I've have a question for the gurus of the board...

As well all know Ford used a few different styles of axle bearings on the Ford 9 inch. A Sealed ball bearing, a tapered bearing with race and a large tapered for 3700 pound axles.

Now, on the 2900/300 pound 31 spline axles, are the two bearings interchangeable on the same axle?

Hopefully these links work:

http://www.napaonline.com/MasterPage...e+-+Rear+Wheel

http://www.napaonline.com/MasterPage...g+-+Rear+Wheel

Now what I notice is the INNER DIAMETER of the bearings are slightly different. The sealed bearing at 1.5312 and tapered at 1.563 inches.

I have an extra axle that has the tapered bearing (axle is from early 80s truck) and the meat of the axle where the axle bearing sits is 1.563 on the nose.

Does the sealed bearing fit this axle? Maybe the sealed bearing is a tighter tolerance?

I was under the assumption all 31 spline axles were the same, just the bearings and retainers were different. I could pull the axles out of my 74 F100 (with sealed bearings) and measure, but I figured I would let my keyboard do the walking for the moment.

Josh

 

The sealed ball bearing and the tappered bearings are NOT interchangeable.The axle you have is for the tappered bearing only.
The axle/bearing assy. itself is interchangeable between different axle housings. I've seen both styles in the same housing before.
Because the ID is different by .0318", if you try to put the tappered bearing on a ball bearing shaft it will slide on and off by hand. If you try the same with a ball bearing on a tappered bearing shaft, the inner bearing race will crack (if you can even get it to start on the shaft), probably shatter while being pressed on.