8 inch rear axles


Nov 15, 2002
Harrisburg Pa
just added more Horsepower so I have 2 options, Stay with the 8 inch rear and hope for the best or switch to a 9 inch. I have a power trax in the 8 inch and it works great, no spiders to break, but I cant find a company that makes hardened axles for the 8 inch 28 spline axle, I have two 9 inch axles but they need beefed up and im not ready for that yet so who sells 8 inch axles.:shrug:
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Founding Member
Aug 21, 2002
lubbock, texas
..and AFAIK, there are no 31-spline 8"/small bearing 9 axles, so if you want to go that route youd have to step up to the big-bearing 9.

but someone will correct me if Im wrong.

the 69/70 and probably 71-73 cars like the Boss cars and the drag pak cars got 31 spline small bearing 9" rears and i believe some early brono's as well. kinda slim pickins anyway you look at it though.


New Member
Sep 29, 2000
south louisiana
I've got 31 spline late model Mustang sized bearings in my Ranger. These were shipped by mistake and the guy who did the narrowing job was clueless that these were not what I wanted till he was done with the job. The axle ends are small bearing with the Fox/Ranger brake pattern. So yes, you can have 31 spline axles in an 8" rear. I wouldn't recommend it with the trouble I've had with these. There's no room for a thru bolt/nut retention for the bearing, the bolts are fine thread and the threads in the housing are the only thing holding them. Hence they've worked loose several times. The tapered bearing doesn't help either, the retainer plate is constantly under load.