Axles, what's the diff.?

[Chris]

So... I now have two 4.11 diffs sitting in my garage. yay.

I also have a pair of 99 automatic rear outback axles. They male type that stick into the diff.

For some reason I wanted to see if I could put those axles into my diff.

Both of my diffs are the female type, so theoretically the axles should work. Or so I thought.

Here's what happens.

Diff #1: The diff I just got today. No idea what it's from, but it has fins on the back cover. The axles do not go in. The spline goes in, but the axle stops short on the thicker shaft after the spline. Looking from the inside the spline never makes it to the spline inside the diff. So that diff appears to have a smaller race. Interesting...

Now lets move on to diff 2:

The diff I got from Dan. It's a 4.11 from an 01? RS.

The axles slide all the way in and click into place. BUT they just spin, they don't turn the spider gears in the diff. It sounds like the spline is barely touching, but it stripped out, which I can tell it isn't. And he wouldn't have given me a junk diff.

What's interesting about that one is, the 4.44 diff from the same outback that those axles are from is currently in Dan's car. And the axles worked just fine...

WTF is going on here guys?

The main reason I'm concerned about this isn't because some random axles don't work in a random diff, it's because I'm going to use said random diff in my 98, which is an automatic, and the rear end is the same as the 99. So I'm worried I'll get to the rear diff and it won't work. That would kind of piss me off.

 

[Nigel Prodrive]

now you have first-hand experience with an old saying about our favorite cars....

"Subies are like legos....except when they ain't!"

first clue to your puzzle: count the splines, they are not the same on all r axles. also count splines in the diffs, same issue.

earlier diffs take axles with snub-nose ends (last ~3/8" at end of axle is chamfered/tapered) while others have just a very slight chamfer on the axle ends....

find axles and diff with matching # of splines and the right end shape and you're good to go.

[[[unless even THOSE don't go together for some unexplained reason

]]]

 

[Chris]

Thanks for the advise Nigel. I'll have to go start counting. And figure out what's in my car and if either diff will work. I want to know that everything will play nice before I start tearing apart for a 5speed swap.

 

[2point5RS_Dan]

The 4.11 I sold you is a 2002 open 4.11 diff from my RS.

When I put my 4.44 FXT gearbox and diff in, I used the FXT axles all around. So I have my NA axles if you need them.

I put your automatic outback 4.44 open diff in with the FXT axles still in the car after driving a few minutes on the FXT LSD diff and hearing it make screaming sounds. If the diff I sold you isn't working, you know I got your back on it.

 

[IBratmanI]

There you go Chris, just grab the axles that match the diff from Dan!! Then you know that they will work together.

 

[Chris]

So I have no way of counting the splines on the axles on my car without pulling an axle out. And since I don't want to take apart the rear suspension or drop the diff... I can't do that. But I did pop the axle out enough to look at the bit before the spline. And measure it. It measures to the same diameter as the spare axles I have. Since the other axles are 99, and my car is 98, good chance they're the same and will not work in either diff. ugh.

The part that won't go into the one diff I have is the part with the angly lines cut into it. These are the 99 axles, but it measures the same diameter as the ones in my car.

Now, knowing I need axles, or a different diff. I'm going to hijack my thread with a transmission question...

Someone couldn't get the roll pins out... Both sides look like this. Roll pin starting to come out with a broken off punch in the other side

So they used a torch and cut the axle in half.... That's one way to do it I guess...

I guess I'll just take the grinder and cut it up until the axle comes off.

Now for the pressing question. Speedo.

This tranny is setup for a cable speedo, after pulling off the plastic nut, look down the hole and I see this

That's the thing the cable goes into, and it spins when I turn the transmission.

How the fark to I get that out so I can put in a digital one? Or does the digital sensor slot into that too?

 

[Nigel Prodrive]

Chris, you have entered the Subie Parts Twilight Zone for sure now. mechanical drive speedos and electronic ones may have some level of compatibility, but not sure how much.

we have put older gearboxes with mech drive speedos into newer chassis rally cars.....and just relied on the rally computer for speed readings cuz we dint want to mess with swapping speedo drives too!

so here is your own personal opportunity to delve into the "things you didn't know you didn't know about Subaru sheet" and contribute to the general advancement of human knowledge about it!

B)

 

[Nigel Prodrive]

the axle in your 1st photo (angle end) is unlikely to really be off a 1999...it's more like a 93-95'ish one.

 

[2point5RS_Dan]

Someone cookieed up bad on those roll pins.

I'll bring my rear end axles when I help you swap this beast. No cost. I can bring the fronts too, but I destroyed one of the CV's on the right side axle....

 

[Chris]

Nigel, I can assure you those axles are from a 99. Dan has the rear end in his car they came off of. At least, they came from a 99 outback with an auto... I'm 100% positive on that, at least.

I know the speedo will be off because of 4.44 to 4.11 FD change, so I'm ready for that. As long as the VSS works, that's all I'm hoping.

Dan, thanks much! That would be awesome. Hopefully some combination will work.

 

[Chris]

So I can't find a whole lot on the net about different axles vs different diffs and whatever.

Nigel since you've seen, and probably broken a lot of axles I don't doubt what you say. but I also know that they came from a 99 legacy, so that leaves me a little bewildered.