[V8] 5-speed to auto conversion

[Roger M. Woodbury]

I came to my senses and I suggest you do also.

Over the past six months I did an ENORMOUS amount of research into 
something similar to  yours. In the end, I did the correct thing which 
was less than nothing and now my V8 is gone to someone much younger who 
is bitten by the bug.

My desire wast to transplant a 3.6 liter V8 into an Audi 100 Avant which 
would be relatively simple as the automatic transmission involved could 
remain in place.  ALL the BTDT wisdom said "no", but all of those guys 
had experience doing five speed conversions into formerally I-5 or V-6 
cars.  I dug hard for ALL the information I could find about parts and 
parts and parts and how-to's.

Simultaneously my beloved (and I MEAN beloved) V8 developed a shudder in 
the transmission particularly in first gear.  It wasn't much but it 
wasn't right.  Being gentle on the gas while accelerating form a 
standstill was helpful, but a transmission service didn't cure the 
problem:  the diagnosis was that the clutch pack wasn't grabbing the 
first gear properly and SOONER rather than later, the transmission 
clutch pack at least would "grenade".

My car had a bit more an 110,000 miles on it from new and I had owned 
the car nine years. It had seen little winter miles in Maine and when I 
first bought the car with 65,000 miles from new, the undersides and 
engine, inside all covers as well as just inside the bay, were 
spotless.  NOW however, my mechanic of twenty years told me that the oil 
cooler and cooler lines for engine and transmission were pretty badly 
corroded and would have to be replaced once I decided to do with the 
transmission.

The rest of my story is not relevant to you and your desire to transform 
your nice black V8 into an Automatic.  I will tell you at the end of 
this what I ended up doing.

As my mechanic told me and so did everyone else, the devil is in the 
details.  In my case the oil cooler and assorted lines for the automatic 
transmission seems to no exist anywhere in the world. Period. Maybe it 
does, but after nearly a month of hunting, I couldn't find one.  It CAN 
be fabricated of course, but that will add some hours to the R&R of the 
auto transmission in my car.

It's been pointed out that the software is an issue with your swap.  
That's correct. Also the engine ECU will need to be changed.  Then there 
is ALL the other issues, which take time and money, unless you want 
something that's sort of cobbed together. I hope you can see how 
"chopping off the clutch pedal" in your car points to the severity and 
difficulty the entire project will be should you persevere.

In the end, there still are a few V8 Quattros with the ZF transmission 
still wandering around and occasionally available. Buy the nicest one of 
those you can find and save your black car for parts.  A running V8 in 
the hand is worth a lot as a parts car because a lot of those parts in 
your running car don't exist anywhere on the planet at this point.

What I did was bow to REAL wisdom:  My V8 is gone, sold for small 
dollars to a very nice young fellow who can have a nice V8 of his own, 
if he is patient and devotes time to the project that it will require.

In your case, you will probably need to plan on at least twenty hours of 
shop labor time to REMOVE the 5-Speed and shove in the ZF automatic.  
That will not include the fabrication of the body to accept the new 
transmission tunnel cover, and assorted other stuff, nor the 
reprogramming of the control units and miscellaneous wiring.  I'll bet 
even if you do a lot of the detail work yourself, if your leg hurts now 
from the clutch, once you have the automatic installed and working, you 
may find your left leg won't support you well enough for  you to slip 
beneath the wheel:  this is a REAL PITA job, and you certainly need to 
question whether or not it's worth it.

Oh, yeah, now if I might:  on the subject of the automatic 
transmission.  Everyone reading this who hasn't nodded off yet, probably 
knows that this transmission wasn't rocket science as such things go.  
It's a relatively simple ZF 4HP24 transmission used in may higher end 
cars during the late 1980-'s-and 1990's. The ONLY difference is that the 
Audi Quattro system used a variant indicated by an "A" at the end of the 
nomenclature.  This transmission....ZF 4HP24A....is no longer available 
ANYWHERE off the shelf in ANY form as far as I could determine.  
Furthermore, it is NOT readily rebuilt or remanufactured by ANYONE that 
I could discover after two weeks of hunting, EXCEPT for two rebuilding 
firms on the west coast.  The good parts are that those two rebuilders 
will only rebuild YOUR own transmission as they have no cores: the 
cost?  $2800 INcluding shipping which isn't bad.  Those are the ONLY 
good parts.  ZF itself, the ORIGINAL manufacturer, NO longer supports 
the transmission and does NOT rebuild them in it's own remanufacturing 
facility here in the US or anywhere else.

I was ready and willing to have my mechanic yank my automatic 
transmission, pallet it, and have the truckers pick the thing up for 
shipment to Oregon for overhaul.  Then I figured out how much it was 
REALLY goiing to cost to R&R MY transmission and get my car back an 
ready for another few years...bear in mind I don't have to drive my V8 
in the winter at all.  When the REAL numbers passed $6,000 I gave up.  I 
also will was planning on new rear brakes next year, and a major engine 
maintenance (timing belts, etc) service sometime in the next twenty 
months. Realistically speaking much past 120,000 miles and I knew I 
would need new front brakes as well, and UFO's are harder and harder to 
come by, so I didn't even want to think about what new front brakes 
might cost at that point)  All in all I was seeing I would have a nice 
looking V8 into which I would be putting at least ten grand or more over 
the next two years and suddenly for me, it made NO sense at all.

As I see it there are some issues that may not be surmountable. The Audi 
V8 Quattro is simply too old to keep in service except as perhaps a 
summer weekend playtoy.  Audi does NOT support its cars much beyond ten 
years and the newest V8 is now twenty-four years old, and very few were 
even imported for sale after 1992. If you have very deep pockets and an 
unlimited desire to have THIS one car just so, well and good. But to do 
this job right, I think you are almost into Porsche Restoration Money Time.