7.5 rear in 85 GP problems

[n8dogg]

so my rear diff is pretty much cooked, starting to whine and is getting jerky. I'm assuming I have 26 spline axles? I'm pretty sure most g-body came with them (with some exceptions)
I found a few sets of 3.73's and 3.42's with pois for around 300 complete but they are for 28 spline axles and I'm pretty sure mine are 26.

Would i just have to change the axles to the 28 spline ones to make it work? or am I gonna need a bunch of other stuff. Or would I be better off tring to fine something that fits my axles as is?

thanks

 

[BlacKJesuS]

so my rear diff is pretty much cooked, starting to whine and is getting jerky. I'm assuming I have 26 spline axles? I'm pretty sure most g-body came with them (with some exceptions)
I found a few sets of 3.73's and 3.42's with pois for around 300 complete but they are for 28 spline axles and I'm pretty sure mine are 26.

Would i just have to change the axles to the 28 spline ones to make it work? or am I gonna need a bunch of other stuff. Or would I be better off tring to fine something that fits my axles as is?

thanks

bumping up....i have a 84 and would like to know the exact same thing

 

[84GP455]

X3!..... I have an 84 GP with a 85 Cutlass posi-rearend and i want to change the gears but don't know if it's a 26 spline or 28 spline axle. From what i've read they came with both 26 and 28 splines?

 

[pontiacgp]

the only rear ends I know of with a 28 spline are from a 8.5 GN or from some of the 7 5/8 rear end from an F body

 

[n8dogg]

I've found out that it is a 26 spline axle (pretty much everything but gn's and some 442's) After 1988 gm changed to 28 spline ones
. My orginal question still remains though, can I just change the axles? of is there something in the gears I can change so it will accept the 26 spline axle even with the 28 spline carrier?

 

[monte olrac]

if you have a 28 spline unit then you just need the axles and you're on your way...be sure to get carrier shims ahead of time. the splines must match up so you can't use 28 slpine axles in a 26 spline posi or visea versa

 

[DRIVEN]

I had the same question awhile ago. I did a bunch of searching and reading on this site and came up with this combo. Went to U-Pull-It yard on half off day and pulled a posi carrier from a '89 Camaro. Was a 26 spline but had 2.73 gears. Also pulled the 3.42 gear set with a Gov-Loc (limited slip) from an '89 Blazer. The one from the Blazer was 28 spline. Since I didn't have a way to hold the carrier tight enough to separate the ring gears from the carriers, I just bought both. Total cost was $65. When I got home I separated the parts. I sourced a Mr. Gasket ring gear spacer to be able to use the 3.42s with the 2-series posi from the Camaro. I sold the Gov-Loc last weekend for $100. Now all I need to buy is the install kit (bearings, shims, seals). I priced that at $115. So after all is said and done I will be in it about $150 once I add up all the misc. costs.

 

[n8dogg]

I bought some 3.73's today from one of our junk yard suppliers from work from a astrovan and it came with EVERYTHING! for $100 posi and all, still sealed in the housing!! Sweet deal!!
Now it's a 28 spline axle carrier and mine are 26's so I guess now i need some axles. One problem, where the hell do I find 28 spline axles that will fit my 85 grand prix? I've heard GN ones are 28 spline and will fit. Where would I go ablout getting ones that will fit?

thanks.

 

[n8dogg]

would these work? http://www.cottonsperformance.com/cart.asp
or these : http://store.summitracing.com/partdetai ... toview=sku

It says it fits my gp/most 82-87 g-bodys but I'd rather know for sure before I order because it would be a pain to send them back.

I'm assuming most/all g-bodys have the same length axles? maybe not? I'm not good with diff stuff lol

 

[n8dogg]

bump