Does anyone know anything about a Tremec Transaxle?

Doug Sainlar · 12-12-06, 12:58 PM

I was reading in one of the kit car magazines an article about a very unique Cobra replica that used a drivetrain similar to the new 'Vettes with the engine connected to the transaxle via a torque tube. What caught my attention was the mention that the next "prototype" would be different in that it would use a Tremec Transaxle.

That is not a unique setup--somewhere in the back corners of this brain there is a memory that the Pontiac LeMans used a transaxle during it's early production in the early 60's. Obviously, by the time Pontiac stormed the muscle car market with the GTO in l964 (which was just an option on the LeMans, much like the Z28 was just an option on the Camaro), they were using a traditional transmission/driveshaft/differential setup.

Considering the difficulty transaxles cause in completion of our 40's, I was just wondering if Tremec might have any form of solution here.

Of course, since I'm not at the build stage yet I haven't investigated any further, but many of you are approaching this issue and if Tremec has something new in the works it might bear investigating.

Doug

Lynn · 12-12-06, 01:38 PM

2005 and later Corvette have this: see Car Connection article of 08/02/04. Not sure what the Cobra was using, but Porsche front engine cars use this type of set up. I am sure there are others that someone will tell us about that could be what was used.

They call these transaxles, which I guess they are, since the transmission and diff are in one case. However, they have a longitudinal layout that has the tranny first and then the diff; not to mention having to figure out a bell housing. I am sure I am preaching to the choir here; they really need to come up with another term to describe this setup with a torque tube. Maybe "TT-transaxle" or remote-mount transaxle.

Lynn

woodz428 · 12-24-06, 11:51 AM

Quote:

Originally Posted by YerDugliness

That is not a unique setup--somewhere in the back corners of this brain there is a memory that the Pontiac LeMans used a transaxle during it's early production in the early 60's.
Doug

Yes the Tempest used an independent suspension with transaxle and torque tube. Actually the "torque tube" was a large daimeter braided cable that was used to "bend" the thing under the floorpan for more leg room. The tansaxle was really a slightly modified Corvair transaxle. It mounted similar to the Corvette one with the trans in the front and the diff behind...exactly as the Corvair had it mounted. The automatic ones,powerglides, had the torque converter hanging on the back . It's been about 5 years since I last worked on one, but I seem to recall it having an exposed torque converter.

Ron Earp · 12-24-06, 11:55 AM

If I am not mistaken Corvettes have had that layout since the C5 introduced in, what, 1997 or 1998? So, one should be able to find the unit used these days. Have to agree with Lynn, they are transaxles but not in the purest sense of the word.

R

Lynn · 12-24-06, 12:17 PM

Don't know for sure, but it is possible that prior to this Tremec, the transaxles were made by ZF. Vettes had been using ZF gear boxes for most of the '90s

Lynn

Dave Decker · 12-24-06, 02:39 PM

The ZF used prior to '97 in the 'Vette was a conventional gearbox. I've considered using the Tremec transaxle for a mid-engined project. The obstacles to overcome are; the shifter, which comes out just above the input shaft and would interfere with the pressure plate; the input shaft; which would have to be machined or swapped out for a Camaro/Firebird input shaft; the length of the unit, which could be solved with the cogged belt drive unit I saw in the forum a couple months back. I think the front housing of the Vette tranny could be swapped with one from a Camaro and that would sovle the bellhousing issue. If I remember right, the length of the transaxle from the front mounting face to the centerline of the drive axles was 23 1/2" Hope this helps, or at least doesn't confuse any further. Cheers, Dave

Lynn · 12-24-06, 03:41 PM

Dave,

IMHO, the obstacles make its use in a midengine layot very unattractive; especially, when there
are more suitable alternatives available.

Now if someone were building a roadster, I think this drive train would be an outstanding choice.
In something like a Lister or one of these Kellison J-6s

or even something like a Jag 120 replica, I think it would make the weight distribution, in some ways,
as good as or better than a midengine layout.

Lynn

pete · 01-31-07, 12:05 AM

Rearend Gear Swap some good pics here - looks like not a very good canadate.

pete

Keith Hardy · 01-31-07, 07:00 AM

Phew! What you'd call a Quick Change Rear End. NOT !!!

Peter Olliviere · 01-31-07, 07:28 AM

Lynn,
As to the layout of the diff and tranny in Vette you are correct but as to the Porsche, the transaxel layout is the same as with the 016 and 01E. The 016 being used in the 924 through 944 Turbo and being replaced with the 01E in the 968. This setup would work for a V8 powered front engine replica or one off, especially the 968 setup with the 6 speed 01E.

Unfortunately for us Porsche decided to modify the bellhousing to fit the torque tube, removing the mounts for the throwout bearing on these transaxels and thus forever being regulated to a footnote in the GT40 community.

Peter

Ken Grulich · 02-22-07, 12:46 PM

I know it may not help everyone, but I did find someone who successfully mated the Corvette transaxle directly to the back of the engine. He put the whole assembly in a Corvair. The only caveat is that he used an automatic. I just came across this information, and I am trying to get in touch with him. Here is a link that shows his car and a pic of the engine/trans combo. For my custom project, I think this may work. I like it because of the increased availability of the pieces, and their ability to take more power.

After visiting Fran's shop (fantastic by the way) I was pretty set on the Audi unit. However, I can't help but think about adding more power down the road. This could be a good alternative for people making their own car, like me.

Phillip West Corv8

Thanks
Ken

VairKing · 02-22-07, 02:44 PM

Having seen Phil West's Corvair in person, I would caution that the entire length of the powertrain is very long. Even in the Corvair, there is hardly any room between the steering wheel and the front seat. OK for a racecar, not so good for a street machine...

Ken Grulich · 02-22-07, 03:08 PM

Quote:

Originally Posted by VairKing

Having seen Phil West's Corvair in person, I would caution that the entire length of the powertrain is very long. Even in the Corvair, there is hardly any room between the steering wheel and the front seat. OK for a racecar, not so good for a street machine...

Do you have a way to get in touch with Phil? He only lives about an hour from me. I would love to see the car and ask some questions. In other forums, he said he would be offering kits, but I have been unable to find a recent email address.

I am building a car from scratch, so I could work around the packaging. I was just looking at some pics of the Factory Five GTM (almost exactly what I am building). From my estimate, the overall length of the car wouldn't change much, but the wheelbase will obviously grow. That will probably decrease the turn in feel of the car, but make it more stable at speed.

Thanks
Ken