luvofjah

iTrader: (2)

Street use... but want something more powerful than stock auburn...

I know the difference, Posi uses clutches, TrueTrac uses gears, & Locker racheting gears....

10 Bolt, 3.42 Gears, 28 Spline, 5 speed TPI...

I've seen some people say they would not use a Posi on a stick shift car... ???

So what would be best in my 5 speed car mostly street use... but i may up at the track after all these parts get put in

Rafael

big gear head

There is no reason not to use a Eaton Posi in a car with a manual transmission. The Eaton Posi was the only limited slip differential used in the Chevy muscle cars from '65 to '72 and it did very well in them. All of the muscle cars used a clutch type differential except for the very few that got a Detroit Locker.

If this is a street/strip car then the Eaton Posi will work well. If you want to do more auto cross or road racing then the Truetrac or Torsen would be a good choice. The locker would be for a serious drag car that gets used on the street some.

luvofjah

iTrader: (2)

So pros & cons vs posi / truetrac... Aren't the both limited slip? Locker, for me would not be a good choice...

I may be able to get a deal on a truetrac... And hope to add more power down the road...

big gear head

The Truetrac works well most of the time. I have heard a few people say that they had a hard time getting theirs to lock up at the drag strip. I think they work smoother for road racing or auto cross. The Eaton Posi can be tuned for your needs if that is important. There are many clutch sets and springs available to set them up. That does cost extra, so most people are just going to run them like they are. I think they work better for drag racing, but not as well in tight turns under power.

luvofjah

iTrader: (2)

The Posi....?

big gear head

Yes. I don't think the clutch type units are as smooth in a turn as the gear type. The clutches slipping and grabbing could cause some loss of traction in a turn. That's just my opinion.

luvofjah

iTrader: (2)

I'm driving in Florida, no snow

Found this...

The HUGE advantage of the Torsen Differential (Torsen stands for Torque Sensing) is that it puts the power to the tire with the most traction. A Posi-unit does the opposite...it puts the power to the tire with the least traction. This tendency is only countered by the friction force between the clutch plates.

big gear head

I wasn't talking about driving in the snow, I was talking about auto cross or road racing.

luvofjah

iTrader: (2)

Yes, I was just putting up more info about my intended driving... car has upgraded suspension, SFC's, Jet Hot Hooker 2055's, 3' exhaust, etc...

I think I'm going to try for the TruTrac at a savings... been reading a lot on other forums for all sorts of cars and people are very happy with it... Some say a little tire chirp on sharp corners, otherwise works great...

big gear head

The Truetrac does not use the limited slip oil additive, so just use straight gear oil in it.

luvofjah

iTrader: (2)

Ya, picked up a new one for $280 shipped on ebay this afternoon

Raf

luvofjah

iTrader: (2)

Well... last post was August 2013... just bought an "eaton truetrac" for $280... Then slowly got other parts... found a 10 bolt from craigslist of a 91 for $60. Had it taken apart, tubes welded and tabs for LPW brace kit, found some Richmond 3.42 gears (stock ration for my Formula), Motive Gear Factory 10 28 spline axles, took it all to a mechanic in February 2014 for assembly... a week or 2 into the rebuild he calls and says, this "eaton truetrac is not correct"... They ebay guy sold me one for a Ford 9"

I was well past the 45 days (6 months) and of course no reply...
Of course the "seller" didn't say a thing... Partly my fault for not checking, but many of the places I looked (before I got it) all said "picture represents item, actual item may be different"..... And I've never taken apart a 10 bolt or Ford 9"....

So... Summit had the correct new Eaton TrueTrac for $405.... Plus Eaton had a $50 rebate for any purchases over $400, so I paid $355.
Since the Ford 9" is a very desirable rear end, the part I paid $280 for resold on Ebay for $400

I picked up the Spohn Torque arm used for $75, the cross member with drive shaft loop for about about $150 new from Spohn during Thanksgiving sale...

Stopped by the shop today... rear end, torque arm rear drum brakes all in...
Working on the front end brakes now (Clutch, Pressure Plate, Flywheel, Spohn Cross Member are all in...)





Should be ready to take home Saturday!

I also got a new McCleod 11" clutch, pressure plate and GM Flywheel installed with new master / slave for clutch and brakes, etc...

Rafael

big gear head

Nice.

I H8 WWD

iTrader: (5)

So I'd take it this would be best for a drift inspired setup. I want the rears to lose traction very easily. 4.10's with a Torsen and 28spline axles and some bracing. I think I'm in for a nice rear end setup for my IROC.

I was going with the Eaton Posi. I'll research these a bit more.

big gear head

No, a "posi" (correct name is limited slip differential) will apply power to both tires until the clutches are over come by the torque difference between them. As long as the clutches are in good condition and the preload is set correctly it will lock up very well in most situations.

If you want to build a car that is only to be used for drifting then a spool should be used. If it will be used on the street any then a spool should NOT be used. A locker would be better if it will be used on the street.

I H8 WWD

iTrader: (5)

Grr. From Auburn fine to Eaton ready to Torsen possibly, now to a Locker. Lol. I've been told/read so many different things to use for drifting. I don't think I'd go wrong with any of them in the end over the stock open-diff. Eaton was my original choice. Thanks for the explanation.

The idea behind my car is to be able to (as close and as much as I can) make the car adjustable for any auto-sport. Drag/Drift/Track/Auto-X as well as being a daily driver. I don't care about vibrations or creeks of metal on metal. As long as it's legal for the road, I'll drive it on the street. Just need to find what works best with this concept.

big gear head

There is no single differential that will work great in all of those conditions. A locker will work great for drag racing and drifting, but not too well for auto cross and road racing. A Truetrac or Torsen will work well for auto cross and road racing, but might not lock up completely when drag racing or drifting. The Eaton Posi works very well for street use and also works for most of the other uses, but might slip when pushed to the limit. There are also differentials like the ARB and Eaton E Locker that can be locked and unlocked, but are expensive and more difficult to install.

I H8 WWD

iTrader: (5)

I hear you. I want too much lol. Maybe I'll carry a spare rear end with me lol.

Well thanks for the added information. I was sure you'd get mad having to explain this to me better than already was. It appears the Eaton will be the best, especially since it'll see more street than the others, maybe. I'll just have to build it super tight.

P.S. I need more drifting buddies.

slow305

iTrader: (2)

Nearly a 100% autocross car, I just went with an Auburn race diff after the Torsen T2R blew up. Granted the Torsen has been in the car for 14-15 years (three previous owners) but I've had friends with 4th gen F Bodies (autocross cars, too) fry T2Rs during that time. Haven't heard much on the Eaton for autocross use and didn't feel like being the guinea pig!

This is on an OEM 10-bolt rear.

And the Auburn can be rebuilt for about $200. Probably just get it rebuilt before the Solo Nationals every year.

Pat