I am in the process of replacing the rear brakes on my 74. I decided to pull the rear axle and check the spline count. I am not having any issues at present but I would like to add an aussie locker in the future, so what are the advantages of upgrading the rear axles. Also Here is a picture of the drivers axles with some odd tooling marks, not sure what they are. Your help is apperciated. JP

31 spline axles are bigger in diameter and stronger. Good upgrade. Those marks are from the lathe when they turned the axles.

Thanks Viper, I hoped you would come thru. Jayson

I like pictures so here:

http://www.wildhorses4x4.com/category/bronco_rear_axle

socofn,

I'll be doing the upgrade when I get home and put a locker in the rear end. If I was staying stock or already had a limited slip I would probably just keep the 28 spline axles. What is your intended use for your Bronco - street rig, mild trail, rock crawler? If I was sticking to mild trails and not upgrading the rear end then stock would probably survive for a long time.

Since you pulled the axles check out your bearings and seals, they are cheap enough to replace or at least repack them if they are still in good shape.

Check to see if the locker can be upgraded to 31 spline axles later. Newer Detroit Lockers can be changed, but the one I had was a few years too old to upgrade. That way you could put the axle upgrade off till you "need" them, but get the locker now. If the locker can't be changed, I'd consider changing out now, if you are going to push your truck.

I will be using my EB for mod trail use. I will probably upgrade to the wild horse heavy duty and then find a locker to install. Thanks for the help fellas. JP

With a full locker installed I would recommend upgrading to the 31 spline regardless of use. I broke rear axles on the street with 35s and a locker in my first bronco.

Best to upgrade shafts when you add your locker. It's a worth while upgrade, but no need until you add that locker.

J.D.