Are Open Differentials That Bad?

[pontiacgp]

and LSD was known by a bunch of names...funny how you don't see positraction which I think is GM's trademark

I guess my GP had a Safe-T-Track

* Alfa Romeo: Q2
* American Motors: Twin-Grip
* Buick: Positive Traction
* Chevrolet/GMC trucks (after 1973): Gov-Lock
* Chrysler: Sure Grip
* Ferrari: E-Diff
* Fiat: Viscodrive
* Ford: Equa-Lock and Traction-Lok
* International: Trak-Lok or Powr-Lok
* Jeep: Trac-Lok (clutch-type mechanical), Tru-Lok (gear-type mechanical), and Vari-Lok (gerotor pump)
* Oldsmobile: Anti-Spin
* Pontiac: Safe-T-Track
* Porsche: PSD (electro-hydraulic mechanical)
* Saab: Saab XWD eLSD
* Studebaker-Packard Corporation: Twin Traction
* TVR: Hydratrak
[*]

 

[chevy2480]

Is going to a posi unit on a 7.5 rear end going to significantly shorten it's life? Lets say you were running around 250-300whp, with no more than 275 street radials.

Yup defiantly the 7.5 are junk get it to hook good with radials and it will most likely go

 

[pontiacgp]

Is going to a posi unit on a 7.5 rear end going to significantly shorten it's life? Lets say you were running around 250-300whp, with no more than 275 street radials.

Yup defiantly the 7.5 are junk get it to hook good with radials and it will most likely go

the 7.5 is not junk.....look how many gm's are still out there with the original 7.5....for the purpose they were meant for there is nothing wrong with a 7.5

 

[tc1959]

Is going to a posi unit on a 7.5 rear end going to significantly shorten it's life? Lets say you were running around 250-300whp, with no more than 275 street radials.

Yup defiantly the 7.5 are junk get it to hook good with radials and it will most likely go

the 7.5 is not junk.....look how many gm's are still out there with the original 7.5....for the purpose they were meant for there is nothing wrong with a 7.5

My 7.5 is 32 years old still going strong. had to replace the pinion brgs about 20 years ago ,no other problems.

 

[chevy2480]

[
the 7.5 is not junk.....look how many gm's are still out there with the original 7.5....for the purpose they were meant for there is nothing wrong with a 7.5[/quote]
My 7.5 is 32 years old still going strong. had to replace the pinion brgs about 20 years ago ,no other problems.[/quote]

Well i suggest you remove the factory motor that lacks power and put something in your car that pushes 300 whp which is what he is asking and maybe you will have a different opinion. You will be lucky if a stock motor in any gbody put more than 280 at the motor let alone at the rear. If its stock powered then it will last otherwise JUNK like I said.

 

[pontiacgp]

Well i suggest you remove the factory motor that lacks power and put something in your car that pushes 300 whp which is what he is asking and maybe you will have a different opinion. You will be lucky if a stock motor in any gbody put more than 280 at the motor let alone at the rear. If its stock powered then it will last otherwise JUNK like I said.

"if it's stock power then it will last"....since that is the case they are not junk....junk is something that cannot handle what it is suppose to handle...and the 7.5 will handle more than stock power and I have seen them take a beating in circle track racing..they run 602 crates with an HP holley pushing out about 360 hp..the weak point is the 26 spline axle. I don't know what kind of experience you have with them but maybe your not building them right

 

[tc1959]

[
the 7.5 is not junk.....look how many mg's are still out there with the original 7.5....for the purpose they were meant for there is nothing wrong with a 7.5

My 7.5 is 32 years old still going strong. had to replace the pinion brags about 20 years ago ,no other problems.
It's a factory limited slip.I run a full roller 350 & a 700R4, all is good. I wouldn't drag race with it but for every day driving it holds up fine.They are in about a million S10s and some hot F-Bodies,G-Bodies ect ....
You can break anything if you abuse it enough.

 

[cdg1984]

[
the 7.5 is not junk.....look how many gm's are still out there with the original 7.5....for the purpose they were meant for there is nothing wrong with a 7.5

My 7.5 is 32 years old still going strong. had to replace the pinion brgs about 20 years ago ,no other problems.[/quote]

Well i suggest you remove the factory motor that lacks power and put something in your car that pushes 300 whp which is what he is asking and maybe you will have a different opinion. You will be lucky if a stock motor in any gbody put more than 280 at the motor let alone at the rear. If its stock powered then it will last otherwise JUNK like I said.[/quote]

280!! lol, more like 210. I dont think the GN even made 280..

 

[pontiacgp]

[Well i suggest you remove the factory motor that lacks power and put something in your car that pushes 300 whp which is what he is asking and maybe you will have a different opinion. You will be lucky if a stock motor in any gbody put more than 280 at the motor let alone at the rear. If its stock powered then it will last otherwise JUNK like I said.

I removed my 305 long ago and my 200 r4 and replaced them with a 355 vortec with headers and 2.5 ss exhaust and with a T5 WC...I was running a 7.5 auburn posi with a 3.08 gears and it took two summers before the pinion gears broke and I drive my car hard. Those pinions gears are significantly smaller than the pinion gears in an open carrier so for now I'm running a 7.5 open carrier. I'm changing the rear end this winter to a ford 9" because I don't trust the auburn any longer and to put a locker in with 28 spline axles will cost me more than a 9" set up, plus I want the rear 2-2.5" inches wider so the 7.5 has to go. ....I was going with a 64-67 chevelle 8.2 but they are hard to find and the gears are even harder to find and the 12 bolt is way too much money for what they are worth. I can easily fab the 9" to the width I want and there are lots of gears out there

 

[Bonnewagon]

I ran a 1970 GTO 400 in my Malibu wagon for 10 years with a 7.5 rear with 3:23 gears and S-10 part time posi. Over 300 hp and with a manual trans too. I was not easy on it and never had any trouble. I'm sure I COULD have broken it, but you can break anything if you try hard enough.