Trani Experts: Quattro and FWD trani the same? Tailpieces interchangable?

[andyrew]

All,

Are the tailpieces interchangeable between the quattro and FWD trani's? Basically what im asking is can you make a Quattro trani a FWD trani simply by bolting on the FWD tailpiece? Is there something more to consider?

If this is true, does it work for the automatics as well as the manual's?

Thanks!

[blacka4]

they are not the same. One is longitudely mounted and one is transversely mounted.

[hercfe]

they are not the same. One is longitudely mounted and one is transversely mounted.

Nice avatar bud! Hockeytahn!

Seriously, I spit up my coffee when I read the OP's post. That may be the most ridiculous thing I've read on here-and I've seen some real baloney. The question is, WHY would you want to make your quattro FWD? if anything, I could MAYBE see plugging the front axle receivers and making the car RWD-but that would still be kinda-no, really stupid.

[andyrew]

Black, What are you smoking? They are both longitunally mounted aka Transaxles..

the TT FWD has a transverse style trani, however it has a transverse AWD setup as well..

This setup is NOT for an A4, this would be a custom application. Trust me, the reasoning is sound. :)

Heres a pic of the FWD trani I found on a quick google search.


S4 trani (couldnt find a 5 spd)

[blacka4]

oh I'll admit I was mistaken. I have never actually seen a FWD A4 so i just assumed it was transversly mounted. i learned something new today...But, I'm stlll sticking with my You can't just swap tail ends to make a quattro car FWD and visa versa. This would have a lot to do with the TROSEN center Diff. Same theory applies as when you break a half shaft your car goes doesn't move.

[andyrew]

Well, I have heard from some of the guru's a while ago that the inners of the trani's are the same, so one would think that bolting the tail piece would theoretically fix that.. Besides the tailpiece would go on before the torsen diff. At least thats how it would be in my head..

When the subaru guys convert it the trani's to 2wd they have to weld the shaft so their is no power going to the rear, Its still an open diff though and functions like a proper 2wd.

Maybe someone has some cutaways of the two trani's? I havent been able to find anything on the issue..

[blacka4]

i know in the 6 months of research I have done on the Quattro ZF transmission (5HP-19FLA) The difference between the model for the FWD (5HP-19FL) is the A means AWD. I can't speak on the internals being the same but the FWD is thethe same transmission as the porsche Boxter. i don't see how bolting up a different tail shaft will make it FWD. IF it was truely that easy, then there would be more converstions from FWD to Quattro.

In looking at the picture above the transmissions look simailar up to a point so you might be okay. But I wouldn't try it. Not quite sure why you want to do this but it doesn't seem very cost effective

[andyrew]

Well... Truth be told ive been trying to find FWD 2.8 parts cars for my 2.8 swap w/ trani into my 914.. I need the whole wiring, dash, engine/trani/ecu/ ect so its cheaper for me to find a wreck... However everything I find, be it 2.8 or 1.8 is quattro! I'd rather not buy a whole trani to have it shipped when I can probably get just a tailpiece pretty darn cheap from someone's high milage trani...


Yes, I know they are the same trani as the boxster :) which is why I suspect they are hard as Fck to find... the boxster trani's are 1-2k..

[blacka4]

ahhh.

[BlkBullitt]

Looking at the service manual the 012 FWD 5-Speed and the 01A AWD 5-Speed appear to be similar in design in many ways, however, converting one to the other wouldn't be a simple task.

To understand why you first need to know how the transmissions function. Both have the upper input shaft and a lower output shaft. The FWD transmission simply has a solid output shaft that runs from the backplate of the FWD transmission housing to the front of the transmission (where the front differential is). The output shaft has the final drive pinion on the front of it and it drives the front differential which drives the front wheels of the car.

FWD:


The AWD transmission has a hollow output shaft meaning it has an inner and an outer shaft that can move at different speeds relative to one another. The outer portion of the hollow shaft runs from the front on the transmission housing (just behind the front differential area) to the back of the transmission housing and into the input of the center differential. The center differential has two outputs one is out the back of the AWD transmission (the prop shaft flange) to send power to the rear differential and the other output is the inner portion of the hollow shaft which runs back up to the front differential (inside of the output shaft) and drives the pinion gear to the front differential.

AWD:


So, could you make an AWD transmission FWD? Maybe... assuming the main transmission casing is the same between the two... however you would still need to change to the soild FWD output shaft (I doubt the AWD hollow shaft would hold up for very long with all of the power traveling through it to a welded up center differential and back up to the front differential) and the FWD transmission back plate. You may or may not also need different bearings and races as well when changing between the two. So even if it could be done it would probably be 1. cheaper and 2. less of a headache to just buy a FWD transmission.

Hope that helps.

[andyrew]

Wonderful imput!!! Helps MUCHO!!

I think the subi's have the same shaft thing, They simply weld the shafts together. However im probably wrong..

Thanks!

[Scotty@Advanced]

All,

Are the tailpieces interchangeable between the quattro and FWD trani's? Basically what im asking is can you make a Quattro trani a FWD trani simply by bolting on the FWD tailpiece? Is there something more to consider?

If this is true, does it work for the automatics as well as the manual's?

Thanks!

No they are not the same. The diff housing is the same and eveything on the input shaft interchanges, however the output shaft is entirely different.

To convert an AWD to 2wd or vice versa you'd need the the output shaft, ring and pinion and all associated gears that correspond to the proper input shaft gears.

As BlkBullit said it's easier/cheaper to just find the box your looking for versus converting one.

This applies to just about any Audi quattro manual transmission made in the past (016,01E,01A,01X,0A2 etc).

[BlkBullitt]

No they are not the same. The diff housing is the same and eveything on the input shaft interchanges, however the output shaft is entirely different.

To convert an AWD to 2wd or vice versa you'd need the the output shaft, ring and pinion and all associated gears that correspond to the proper input shaft gears.

As BlkBullit said it's easier/cheaper to just find the box your looking for versus converting one.

This applies to just about any Audi quattro manual transmission made in the past (016,01E,01A,01X,0A2 etc).

Thanks Scotty for the verification. I've never seen a FWD transmission in person (so diagrams are my only references), but I've seen threads on other boards of people putting together kit cars and wanting to de-AWD transmissions to use in their kit cars being warned that transmission failure is most likely due to the hollow shaft not being able to support all of the power going through it.

[andyrew]

Thanks for the verification Scotty! I now know I need to suck in my gut and keep waiting for the perfect parts car!