HOW TO: Install rear axle seal kit

[Okie Adam]

Excellent explanation! Thanks for the pics too. Incredibly helpful!
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Oil Capital Air Cooled
55 Wolfsburg Kombi
60 Walkthrough Kombi
62 Single Cab
66 21window
67 so42
76 Westy
64 Karmann Ghia

[thestoneroses]

Leaking RGB seals have plagued me for last three years or so. However...I've now done ~500 miles after fitting new seal kits on both axles a month ago and am relieved to report that on inspection today both drums are bone dry and absolutely no oil has made it to the backing plate or wheel.

I'm indebted to the contributors on this thread for helping me get there. And to help others, below is the detail of my install to compliment those of previous posters. Applies to big-nut RGBs only.

1. Loosened wheel bolts and rear nuts, put her on the stands, remove wheels.

2. Started with this mess:

3. Drained RGBs, remove housings, backing plates, old seal, O-ring, etc and thoroughly degreased and dried everything.

4. Here's the rear seal kit. Items to the left are required, items to the right are categorically NOT needed for big-nut RGB. However tempting those large O-rings may look for that recessed channel in the housing, you DO NOT NEED THEM, so bury them six feet under to resist any urge to fit them.

5. Measured both spacers to ensure no wear, polished them up using 1000 wet n' dry.

That's a makeshift clamp on handheld drill, held in vice.

4. Temporarily removed the spring ring from the seal to prevent any damage to it when pressing the seal into the housing

5. After thoroughly cleaning and drying the housing, smeared a very light coating of Permatex Ultra Black Maximum Oil Resistance RTV Silicone.

7. I've no seal press tool or such here, so I improvised using cutoff bottom of an aerosol can which has reinforced lip and a 36mm (iirc) socket in the bench vice to press the seal home, nicely square and firm.

8. Removed any sealant residue, vital to make sure that drain hole is not impeded.

8. Install the spring ring back into the rear of the seal and insert spacer

9. Tape the thread on the axle stub to prevent any damage to the small O-ring, then push it down the stub using the spacer.

10. Permatex coating on the RGB housing, paper gasket, fit backing plate. Forgot to grab a pic, but its self-explanatory.

11. Permatex on inside of the backing plate, second paper gasket, used cut-off bolts to hold in position as suggested by an earlier poster - great tip.

12. Final coat of Permatex on housing.

13. Place housing into position via the cut-off bolts, screw in the first two fixing bolts, remove cut-off bolts, screw the other two fixings bolts and diagonally torque to spec.

15. Compressed air to ensure that drain hole is still clear.

16. Assemble the innards. New shoes; the old ones were too contaminated.

17. Wheels on, lower to the ground, torque up axle nuts.

18. Left overnight to ensure sealant dried.

19. Next day, back on the stands, remove wheels, fill the RGB with oil ...it's just so much easier to do without wheel in place.

I think this last part is as important as anything: only refill the RGB once the rear nuts have been torqued and not before, else there is risk of some oil seeping through a partial non-torqued seal, once it starts capillary action will ensure it never stops even after full torquing of the nuts.

All in all, job done and so far, so good.

Cheers for your help everyone.
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I can feel the earth begin to move, I hear my needle hit the groove, and spiral through another day.

[Eric&Barb]

Good job! Though the RTV is not need if one polishes/flattens the sealing surfaces of any corrosion/damage, etc.
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In Stereo, Where Available!

[ToolBox]

You should lube the spacer and seal during install so it won't get damaged by running dry.

[thestoneroses]

[Eric&Barb]

[swharris]

Just a big thank you to all who contributed. New to me was the comment about torquing the drum BEFORE filling boxes. Much appreciated!

Just an aside. I thought I had replaced all the seals on this small nut truck when I bought it. I'm almost positive I did. Apparently, I did not pull the large outer spacers. They were really stuck on there and frankly I don't think I even realized they came off as I did it the first time "bareback" without reading up on the procedure and with no manual.

This time I read up and realized they should come off to get to the inner small o-ring. Well, it turns out one of the rings is ORIGINAL to the truck(or had been replaced with OG VW part). This has always impressed me about VW. They even marked the lowly O-ring with their logo. Simply amazing to me. The other amazing thing is how that 59-year-old O-ring had held up compared to an obviously non-VW part(the bottom ring in the 2 shot). The fact companies make stuff out of material that does not last is very frustrating! It's a bit hard to tell, but the last two photos are of the original(next to last) and the off-brand(last). In-person it is very obvious as the aftermarket ring is completely flat on one side, whereas the original marked one is compressed some, but still useable and supple.

[mcmmd]

Hi. I am doing this on my '66 Kombi. I want to paint or powder coat my backing plates before reassembling.

Any advice on if I should tape the mating surfaces where the gaskets meet the RGB and the bearing covers before applying the coating? If the painted surface won't seal as well as the bare metal?

Also I am not going into the RGB but I guess best practice would be to put in new seals in the bearing covers even it the old ones look ok?

Thanks!
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Martin
Austin, TX

[BarryL]

I think the powder coat will be ok if it's not ridiculously thick. You might have to sand the inner diameter where it fits over the outer race of the lower outer bearing.

Yes new seal and small axle o ring.

How are your stub axle outer roller bearings doing?

[mcmmd]

I wasn't having any problem with grinding or play in the rear wheels that seemed abnormal. As I look more carefully at the RGBs, I am wondering if I should go ahead and do the whole job though? The stub axle bearings actually look ok. Here are some photos. I have cleaned the axle up a little but I think you can see that there is some seepage where the axle goes into the RGB.

Can the RGB rebuild be done without pulling the tranny? Looks like a lot easier job if you but I wasn't planning on doing that right now, too much other stuff going on. Also can the RGBs be rebuilt without pulling the axles? I am thinking no because the upper inner bearing needs to be pulled and then pressed back on?

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Martin
Austin, TX

[BonTonRoulet]

I'll make my comments with regard to the 3rd photo above, the left hand reduction box.

Looks to me like there is a line on the axle tube about 1/4" or so inboard of where the axle tube mates up with the inner reduction box housing. Just above the spring plate and forward of your brake line bracket. Almost like the inner reduction box casting has slipped down the tube outwards by the 1/4". Easiest way to tell if this has happened is:

1) Is there a small bolt vertically through the suspension rubber "snubber" bracket into the top of the inner reduction box housing? The inboard of this bracket gets welded to the tube itself, the outer end of the bracket is held in place by a small short bolt into the casting. If the bolt is there and it is threaded into the casting then things might be ok. That would fix the distance of the axle tube into the casting at the proper length.

2) On the backside of the reduction box, just above the spring plate, there is a vertical rectangular boss in the casting of the reduction box housing. This is where a solid roll pin gets driven into the casting to hold the tube. Is the roll pin in place? Originally, when the axle tube was fitted to the reduction box casting, the axle tube was milled through this boss where the roll pin is fitted. It sets the dimension in/out of the tube and cuts into the edge of the tube so that the roll pin holds it all together. It's a very precise fit. And the tube in the reduction box is a very tight fit. In other words, if you drive the roll pin out and use a press to get the axle tube out of the reduction box housing, your chances of putting it back together with things lining up are......slim to none. The axle tube to reduction box casting is so tight that IF your were to heat the casting up to 500F in an oven for an hour then attempt to handle it to get the chilled or room temperature tube in, rotated to the original spot and in/out at the original spot you will have mere seconds of time to get it right to then drive the roll pin back in place before the casting cools enough to make everything too tight to move. Been there, done that, tossed it and found another axle tube/inner reduction box housing that was usable.

Good Luck!

ps: I think you'll find a thread or two on rebuilding the reduction boxes in the "Announcement: Read here first before posting" at the top of the forum for what you are thinking of doing.

[BarryL]

Very accurate stuff that ^^^^. Check out what he said first then maybe try this: https://www.thesamba.com/vw/forum/viewtopic.php?t=361052&highlight=axle+leak
I did this repair over 100,000 miles ago and no leak.

The weep looks tolerable to just keep your eye on it. Does the stub axle have a lot of play up and down? Does it pull in and out excessive? Does it feel smooth when you rotate it in neutral? From my computer it looks like you could get away with just fixing it as is with a new seal, gaskets for the bearing cover and the small o-ring.

[mcmmd]

Gee thanks! I am taken aback by the specificity and detail of your post and very much appreciate it. As soon as I can get to the shop and check of the left side RGB where the small gap appears to be, I will post photos and decide what to do. I am leaning towards going all in but....

If the the axle has slipped what are my options? I don't like the idea of trying to move the axle in the RGB housing! If it has slipped, I guess finding good used replacements is an option? Still trying to make sure I understand the process. I want to be teed up, and ready to go, if I do it.

The bus has about !20k original miles, so it seems reasonable that I could get some more mileage out the the RGBs, it is 55 years old though?!?!

[mcmmd]

Thanks! I will confirm all this and report back. I think you may be right cause on my cursory initial inspection I didn't notice anything to be excessively loose. I just thought since I was "there" go ahead and do it?!?

[mcmmd]

Here of some close ups of the RGBs, fixing bolt and pin are in place and all seems fine. The axles spin freely by hand and there is no grind with the tranny in neutral. There might be the slightest bit more play in the left axle, in and out, than the right, but both seem trivial.

Would it be worth it to spit the housings, inspect and then re-seal with permatex, all new gaskets and seals and leave the bearings if they look good?

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Martin
Austin, TX

[BarryL]

If you are asking me, I would not dive into the RGBs now. If you want to check something out, take the springplate loose from that leaky side and see how the giant freeze plug looks. Use a C-clamp to hold the RGB to the springplate while undoing and redoing the four bolts to keep from damaging their threads.

But don't go by me necessarily. See what others suggest. Few RGB halve joints are as dry and sealed as yours are at that point in their lives.

[mcmmd]

[BarryL]

No. What does the other side look like?

[mcmmd]

Unfortunately I didn't take a photo of it but it is well seated and looks fine. I didn't have time to do much more today, just cleaned everything up and now I am ready to re-install.

I hope to get back at it this weekend. I will post an update asap.

Thanks for the help!
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Martin
Austin, TX

[BulliBill]