So I've always been under the incorrect impression that all male subaru rear axles are the same.

That leaves me with some questions.

I'm doing a MT swap in my legacy, and before I rip stuff apart I want to make sure everything fits. And this is what I've come up against...

 

I currently have two different 4.11 diffs, and a set of spare rear axles (from a 99 obw, but should be the same as my 98 GT)

One diff is from a 2002 RS 5mt, the other one, I have no idea. It has fins on the back cover, and the drain bolt's have a 17mm head instead of the 1/2" drive. But I know it's a 4.11 because I counted teeth.

 

Here's the problem.

Diff #1:

When I put the axle into the RS diff it goes all the way in and clicks into place. But when I spin the axle it doesn't turn the gears, it sounds like the splines are stripped out. It just makes a slight grinding noise, and that's it. Just like they're barely touching, but don't match up. I know nothing is wrong with the axles or that diff.

 

Diff #2:

This is the diff I don't know anything about. I got a transmission and this diff for $150 and was told it was all good... anyway.

The axle doesn't even go all the way in. The part of the shaft with the diagonal groves (see pic) comes up short against the bearing. When I look from the inside (cover off) I can clearly see that the shaft is blatantly too big to fit. (that's what she said )

 

So from this I can assume there are at least three different types of axles/diffs

 

 

Can someone who knows about what's going on here enlighten me on what to look for so I can get a matching diff/axle setup. And just in general because I had no idea there were so many differences!

Thanks

Edited June 25, 201114 yr by 987687

Whatever you do, don't go with a cheap Chinese axle. I did that and regret it. Major vibration. About to change it out with a rebuild Subaru axle.

I know all about cheap axles. But that's not my question...

Anyone with any helpful information??

987687...

Since you know all about cheap axles, I have a question for you. I'm trying to avoid a high cost replacement axle for my 4EAT (97 OBW), so I'm planning a trip to the U-Pull-It junkyard. I don't mind dismantling the CV joint and replacing the boot after repacking, but I don't want to waste my time doing it to a cheap axle. How can I tell the difference between a cheap one and an OEM axle while at the junkyard?

987687...

Since you know all about cheap axles, I have a question for you. I'm trying to avoid a high cost replacement axle for my 4EAT (97 OBW), so I'm planning a trip to the U-Pull-It junkyard. I don't mind dismantling the CV joint and replacing the boot after repacking, but I don't want to waste my time doing it to a cheap axle. How can I tell the difference between a cheap one and an OEM axle while at the junkyard?

 

OEM axles have green cups on them. Thats the way I tell with used axles.

Also a hint, if you get used axles from the junk yard it's almost always cheaper to dismantle them and put a pile of parts on the counter rather than the fully assembled axles... Last time I did that, I got them well under half the price of the whole assembled axles.

 

That's true with a lot of junk yard stuff...

Thanks, I'll have to remember that trick.

Incidentally, I have an OEM axle that had been making some noise (not real bad, and usually only one direction and mostly when cold) before I removed it (outer boot was torn). Do you know what the chances are of that axle being worth cleaning and repacking?

Thanks, I'll have to remember that trick.

Incidentally, I have an OEM axle that had been making some noise (not real bad, and usually only one direction and mostly when cold) before I removed it (outer boot was torn). Do you know what the chances are of that axle being worth cleaning and repacking?

 

As long as it's not full of crap. It's probably fine.

 

Now that this thread has been bumped.... Anyone have any answers to the original question?

I wish I could help you with that original question, but I haven't messed with my rear axles yet. Thanks for your help nonetheless.

I wish I could help you with that original question, but I haven't messed with my rear axles yet. Thanks for your help nonetheless.

 

Unless something rips the boot, or you swap things around, I doubt you ever will have to deal with rear axles. They almost never fail.

Not all OEM EJ axles are green. I have seen black ones, and they were OEM originals

Not all OEM EJ axles are green. I have seen black ones, and they were OEM originals

 

Yes, but in a junk yard they're hard to tell apart from aftermarket ones that are also black.

If you just go for the green ones you're pretty safe.

Funny you should mention that. I swapped out my tranny with one that the seller told me was from a 96 legacy, when in fact, it was out of a 98. Basically, I now have front and rear differentials that don't match. I've been running it in FWD for a few months now. Are you saying that it might be easier to change the tranny than the rear differential, like I was planning on doing?

Also, I tried to "create" a full axle using the outer CV joint from one, and the inner CV and axle from another, but found that the spline gear wasn't the same on both of them (I could not slide the outer CV joint onto the axle). Does that have anything to do with the OEM vs. aftermarket situation that you're aware of?

I don't want to come across rude, but instead of hijacking my thread. Start one for your specific problem. You'll get more response that way.