axle swap

[johnnieb]

I picked up a eaton detroit suregrip for an amazing price, it is for a 8.5 or 8.6 30 spline. I'm not sure if my axle shafts are 28 or 30 without removing them, Question is:; does any body know what make and part number I would need to replace the 28 spline axle to 30 if need be. Thanks

 

[johnnieb]

I also read that you can put 30 spline 12 bolt axles into a 10 bolt 8.5 with a 30 spline carrier. Anyone ?

 

[1low4x4]

I also read that you can put 30 spline 12 bolt axles into a 10 bolt 8.5 with a 30 spline carrier. Anyone ?

I don't think so

 

[HotRodPC]

I also read that you can put 30 spline 12 bolt axles into a 10 bolt 8.5 with a 30 spline carrier. Anyone ?

I'm almost certain the axle bearings are different. I do not recall the type of sure grip but, is it possible that you can change the parts in the sure grip to accept the 28 spline axles? Sometimes it's as easy as swapping spider gears. I just don't recall what the splines go into on a Sure Grip, worth checking into though.

 

[johnnieb]

Here is a quote I was referring to; seems pretty strait forward.

I have been sitting on this info for while and have only seen a hint of it in the truck sections.

We all know the GM 8.5 corp diff.vers the 8.875 and 8.2
Did you know that the 8.5 pinion is the same physical size as the 12 bolt pinion?

But what is not be known is that the lenth and diamiter of the axles for a givin car are the same within a 1/16" or less (in lenth) for a givin rear. In other words lets take a 1972 Nova, It could have came with a 12 or 10 bolt rear. 12 bolt axles have 30 splines, 10 bolt have 28, but yet both axles are the same lenth and diameter.

That means that if the 10 bolt had a 30 spline carrier the 12 bolt axles would bolt in. Now the trick. use a 1990 up gm pickup 10 bolt carrier it has 30 splines and bolts into the 72 nova housing with adapter bearings.

This is what I did, I ordered a 30 spline Truetrac for the 90 up Pickup and the adapter bearings from DTS. Then I ordered some Moser "C" clip replacement axles for a 1969 Camaro (easier) 12 bolt with moser "C" clip eliminators.

These parts all bolted in to my Stock 1972 Nova housing and I topped it off with a LPW cover just for that added Grunt. It has now been in the car and running for over 1000 miles and is SWEET. I fear no axle breakage or c clip loss.

Just for added grins I installes 1/2" 20 X3 screw in wheel studs topped off with the 79 Trans AM rear disk brake set up and it was all done in my little 2 car garage.

I have pics but are too large to post. So I will email them to any one who wants them.

This also applies to 68/72 chevelles (must to use the 72 8.5 diff for 71 and back), and 70/81 Camaro/Firebird . I don't remember the year split for the Camaro.

 

[HotRodPC]

Some interesting info there. Alot to follow and sort out. If I ever feel the need, I'll have to revisit that.

So all of that is referring to passenger car 10 and 12 bolts though right? Cuz there is a difference in passenger car and truck 10 and 12 bolt rear differential systems.

 

[johnnieb]

My Local gear and drive line service confirmed: any truck 12 bolt 30 spline shaft will work, just need different carrier bearings, I also have done a lot of research on the length and confirmed that you can get 30 spline axles the exact length 87-91 10 bolt 8.5 31 5/16 (.313) or 70-81 12 bolt 31 9/32 (.281) that is only 1/32 diff. Doorman actually put's the whole Kit together for around 150 bucks per axle. Not sure I would go with their axles though.

What I have seen is: there is a lot of variation of length depending on the manufacturer , for instance Yukon axles for the same application are listed as 31 7/16. (1/8th " per axle) That"s a little to long imo to work with my Detroit because of the puck that goes between the shafts to hold them out.