Damaged stub axle and hub splines

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Kossco
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Damaged stub axle and hub splines

Post by Kossco » Mon Sep 20, 2021 1:16 pm

Howdy, daily driving 1980 westy. Changed rear wheel bearings about 2 years/40,000KMS (KILOMETERS... IM CANADIAN :P). Rear hub was removed and new bearings installed on bench. Axle nut was torqued properly, to 360#s on clean lubed threads while chassis was in air and no weight on axle. Havent had any issues since install.

Rear wheel was making some noises. Thought it may have been a wheel bearing failure. Jacked up rear and had large play like a failed bearing. Remove hub cap and see this: https://linksharing.samsungcloud.com/kTzW4KGkhp6j The hub is wiggling on the axle, close inspection actually shows the axle nut has impressed its corners into the edge of the hub face.
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Removed brake backing plate and wheel hub and find stub axle teeth and hub splines quite worn. Stub axle has no movement so bearings appear fine. It was just the hub wiggling on the axle. The axle nut had not moved and the cotter pin was still in place.
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So my question is, what would have caused this to happen. Im going to be installing new (used) axle and hub but want to fix whatever would have caused this. Is it expected to wear over 600,000 kms of its life? Or was there a direct cause for this? I would assume if a bearing was blown, spacer was missing or axle nut backed off, it would allow for enough play to cause movement on the splines leading to wear but this started off nice and tight, hasnt had the axle nut back off and took 40,000 kms to present itself. Thoughts? Im a self taught (we'll, Itinerant air cooled/samba/youtube university) VW mechanic so if I am possibly missing something else, love to hear the opinions too.

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skip
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Re: Damaged stub axle and hub splines

Post by skip » Tue Sep 21, 2021 6:13 pm

360 lbs...sound like too much to me. I don't have a Vanagon, but checked the Bentley for late model
Type 1 (217 lbs) and Type 2 (253 lbs). Did you use a clicker or beam type torque wench?
Complexity is the enemy of reliability.

76 Westfalia
74 Type 181

RinTinTin in Waldorf Astoria 1956

kreemoweet
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Re: Damaged stub axle and hub splines

Post by kreemoweet » Wed Sep 22, 2021 8:08 pm

360 ft-lbs is correct for a Vanagon. But, the axle nut shown does not look like
a Vanagon nut, which have 10 slots. It seems to be a bus rear axle nut.
Are they interchangeable? I dunno, but the smaller size and higher torque with
Vanagon nuts might suggest they are made with a superior sort of metal.

And why is it so damn rusty in there, if hubcaps were used? The splines and threads in
those photos sure are looking awfully dry & dusty, what happened to all the lube?

How about the other parts in that rear axle stack? Were the thick spacer
sleeves used, or the thin ones? What "brand" bearings were used? There are
some I would be reluctant to use in a go-kart.

Kossco
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Re: Damaged stub axle and hub splines

Post by Kossco » Thu Oct 07, 2021 4:09 pm

I dont really think the slots matter much on the axle nut. They are just there for the locking pin no? Its what the Vanagon supplier had in stock.

Rusty because winter rims dont accommodate hubcaps. Canadians need aggressive winter rubber and 14" rims dont have any decent icy rubbers available. Ive never seen the axle splines lubed?? No friction or rotation so no lubed needed.

Stock spacer sleeves, been in the van for 600,000kms. Cant see that being an issue. FAG bearings.

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SlowLane
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Re: Damaged stub axle and hub splines

Post by SlowLane » Tue Oct 12, 2021 1:17 pm

Just for reference, here's a post I made to the Samba on the topic of Vanagon rear wheel bearing replacement. I attached a photo to the post comparing the old original spacer with the upgraded spacers recommended by Bentley. The upgrades have considerably thicker walls.

As you can see from my post, they were pretty expensive even back in 2006. I've had no issues with them since, for whatever that's worth. Up to you to decide if this would be a worthwhile investment for you.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
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Amskeptic
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Re: Damaged stub axle and hub splines

Post by Amskeptic » Fri Oct 22, 2021 9:46 am

SlowLane wrote:
Tue Oct 12, 2021 1:17 pm
Just for reference, here's a post I made to the Samba on the topic of Vanagon rear wheel bearing replacement. I attached a photo to the post comparing the old original spacer with the upgraded spacers recommended by Bentley. The upgrades have considerably thicker walls.

As you can see from my post, they were pretty expensive even back in 2006. I've had no issues with them since, for whatever that's worth. Up to you to decide if this would be a worthwhile investment for you.
I did a rear wheel bearing axle write-up here and a "technical service bulletin" on FB that stresses the following:
VW recommended re-checking the axle nut torque after about 200 miles, especially with new parts.
When you have a loose axle nut/exhaust nut/etc, it is not that the nuts unspool, it is that the clamping force can relax.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 206,865 miles
Naranja - 77 Westy . . . 132,040 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 91 Lexus LS400 . . . 94,225 miles

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