jayman350

ok so even though i just replaced my rear end about 4 months ago with a used one........ its broken

there's a hole in the differential and it sounds like teeth are missing

right now I'm looking at a couple of options
1. rebuild the rear w/ same gear ratio and no posi
2. get another rear end and just swap it in
3. rebuild the rear w/ same gear ratio but change to posi


I've been looking around at how much gears are gonna run me, anyone have a brand they like? what about suggestions as far as what i have to do to make it posi? should i just get a posi carrier from another f-bod and drop it in?

I'm very new to doing anything w/ rear ends so any advice is welcome..... with the exception of just buying a 12 bolt cause I want to keep this as inexpensive as possible

TheGreatJ

One question Jay: is it a 9-bolt or a 10-bolt rear? You can tell by just counting the diff cover bolts.

I'm guessing it's a 10-bolt since the 9-bolt rears are tougher and take some effort to break. If so, what year? Earlier 10-bolts using the 26 spline design are weaker...you can gain some strength by updating to the 28-spline design. This requires new axles (not too pricey) and a posi unit (convenient that you wanted one anyway.) Gears for the 10-bolt run between $100 and $200 and an SLP posi is about $100. You can also get a used rear for $100-300 depending on what gear it is and what brakes are on it (if any.) You can even use a 4th gen rear, but your back tires are gonna stick out about 2".

If it's a 9-bolt your best bet is going to be just swapping the whole rear. Gearsets alone for the 9-bolt are like $300-350 and that's how much I paid for my complete 3.70 posi/disc rear, brakes and all (plus shipping, of course.)

jayman350

thanks J

its a 10 bolt out of an 85 so it has the 26 spline axles.

I've been searching around ebay and have found a bunch of posi units for the 28 spline axles so I think I'll switch over to that, where can I find replacement axles?

I was just on SLP's website and they have the:
p/n 65002
Differential, Heavy-Duty Zexel-Torsen Camaro/Firebird $499.95

is there another one out there for cheaper?

SLO SS K2

From what I've heard, it is VERY hard to properly install-rebuild a rear end if you are not an expert. If money is tight find a used one.
Good luck,
SPK

Black6SpdTA

I dont have the p/n but it's the same thing, not Heavy-Duty for 99.95.
-Rippin

TheGreatJ

The SLP take-off posi (the ones they pull out of the Z28's to replace with Zexel-Torsen units when building SS cars) sells for right at $100. It's not the Z-T unit though, it's a regular clutch-type limited slip just like you'd find in a stock 4th gen Z28 rear. They may not list take-off parts on their website, try emaiing them.

You can get 28-spline axles through Jeg's or Summit.

Also you defintely do want to have the gears proffessionally set up, but you're better off buying the parts yourself than letting the shop order them and add a service fee. You can also do things like putting in the axle bearings and seals yourself...that'll save you a few bucks.

jayman350

cool, thanks for the info

I know a few mechanics that I'm sure would be willing to do me a favor for a few bucks and a case of beer

TheGreatJ

Just make sure they're experienced with setting up gears. If you do it wrong they'll tear up quick.

12Second3rdgen

Those who have done rearend work before know that its not that hard at all to install gears and posi. A friend and I did my rearend and it has held up to numerous 12 and 13 second passes, 1.8 60 foots and a few passes on Mickey Thompson ET Drags.

cd520

I have a 90 Camaro so I already had 28 spline axles. I bought the $99 SLP Zexel-Torsen take off and 3.42 gears. Works great. BTW, the Zexel take off is not a clutch type posi. You do not have to use a friction modifier in the fluid, though some people do saying it makes it quieter. I've never heard any noise from mine.

TheGreatJ

I was under the impression that SLP removed the clutch-type unit to put in a Zexel-Torsen diff. Why would they take out a Zexel posi? I KNOW they didn't put in lockers or spools...and it would be pointless to "downgrade" to a clutch-type unit.

I'm a bit confused here.....

cd520

This is the SLP Zexel Torsen takeoff. . To tell you the truth I'm not sure what they put in its place. Possibly the heavy duty Zexel but I'm not sure.

jayman350

thanks for the link cd520



what is the friction modifier that you are talking about, is that the posi additive that everyone talks about?

TheGreatJ

Same thing. Basically it's to extend the life of the posi clutches and help quiet the gears a bit. It comes in a little bottle (4oz I think) and you just pour the whole bottle in when you fill the diff.

lordmetalz28

well i have good and bad news for you the bad news is your in for a complete headache with the rears for camaros. bottom line they suck. and the good news is that i just saved a bunch of my on my car insurance by switching to gieco