Rear end identification

[73Bronc]

Does anyone know how I can identify what type of rear end I have? I'm unable to locate any tag on the housing. There were a few numbers and letters stamped on it but I'm not sure if those are what I need. My right rear axle continues to leak even after I had a new bearing and retainer ring pressed on it last week. This has been a reoccurring issue and I'm starting to wondering if I may be dealing with a different axle. Thanks,Trey

[chuzie]

I have seen a decoder somewhere on the web. Let me do some digging and I will get back with you. What info do you have on the stamp? We at least know it is a 9" right?

[73Bronc]

Here's a photo. I see 'DIF 12' and '2J5' stamped on the housing.

[bucketobolts]

There should be a metal tag under one of the bolts. It will have a code that looks like: 3 L 50. This would be a 3.50 gear, which is most common, and the L is a TracLok diff.

If you can not find a tag, you can tape a piece of string to your drive shaft, place a mark on a tire, roll the truck forward one tire revolution, and then count the wraps of the string on your drive shaft. If is wraps about 3 1/2 times you have 3.50 gears, just a bit over 4 and you most likely have 4.10, and if it wraps 4 1/2 time you'd have 4.56.

Then to tell what diff you have you jack up the rear and put the trans in neutral. Turn one tire and watch the direction the other tire turns. If they turn in the same direction you have a TracLok, Posi, or locker of some sort. If the tires spin in opposite directions or seem to spin independent of each other the diff is open or standard spiders.

[73Bronc]

The tag was not on the housing but I was lucky enough to find it. Here's a picture:



It reads as follows:
WEM - E 2JB
3.50 9 605B

So it appears to be 3.50 gear and I assume the 9 indicates 9"? Any idea what the other items indicate? Thanks,Trey

[73Bronc]

I ran a few Google searches and found several sites that have rear end code information. Here's one such reference:


My tag is coded a bit differently than this one but it gets me a little further. This site also had a table of codes. The WEM-E codes were listed as follows:
WEM-E Bronco '66-'73 3.50 8 3/4 in NL 28 2780 lb Axle
WEM-E2 Bronco '66-'73 3.50 9.0 NL 28 2780 lb. axle
http://www.fordification.com/rearends-ford06.htm

[chuzie]

So according to the site it is a

WEM-E
Bronco '66-'73
3.50
8 3/4 in pinion
NL (don't know what this means)
28 spline
2780 lb Axle

[73Bronc]

Yeah that's correct. I saw a similar thread on classicbroncos and one of the replies stated that the 8 3/4 is also considered 9". Ultimately, I need to determine if my specifications have an impact on the type of bearing I need on the axle. I'm going to drive the bronco this week and see how the new bearing holds up. If I see it leaking again, I'll probably just pull the other axle out and see if the bearing on that side is different in some way.

[chuzie]

I had a similar issue once. It turned out to be the lip inside the housing that the seal rests on. It was preventing me from getting the seal aligned correctly and became cocked (sorry misaligned) when i installed the bearing. I ended up junking the housing because of it.

The cause of the damage may have been me getting to aggressive with the puller.

[blazinchuck]

I was having some serious leaking from mine at the housing and both tubes. I had just installed new seals,bearing...but it still leaked. So, I took everything apart and cleaned it up. I couldn't see anything wrong. But, I put it together with some rtv right around the bearing race(in the tube) hoping that would seal it up better. So far zero leaks! Good luck with yours, there will be plenty of people there to help if anything should go wrong,Chuck