85Irocbuild

I am going to be swapping the rear end from my parts car into my iroc. I had the car on jack stands and turned the rear wheels, and the wheels turned opposite directions. I figured that I had an open differential on the parts car, but I took off the cover to make sure. Now I am not so sure if it is a posi or not. The parts car has the RPO sheet missing, so I can't check that. It also seems that the gear ratio is 3.42.

sofakingdom

iTrader: (1)

That's an Eaton Gov-Bomb, aka Grenade-Lock. Probably came out of a S truck since AFAIK the factory never put those in these cars.

It's not a posi until AFTER tire spin has already begun. It acts like an open diff most of the time, including from a stop. But then when the difference in the RPMs of the axles reaches about 100 RPM, it locks up with a bang, and if you're unlucky, it explodes and sends hot sparking metal shrapnel through the cover and into the gas tank.

I'd suggest not putting that into any vehicle that drives on pavement.

85Irocbuild

So should I pull the Gov-bomb and put in a powertrax? Or second option, I have a stock limited slip differential from an 88 iroc. Would I be able to pull the limited slip differential from the 88 iroc and put it into the 3.42 gear rear end? Thanks.

sofakingdom

iTrader: (1)

Powertrax might be OK; only thing is, you need a regular open carrier to install it in, I don't think it will go into that other.

The stock posi in the 88 IROC will be an Auburn most likely, if it's a 10-bolt. Also not a very high-quality piece, but maybe, if it still works (they're bad about wearing out and can't really be "rebuilt") it might be a choice. It would have to be a 3-series one to work with a 3.42 gear; meaning, the gear in that rear now would have to be 3.23 or higher. If it's 3.08 or lower, won't work.

If it's a 9-bolt then it won't work no matter what. Absolutely NOTHING interchanges, internally, between the 10-bolt and the 9-bolt.

85Irocbuild

So I am not able to remove the Gov-lock and install a powertrax? Since this is all new to me, what would you recommend? Thanks.

sofakingdom

iTrader: (1)

No; the Powertrax will only install in an open carrier.

http://www.summitracing.com/parts/pw...r/applications for example

As far as recommendations:

What's your budget? What's the intended use of the car? What's your own level of mechanical experience? (have you ever rebuilt a motor or auto trans for example?) What specialty tools do you have, applicable to rear ends? (dial indicator, calipers, mic, large sockets, etc.)

Can't recommend anything that would make sense, without knowing that sort of thing.

Those parts aren't cheeeeep. Plus, if you have to pay somebody to do this kind of stuff, the price gets sky-high REAL quick. You could EEEEZILY burn through $1200 buying a carrier, gears, axles, all the bearings, and paying somebody to do it all for you.

85Irocbuild

The car is only going to be a daily driver, so high performance is not whats important to me. I want the LSD mainly for adverse weather conditions. I have a decent level of mechanical experience, but I have never rebuilt a rear end before. I do not have any specialty tools for rear ends. My budget is less than $500.


The main reason I am doing this is because I am trying to put a manual transmission into my 88 iroc, and I am trying to figure out what rear end I need. the 88 has a an automatic with a 2.73 rear end

big gear head

That is the Eaton Governor Lock, and GM did install them in a few F and G body cars, even though they were mostly used in S series trucks. They are not very strong, but if you just have a stock 305 or something like that then it's probably going to be fine, at least for a while. I don't recommend installing them, but if you already have it then you might as well use it until it breaks. Most of the time they just break the little gear on the end of the governor, and then they will no longer lock up at all. In a few extreme cases they will split the case in the center and poke pieces through the cover.

I also wouldn't install an Auburn. If you have the money for something better then go for the Eaton Posi or Yukon Dura Grip. They are very tough, and they can be rebuilt if anything ever did go wrong. A Power Trax is going to cost just about as much as one of these and you probably won't like it very much.