Replacing iX transfer case seals

[Dave_G]

I'm doing a swap of the transfer case on my iX, and I thought this would be a good time to replace the shaft seals on the case while it's out of the car. Can the seal replacement be done from the outside, or would I need to disassemble the transfer case?

If I need to disassemble it, what gaskets/seals/etc. should I count on needing to order so I can get it all back together?

[Dave_G]

Well, the question is moot now. Some searching led me to believe that I would need to take the transfer case apart to do the seals. Since I have a fairly strong incentive to get things back together quickly (a rally coming up this weekend), and I know the transfer case is good and isn't currently leaking, I just opted to put it in as is, intact. Everything is mostly back together now, and I should be back on the road tomorrow.

I learned a bunch with this little project. The most annoying part of the whole process was not being able to turn the collar on the rear drive shaft to retract it, which meant I had to drop the rear diff to get the drive shaft out. That part was a pain, but not too difficult.

With winter coming on it'll be great to have AWD again!

Background note: When the seller of an iX swears that the center viscous coupling is good, don't believe it. I didn't believe it when I bought the car, but didn't have a way to test it, and I was just hoping that he was right. He wasn't. But since I knew I had a good transfer case ready to swap in, it wasn't a deal-breaker for me in this case.

[packratbimmer]

The lower front is the most likely to drip and can be done in the car. You should be good to go.

[flyboyx]

Well, the question is moot now. Some searching led me to believe that I would need to take the transfer case apart to do the seals. Since I have a fairly strong incentive to get things back together quickly (a rally coming up this weekend), and I know the transfer case is good and isn't currently leaking, I just opted to put it in as is, intact. Everything is mostly back together now, and I should be back on the road tomorrow.

I learned a bunch with this little project. The most annoying part of the whole process was not being able to turn the collar on the rear drive shaft to retract it, which meant I had to drop the rear diff to get the drive shaft out. That part was a pain, but not too difficult.

With winter coming on it'll be great to have AWD again!

Background note: When the seller of an iX swears that the center viscous coupling is good, don't believe it. I didn't believe it when I bought the car, but didn't have a way to test it, and I was just hoping that he was right. He wasn't. But since I knew I had a good transfer case ready to swap in, it wasn't a deal-breaker for me in this case.

why didn't you have a way to test the xfer case? did you read the stickied thread above?

good that you had a spare. they aren't easy to come by as i'm sure you know.

[Dave_G]

why didn't you have a way to test the xfer case? did you read the stickied thread above?

Yes, I knew about that alternative to the jack test, though I've never actually done it. This was a long-distance purchase of a low-mileage (130K), rust-free car, and the price I bought it for was already good for a car with a bad transfer case. (If had had been a good transfer case, it would have been a complete theft.) So I had already decided to make the purchase regardless of the condition of the transfer case, so testing wouldn't have made any difference. It doesn't always work out that way, but in this case it did.

good that you had a spare. they aren't easy to come by as i'm sure you know.

Ain't that the truth. Now that I have known bad VC sitting in my garage that's a spare, maybe someday I'll get inspired to try to repack the VC with whatever special goop works for that. Somewhere there's a build thread from someone who did that.

[Dave_G]

maybe someday I'll get inspired to try to repack the VC with whatever special goop works for that. Somewhere there's a build thread from someone who did that.

$%^&, wouldn't you know it, that was on e30tech, and it's not available at the Wayback machine.

[ghatid]

$%^&, wouldn't you know it, that was on e30tech, and it's not available at the Wayback machine.

Some people have done it and might still remember how. If you're on the ix enthusiasts facebook thing, there's a dude who has the materials for it.

[Seawolf]

I've never taken one apart but I'd guess the internals look similar to this:

http://www.thesamba.com/vw/forum/viewtopic.php?p=6916420

Though of course the iX VC can't be mechanically disassembled. 'I've heard' that you can use the VW fluid to rebuild an iX VC once you've lathe cut the weld seam open.

The original VC cases are allegedly welded in a vacuum chamber, with the price being charged for them now I wouldn't be surprised if BMW launched them into orbit for some space station jockey to weld during a frigging space walk...

[ghatid]

I only remember pieces of the thread.

The original guy who redid it used 100000cst silicone and mixed it with 60000cst silicone and got something in the ballpark of 80000-85000cst. I have no idea how much to put in.

Then there are 2 seals that you can buy from mcmaster-carr. You can buy 50, but I don't remember which ones, just that the cross-section is a cross and not a circle.

After that it's all about cutting it open on a lathe and then cleaning up the thing, replacing the seals, and then welding it all closed again. I think it needs to be TIG welded, and they suggest placing it in water to keep the seals cool while you're welding.

[Seawolf]

Thx, useful info.

There's a welding specialist near here that have rotary TIG welding facilities, I'll find out what they would charge for the case welding.