RayCR
RayCR
2/29/12 7:01 p.m.

I'm looking for a limited slip diff for an 80s Olds Toro front wheel driver. It's got a 455 and is raced on a twisty dirt track. Has anyone used this setup? I know that a locked or spool just doesn't work.

Streetwiseguy
Streetwiseguy SuperDork
2/29/12 8:20 p.m.

Eeek. Being an old GM product, it may very well have a common 10 or 12 bolt diff stuck in the TH425, but I think you need to find a trans shop somewhere with an old grey haired guy shuffling around to get the right answer.

Rob_Mopar
Rob_Mopar Dork
2/29/12 8:30 p.m.

If it's running the '80's transaxle it's a TH325 if it's a 3-speed and a 325-4L if it's a 4-speed.

If you are running the transaxle from the '70's Toronado that donated the 455, then it's a TH425 transaxle.

The TH425 was used in the GMC motor homes, and from what I understand an aftermarket limited slip carrier of some sort was developed for it. But it might be a unicorn too.

If you are running one of the TH325's, they seem to be somewhat popular in the V8 Fiero longitudinal swaps (think kit car Lambo conversions) so there might be something to be found with that crowd.

I don't know what differential was used in either case. It might have been based on one of the regular RWD GM rear diffs, or it could have been something unique to the 325/425.

I've never seen any talk on swapping the ring & pinion in one so I suspect it's a unique piece to the transaxle.

T.J.
T.J. SuperDork
2/29/12 8:57 p.m.

I clicked on this thread because I thought it was going to be about lawn mower racing.....that would be pretty close to grass roots.

I googled for about 20 minutes. Didn't find anything

RayCR
RayCR New Reader
2/29/12 10:38 p.m.

I'm running the 80s 3 speed the 325. The ring and pinion is differant as the pinion is hollow and slips over the trans output shaft. The car runs like a bat outa hell but spins too much in the corners.

RexSeven
RexSeven SuperDork
2/29/12 11:00 p.m.

Engineered Performance makes (made?) an LSD for a bunch of GM FWD transmissions. I don't see a TH325 listed, but maybe they can point you in the right direction if they are still in operation. The site hasn't been updated since 2004...

http://www.engineered.net/eplsd.htm

http://www.engineered.net/contact.htm

MG Bryan
MG Bryan Dork
2/29/12 11:22 p.m.
T.J. wrote: I clicked on this thread because I thought it was going to be about lawn mower racing.....that would be pretty close to grass roots.

I was hoping someone was building a locost based on a Toro Workman...

bravenrace
bravenrace SuperDork
3/1/12 5:56 a.m.

Toro's respond better to cocaine.

mad_machine
mad_machine SuperDork
3/1/12 7:45 a.m.
T.J. wrote: I clicked on this thread because I thought it was going to be about lawn mower racing.....that would be pretty close to grass roots.

I think maybe a spool would be better.. unless you toro is one of those "zero turn" models

bravenrace
bravenrace SuperDork
3/1/12 8:03 a.m.

In reply to mad_machine:

+1. I have one of those and a spool really woudn't work.

cwh
cwh SuperDork
3/1/12 9:12 a.m.

Didn't the early Toros do pretty well at Pikes Peak?

RayCR
RayCR New Reader
3/1/12 6:28 p.m.

My car is the blue and yellow #38. Give it a watch. I could use some sort of lsd and more gear, the best GM offered was 3.36:1 in turbo rivieras, what I've got are in the 2s.

http://www.youtube.com/watch?list=UUxSS-97y5DNMcm6qMUct5jw&feature=player_detailpage&v=gz6xVsDpPwc

http://www.youtube.com/watch?feature=player_detailpage&list=UUxSS-97y5DNMcm6qMUct5jw&v=OY--Q8TyHeA

mad_machine
mad_machine SuperDork
3/1/12 10:57 p.m.
cwh wrote: Didn't the early Toros do pretty well at Pikes Peak?

well.. there is no grass at the top anymore

RayCR
RayCR New Reader
9/1/12 8:59 p.m.

Found one! Engineered Performance will build one. Jeff said that he would like to build more than one, so, if anyone would like to have a limited slip diff for their 78 to 86 Riviera, Eldorodo , Seville or Toronado give them a call at 404-394-5776 or email them at tech@engineered.net. And tell them Ray sent you.

DWNSHFT
DWNSHFT HalfDork
9/3/12 10:05 a.m.

Bummed... thought this was gonna be about snowblowers...

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