WHAT AXLE IS IN MY EB

[jmms]

What axles is in the rear of my 1972 Bronco? I know it's a 9" but is it a small bearing or big bearing, 28 or 31 spline?

 

[Gummi Bear]

[quote author=jmms link=board=5;threadid=20578;start=0#msg158493 date=1059519455]
What axles is in the rear of my 1972 Bronco? I know it's a 9" but is it a small bearing or big bearing, 28 or 31 spline?
[/quote]

Look at the nameplate in the glovebox, and post the axle code shown there. Most likely it is a 28 spline (most, if not all, were) and a small bearing. I can't remember which year it was that they switched to big bearing, but I think it was the last 2 or 3 years of production (there were a few big bearings mixed in other production years though, these are funny that way)

 

[77BroncoWag]

???looks like 28 from here ;D

 

[flint_knapper]

Big bearing axle tubes flare out near the end to accommodate the large bearings. Small bearing tubes are straight.

 

[DeanW]

I've wondered this myself. I haven't looked at the tag on the axle; but, according to the info on the glovebox door I have the 4950(?)GVW axle, 3.50 gears, limited slip ('73). Is this BB? 28 or 31?

I'm pretty sure none of the PO changed the rear.

Dean

 

[saddlebronc]

4950 GVW ?

BB rear axles are rated at 3300
Look in the links section. There's a page ( N8's ) with good specs concerning axles.
Can't tell you about splines.

http://www.wsu.edu:8080/~i6735189/diagrams.htm

 

[Rustytruck]

4950 gvw would require the big bearing axle and they would be 28 spline. Providing they didn't change the rear end. another quick way to check would be to measure the bolts comming through the back of the backing plates 1/2" bolts are big bearing axles 3/8" bolts small bearing axles.

 

[Southerner]

If you have the axle out, just count the splines. Of course if you don't I couldn't tell you how to tell, though I agree with others it is most likely a 28 spline. I've got a 71 that is 28 spline. Big bearing vs small bearing, one of the eb parts suppliers has a schematic on their site that has the bearing plate measurements for both. I'll try to find it and post.

 

[Southerner]

[quote author=Southerner link=board=5;threadid=20578;start=0#msg159035 date=1060093735]
If you have the axle out, just count the splines. Of course if you don't I couldn't tell you how to tell, though I agree with others it is most likely a 28 spline. I've got a 71 that is 28 spline. Big bearing vs small bearing, one of the eb parts suppliers has a schematic on their site that has the bearing plate measurements for both. I'll try to find it and post.
[/quote]

It's on this page, hope it helps

http://www.wildhorses4x4.com/18.asp