lameusername

Ok, I had 3.73's put in my camaro. (1986 Iroc.) I forgot the spline count so I looked it up so I can find a positrac unit for my car. So I looked up the part number of the gears I bought and it says I have 27 splines??? But when I read here on Thirdgen, it says that I should have 26 splines???? Here's the part number of the 3.73's that were put in GM875373 if it helps. I don't know if it's a typo or if I really have 27 splines or what. Any help would be greatly appreciated.

subroc

iTrader: (2)

Im not sure what it is that you bought exactly. Did you just buy the ring gear and the pinion gear? Or did you buy the whole carrier? I just looked up the part number you gave and came up dry. I will tell you this though that in 1986 you should have a 26 spline 10 bolt. In late 89/early 1990 they went to 28 spline axles.

Honestly if your going to to go through the trouble of putting in a posi you might as well upgrade the axles while your at it. It will still be a somewhat weak rear end at the end of the day but at least it will be a bit stronger. If it were me i would get a set of 28 spline axles off a fellow board member or go aftermarket..and then match them to a 28 spline Eaton posi unit. That way, with new bearings, seals, posi and axles you would have a fairly solid rear as far as 10 bolts go.

lameusername

Yes, I did just buy the ring and pinion. But here's a couple of links that say I have 27 splines. I mean, from what I've read on the net and then hearing from you, I can see
that I should have a 26 spline count but when I see what these 2 websites say it says
otherwise. But if I were to change axles and find a 28spline rear end would it just bolt
on and be compatible with my tranny or would I have to do any mods???

http://motivegear.carshopinc.com/pro.../78847/G875373

http://www.autopartswarehouse.com/de...92G875373.html

jmd

iTrader: (4)

The pinion gear from your 3.73 gearset has 27 splines. And maybe 11 teeth. The 27 splines there did not change over the 10 bolt production and has nothing to do with buying a posi.

The axles in all 88-down 10 bolts are 26 spline. These fit into the side gears of the differential carrier so the posi differential must be 26 spline to fit stock 86 Camaro 10 bolt axles, for example.

89-the 90s, many 10 bolts got 28 spline axles and used a differential carrier with 28 spline side gears. At some point, all 10 bolts got 28 spline axles from the factory.

Yes, you can take 28 spline 1992 Camaro axles and use them in your 86 housing with a 28 spline posi.

JamesC

iTrader: (5)

Info in the link below may prove helpful:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC