputation and a warranty is for.