My rear end is going bad, its leaking gear oil pretty bad into passenger rear rim. So Im currently on a search for a rear end that will fit with 3.42 or 3.73 gears. Im not sure if any other cars other than f-body rears will bolt in, I really dont have the money to have to fab something up and make it fit. I was curious as to what cars would have the rear Im looking for, and what RPO codes should I look for to see if it has either of the gears and a posi.

Thanks ahead of time.

 

I know that a V6 with a manual tranny will have 3.42's, but it won't be posi. Any rear end from a 3rd gen will bolt right in.

 

Why not fix what you have? Sounds like you just have a seal that is leaking. I would skip the used posi, they wear out and most aren't rebuildable. What year of car are we talking about? You might be able to pick-up a torsen for 99 dollars from slp. New gears will set you back 150-200 dollars. Add new bearings and you will have a rear-end that is better that it was when your car was new. It all depends on how long you want it to last. A used posi might already be toast, or may last a while then burn-up. The used rear may need bearings within a few months and/or the seals start leaking. If you are making more power than stock, I would really consider not using a stock third-gen posi. The SLP torsen, or powertrax locker(no they aren't loud, mine has been on the street for around 7 years), or any number of aftermarket companies are much better and 'new'. Stock, the early thirdgens could have 3.73 and posi--but those are 20 years old now. More commonly the 3.42's ended up in v6 cars without posi.

 

It's very easy to change the seal. Unfortunately, if the seal is bad, it's usually because the axle bearing is bad; and since the bearing rides directly on the axle, if the bearing is bad, so is the axle.

Don't bother with the "codes". That's the idiotic way to try to buy a rear end. Take the cover off and look at what's inside. You have to do that anyway, to make sure you aren't buying a can of discharged shrapnel; why futz around with the codes too??

No other car's rear end will go into one of these cars. The only one that's close is the 4th gen Camaro & Firebird; and it's nearly 4" longer from wheel flange to wheel flange. It will work perfectly howver if you use 4th gen wheels.

Exactly what kind of car do you have? That will determine what the best and cheapest repair/upgrade path is for you.

 

Didnt even realize I gave none of my cars specs. Its a 90 Camaro RS, so I believe its got the 2.73. It was originally equipped with a 305, but Ive got a 350 Vortec set up now. The motor is pretty much stock, except for intake and carb both Edelbrock performer. I run headers with full 3" exhuast.

Everything else is stock, but Im planning on switching my tranny to a TH350 or maybe just getting a 700r4 from a Vette. But that another issue, I hope this help thanks for the comments. The thing with a used rear I didnt even think about it being burned out good point.

 

Try locating a BW 9-bolt from 1989. They have the best rear brakes and were available with 2:77,3:27 and rare 3:45 and all had Limited slips. The other choice is a 4th gen rear which is 4" wider which I personally do not like on 3rd gen car. Or replace it with a 10-bolt and bulid it up the way you want.

 

Originally posted by RB83L69
It's very easy to change the seal. Unfortunately, if the seal is bad, it's usually because the axle bearing is bad; and since the bearing rides directly on the axle, if the bearing is bad, so is the axle.

A bad seal could indicate a bad bearing and is fairly common. Installing a new bearings isn't difficult (especially if already have it apart to do a seal). If the bearing is bad, inspect the axle for damange. If it shows any damage on the surface, just install a repair bearing. It simply lets the bearing ride on a 'new' undamaged part of the axle--and has a built-in seal.

How about this: Get the SLP torsen for 99 bucks, a set of new 3 series 3.42/3.73(what ever brand you like--me, I like richmonds). Full install kit with all the bearings. Axle bearings are usually extra. If you have a lot of miles on the car, I would just get a pair of repair bearings--they are just as strong as the stock set-up and you would be using a fresh part of the axle. Mine got a pair of the repair bearings when I did it 7 years ago--it was over 100,000 miles and both axles showed some wear. Put it all together and it should be better that it was new. Oh, and 2 quarts of synthetic diff fluid.