I plan on putting a Posi rear instead of Limited slip. I was wondering if anyone knows what I have in there now(my Differencial cover rusted over. and Can't get past grime on pumpkin to see what I have. Its a 1987 Camaro Sport Coupe V6 2.8lt FI with 700-R4 AOD Its limited slip now...

 

IIRC, all V6's come with Open end rear ends.

 

Do you know what gear ratio it it 2.73 3.24 3.42 ect. ect.

 

did you also know that posi is limited slip and limited slip is posi

contrary to popular belief on this board, there is NO difference (well, except for the way the letters are arranged in the names)

 

Yeah I know but most people refer to Limited still one wheel and sometimes 2 and posi as both all the time. Or something like that.

 

well like stated before, you've got a one wheel wonder and can do a one tire burnout all the way up the block. Your gears right now shoudl be 3.42 which are stock for the automatic, if you go posi-limited slip then i'd advise atleast sticking 3.42, maybe taking hte jump to 3.73. Most of the v8's you'll find out there have to be tuned port to have posi, since the majority of v8's w/o TPI will have the same open rear end as u , and with a worse gear combo...hope that helps.

 

This could be TOTALLY wrong, but I read some where that my 87 2.8L has 3.23 gears, can some one tell me if thats true? (It's still stock I know for sure)

 

My 1990 3.1L Camaro has the GU5 : AXLE REAR, 3.23 RATIO rear end. If you have your VIN you can put it into the decoder on the main thirdgen.org page and go to business and find exactly what you've got in your ride!

Would I notice a difference to go to 3.42 gears? I don't believe I could just change the gears and change to posi in my existing rear-end though if I remember correctly..... Otherwise I could buy the SLP Posi unit.

 

'87 V6 f-bodies only came with 3.42 open rears- no matter if they were stick or auto

Limited slip rearends are NEVER equated with open rearends- an open rearend slips period- there is no limited about it.

 

Yeah, anyone that calls an "open" differential as a "limited slip" probably doesn't know what they're talking about. So be careful where you pick up terminology from!

WWasem, yeah, you can use the SLP takeoff no problem; it's meant for 28 spline axleshafts (started mid-to-late '89, but is definately in all 90-up f-bodies). It's the best way to go... certainly the cheapest. Remember my '84 3.73/posi/disc swap, upwards of $600... for $600 I could've bought the posi, 28 spline axleshafts, 3.73 gears, and had them installed professionally.

87Camaro, gear and differential installations can be tricky. There are settings like pinion preload and gear backlash; if these are set wrong, you can destroy your gears in a couple hundred feet of driving. Seems to be common (from thirdgen.org messages) to get charged $200 for a professional install. The key is to find a shop that deals in rear-end work. You don't want to go to Pep Boys or Strauss or Autozone or similar to have this work done.

Alternatively, summitracing.com sells a video, by Richmond, on how to install and set up rear gears. You could probably buy the video and the tools to do it yourself. Usually not much changes are required for "just" installing a posi/limited slip differential, but it doesn't hurt to make sure.

And this would be a great chance to put in new gears. Beware, that gear oil in the axle smells like cat ****.

The numbers specifying the gear ratio of the axle, assuming that the gears weren't changed before you got the car, are stamped on the FRONT of the PASSENGER SIDE axletube. Wire-brush that whole area and you'll find a set of stamped numbers. If they're hard to see, wet your finger and rub it across the numbers. There's a 3 digit code (example would be AA2, not a real code by the way) that corresponds with the gear ratio and differential type. WWasem's idea is much easier. If the RPO code sheet is missing, supposedly you can ask a dealer to print one out for you for free.

 

So, if i wanted to put posi in my car, they only thing i would need is this slp unit?

When it comes to rears, i have no idea.

Aren;t these units like 99 bucks, i like my 3.23's i have now, any more info on this?

 

You will need the SLP unit as well as 28 spline axleshafts. Although from the sounds of TomP our cars already have 28 spline axle shafts???? Because if they do you can simply just go buy the SLP unit and be on your way to installing.

 

You should send them an email ( http://www.slponline.com ) to make sure you don't need a spacer for your gears. Gears can be either series 2 (usually higher) or series 3 (usually lower, like 3.73's). The Torsen take-off posi is a series 3.

 

3.23 and down are series 2, and 3.42 up are series 3, I believe.

My 3.42s will work stock.

Hey, how set in stone is that mid '89 change? GMPartsDirect seems to list a different axle for '88+ and '87 down... I'll have to pull my axles to find out. Probably when I do the rear brakes, and put new bearings in!

 

3.08's and down are II
3.23's and up are I

 

I was close... Maybe it's BOP I was thinking of... meh!

 

ok guys so what woud be my best bet performance wise (disk of course) to work with the set up we were talking about last week for my 91????

https://www.thirdgen.org/techbb2/sho...hreadid=184406