Cascade Crew

[Xophertony]

i don't know what ratios 10 bolts come in... but i know i need a ten bolti would like it as close to 3.23 as possible, as that was what originaly came in the car.

[badbob66]

Portland auto wrecking on Colubia Blvd had 1 a couple of weeks ago.
It was on a black 85 trans am,It is next to the big crane they have out in the yard,its a u-pull yard so bring your tools.
I will go out today and see if it is still there.
Bob

[Xophertony]

exelent... i was going to call yards on monday.

one thing i have always been confused on... how can you tell from the outside if its posi? and what the gear ratios are?

[badbob66]

To late,some allready got to it,They got the rotors and calipers and took off the differential cover
Bob

[alloy]

Honestly, with the stock auburn posi unit that came in the 10 bolts, it really doesn't matter if the rear has posi or not. They only seemed to work for a few thousand miles before the went bad. Mine stopped being a "posi" at around 10,000 miles.

Your best bet is to just get the rear you want with the disks and gear ratio, then put an eaton posi in it. There are some other alternatives like a lock rite, but they are pretty harsh for street use. Dropping a posi carrier into a rear is fairly easy if you have a few basic tools (and a dial indicator and a mag base) and the knowledge to do it.

[Xophertony]

i don't have the know how ore those special tools. so other then calipers and new discs and a cover the unit is intact right? i could use the cover from my current unit. i can buy new discs and calipers (probably a good idea anyway)

[badbob66]

Yes the rest of it is still there,the diff cover was still there,they put it in the back of the car,not sure why they took it off
Bob

[alloy]

They probably took the axles out to get the caliper mounting brackets, so that's why the cover was taken off.

The "special" tool (dial indicator with mag base) only costs about $25. It would be easy to talk you through the install of a new posi carrier.

Buying new disks and caliper from a parts store will be expensive. The core charges for the calipers is $75 each. I know, I've checked on it. You may be able to get the calipers new off the net for less than getting them local. Rotors are expensive also, not to mention the mounting brackets. Then there are brake lines, e-brake cables, ect to have to buy.

For my car I'm thinking of buying a 3.42 4th gen rear, and putting a wilwood kit on it for around $700. Would match the kit I made for the front of my car

[Xophertony]

i allready have all the provisions on the car as it originaly had a disk rear on it, and was not "converted" to drum, it just has a drum unit on it. the E-brake does not work because it is set up for disk.

[rjmcgee]

Every disc brake rear I have seen has been posi. I don't know if there is any proof to back that up though. I agree with Dan though, the Auburn unit that comes in these things stock sucks. I have had bad experiances with them myself. Prolly just try and find a good disc brake rear take out and spend the $'s. Maybe a 9 bolt.

[Xophertony]

don't 9bolts have a different spline count on the input side? 26vs28 iirc?

also, in case it helps... the one in my 2.72 works mighty fine. did a little mini powerbrake yesterday. deffinatly TWO rubber spots on the ground. it was awsome i've never done one so effortlessly before.... but it will be a rare instance.... i plan on driving this GTA for a long time.....


also, if i am going to put a posi unit into a rear i mightaswell do it to a disc rear with 3.23s.... right?

[Xophertony]

need filled. no longer "wanted". thanks for the help guys....