I know GM went from 26 to 28 spline axles and carriers in 1989 and 1990.

But, will a 7.5 inch, 26 spline carrier from a late 70's G Body (Cutlass, Monte, Elky etc) work in a 1986 Firebird?

Any other vehicles come with something like that? I am doing some salvage yard shopping, just want to know what all I should be looking at.

I know to avoid the Gov Loc. Were there any S-10's or Blazers that had a "real" posi, or were all of them Gov Loc?

Thanks!

Matt

 

i believe that any 7.5" carrier will fit into and 7.5" housing, but there is also a 7.625 carrier that was used in these cars as well so be careful

 

What all is different between the 7.5 and 7.625? This is the measure of the ring gear, correct? Will a 7.625 carrier fit into a 7.5 housing and vise versa?

I have a Richmond Gear ring and pinion for a series 2, 7.5 or 7.652 carrier. I am trying to find a junkyard posi to match the ring and pinion.

I guess my question is can this be done and what kind of problems should I expect to run into doing this?

 

As long as the gears match the carrier series and you use the correct spline count for the axles, then yes a carrier from any other 7.5/7.625 diff will fit into your 7.5 housing.

 

I thought those late '70s cars used 8.5" 10 bolts. Be sure it's a 7.5". Also, would those cars have even had a posi??

4th gen posi's work, but you'd need new axles with 28 splines.

 

the ring gear will fit on either carrier . i know that the inside, where the posi or spiders gears fit are different sizes between the two, but as for the overall size, bearing to bearing, im not sure

 

Lots of gear dealers advertise 7.5 and 7.625 for "all GM vehicles 1977 and up". I would have guessed something came with a similar rear. I don't know though.


How can I identify a 7.5 inch carrier from a 7.625 carrier?

Thanks for all the help, thus far!

 

Thats not true... I know for a fact that the Camaro/Firebird used the 8.5" 10-bolt up to the 1981 model year. '82+ went to the 7.5/7.625

 

Right. Obviously not ALL GM rears from 1977 on up were 7.5 or 7.625. But the gears they are selling will fit a > 1977, 7.5 or 7.625 inch, 10 bolt rear end.

 

There's an important part of that, that comes after that part, and got left out:

...." that use the 7.5/7.625" rear".

You don't have to worry about which carrier it is unless you're trying to put a Powertrax or similar into it; they're all the same on the outside (i.e. they all fit the same into all housings). You DO however have to worry about getting a 26-spline (88-back) or 28 spline (90-up) one, as appropriate for the rear you have.