Question on stock axles. I've heard 8.5" 10 bolt axles are the same as the 12 bolt axles, is this true? Follow up to that is how much HP can stock axles take? I think they are 26 spline... It's a general question, but my specific application is a 3,800lb car with a manual transmission, 8.5" 10-bolt GM rear end with stock axles and limited slip carrier. Will see sticky tires occassionally. My axles are specifically from a '77 Cadillac and have the 5x5 bolt pattern for big rims.
Ok, Your info is all not right. 10 bolt 8.5 1970-1987 are 28 spline axles 12 bolt chevy are all 30 spline axles 10 bolt 7.5 from 1975-1988 are 26 spline HP rating. All stock axles were made for daily driven cars. Alot of the older chevy axles were tapered and were pretty weak for any track applications. they would always break right behind the spline and giving the c-clip axle a real BLACK EYE. Manual transmission really have the ability to destroy drive line parts as it will depend on the DRIVER and their ability to control the clutch dumps etc. Obviously you have a Apollo or nova type rear 29 5/8" axle length. We retro fit Chevy 12 bolt Aftermarket alloy axles into the 8.5 rear ends and use a 30 spline posi giving the rear extra strength close to the 12 bolt chevy. Holding well into the 500+hp range Jim J D
THANKS! Mine has to be the 28-spline. I haven't counted them since early 2009, I just knew it was the lower count 8.5". I ditched the stock 7.5" for the 8.5". What's the going rate for a set of axles with 30 splines and associated spider gears assuming I want to keep the carrier I have to keep costs down? Hopefully the disc brakes out back can retain any errant axles if they break..... Now that I'm home I was looking through some pictures, and thought I had a picture of the whole axle, but I'm only finding the top. For what it's worth:
150.00 + for 30 spline spider gears set... and only if you have a aftermarket Eaton unit. There are NO stock 30 side gears for a GM trac lock square tab posi units If your looking to go cheap route go to your local pick apart at any 1990 -1996 Full size car or wagon with a 8.5 and look for the G80 option in to RPO code sticker. That will bolt into your 8.5 housing also. I can tell you MOST are whooped and warn out and require the cone(s) to be machined to get life back. Axles 30 spline to fit your rear with out any mods 229.00 a pair. Jim
Jim is right on the money with his advice... When I went to have a good rear end built I went to him and he helped me out BIG TIME!!! Although most rear ends can be beefed up, going with a 12 bolt Moser rear end was the best option for me. I get TON of advantages over the rear ends that came in our cars! It is a bit of time and $ to make sure any rear is true before you weld it to keep it from spinning tubes. Then you have to work with a used old rear and get all new parts and pay for cleaning and install. For the price of the Moser housing it is GREAT! It costs less $ to do it right the first time. All it needs is the TA cover and it will be ready to go! Thanks Jim (Monzaz):TU: Here is the info about the Moser 12 bolt Moser, just needs the TA cover and it is done: http://www.carcraft.com/techarticles...end/index.html The highlights are: - Built for 1200 HP - 3" housings with 1/4 wall thickness, fully welded to the center section - 4 bolt retention flanges (no c clip) and you can use GM brakes - 33 spline Moser axles - 3.150 OD Ford ball bearings instead of tiny needle bearings - Canadian Buicks often had 12 bolts from factory so it looks correct. - No mods required to fit into my 70 Skylark (stock width). They also sell it in the width for your car!
That is a NICE rear end. If I could have that or another kind of "rear end" it would definitely be a difficult decision.
I like it because it is a bolt in!!!!! Plus it LOOKS like a chevy 12 bolt even though it is an ADAPTATION of one... AND my car came with a chevy 12 bolt in Canada so it looks stock when driving around!!
Still just a 355 cube low compression engine backed by an manually shifted Th400... No wheel tubs or hood scoop to give away the turbos. Sorry to get off topic... Back to rear ends.
I just need 600HP worth of rear end. I won't be making that much so there is some room for comfort. I have the TA cover on mine.
