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Merian
Samba Member
Joined: January 04, 2014
Posts: 5212
Location: Orygun
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 Posted: Wed Sep 16, 2020 3:27 pm Post subject: Re: Needle grease rear wheel bearings? |
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I fear that the general taxis of Vanagon owners to carry spare parts has gone awry in this instance.. 
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tjet 
Samba Member
Joined: June 10, 2014
Posts: 3533
Location: CA & NM
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| Posted: Fri Sep 18, 2020 9:08 am Post subject: Re: Needle grease rear wheel bearings? |
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Spare bearing housing with new bearings & seals - good to go 
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MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17155
Location: Retired South Florida
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| Posted: Thu Nov 19, 2020 8:56 am Post subject: Re: Needle grease rear wheel bearings? |
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Had an owner come by with a noisy vibrating rear wheel bearing. I'm posting here not because I used a needle to to grease it, but to comment on how straightforward replacing or actually repacking the rear wheel bearings are.
Removed the tire and brake drum. Used an impact gun to remove the 45 mm axle nut. Removed the splined drive hub. I unbolted the slave cylinder and the two backing plate securing bolts at the bottom. With a hammer and drift, I was able to knock the backing plate free from the bearing housing and set it aside with the hand brake still connected. Unbolted the outer CV and removed the 4 bolts with a 22mm socket that retains the bearing housing to the trailing arm.
With the bearing housing off, set it in the press and quickly pressed out the stub axle. Removed the inner seal and circlip and pressed the inner bearing out of the hub. I then flipped the housing and pressed the outer bearing with the seal out of the hub. Cleaned all the parts and reassembled with new bearings and seals in the opposite order.
I had no indication that the inner bearing would be damaged pressing the stub axle out. I imagine you could clean and repack the bearings and reuse. There's nothing in the manual that indicates you can't reuse the bearings and based on my experience, I don't see why you couldn't. The bearings and housing are packed with new grease and seals. Should be good for another 100,000 miles. Figure on 2 -3 hours per side.
The time to consider this project is when you have the CV shafts out.
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Sodo
Samba Member
Joined: July 06, 2007
Posts: 9618
Location: Western WA
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| Posted: Wed Apr 19, 2023 10:16 pm Post subject: Re: Needle grease rear wheel bearings? |
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Well all that needle greasing was at 180,000 miles.
Now the bearings have 225,000 and I decided to replace them becuase I THOUGHT.....
That if the bearings have "slop' they might wallow out the housings.
So at 225,000 I'd just better replace them with tight new bearings.
I took them apart and every roller and race that I could see, was 100% perfect inside.
The new bearings "seemed" to be a little looser than the 225k mile bearings.
I did some rudimentary measurements and found that YES, 225k mile bearings are tighter than the new bearings.
So installing new bearings, my rear wheels will be LOOSER, with more slop.
This is .01mm on radius, so .02mm on diameter, ~.001 inch looser.
How much looser it is, is immaterial.
It should be tighter than a 225k mile bearing.
And it will get even looser as the new bearings bed in.
I'm inclined to just put the original (roller) bearings back in.
So in retrospect it's was good to change the grease at 180K miles.
It would have been even better if some crazy PO needle-greased it at ~30k miles, but no PO would do that. 
Tomorrow I'll compare the ball bearings.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb |
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dobryan
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Joined: March 24, 2006
Posts: 16505
Location: Brookeville, MD
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AndyBees
Samba Member
Joined: January 31, 2008
Posts: 2332
Location: Southeast Kentucky
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| Posted: Thu Apr 20, 2023 6:15 am Post subject: Re: Needle grease rear wheel bearings? |
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| dobryan wrote: |
| Yep. Put those OG bearings back in... |
I agree ....
I've never had a rear wheel bearing to go bad. However, I've had two inner front bearings to go bad. And, they provided miles upon miles of warning.
And, ironically, I recently ordered all new bearings, front and back. So, I may find the same results that Sodo found.
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'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003. |
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dobryan
Samba Member
Joined: March 24, 2006
Posts: 16505
Location: Brookeville, MD
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50352
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| Posted: Thu Apr 20, 2023 9:00 am Post subject: Re: Needle grease rear wheel bearings? |
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The rear roller bearing can handle far more load than the ball bearing so for most vehicles will never need to be changed. I wouldn't be surprised if the engineering books showed it had a life expectancy of ten times or more what the ball bearing does. Just compare the size of the rear bearing to the front tapered roller ones to understand how lightly loaded the rear one are in comparison to their size.
I would suspect that the main cause of failure to the rear roller bearing is water damage, so for most changing the seal every 200K miles should give one very good bearing life. |
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Sodo
Samba Member
Joined: July 06, 2007
Posts: 9618
Location: Western WA
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| Posted: Thu Apr 20, 2023 5:18 pm Post subject: Re: Needle grease rear wheel bearings? |
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| Wildthings wrote: |
| The rear roller bearing can handle far more load than the ball bearing so for most vehicles will never need to be changed. |
In Europe they use this van "as a truck", right?
It seems reasonable the rear bearings would be pretty tough.
But hold a Vanagon rear wheel bearing in one hand and a Toyota pickup rear wheel bearing in the other, and you will know what "tough" is.
There's a reason the 3rd world fellers load Toyotas stopping just short of a wheelie.
OK enough small talk.
===============
Can anyone tell me "what happens" when you put a rear hub together with the ball bearing in a 'loose' bore?
I was afraid that if I neglected it too long, that 'bearing looseness' would wallow out my housings, ruining the housings.
I like to drive FAST on long gravel roads, at the speed where the washboards smooth out.
So I took a quiet van apart, to replace the bearings, to preclude ruining the bearing housings this summer.
I bought new bearinsg and seals from Van-Again.com. Ken Wilfy
INA/Schaeffer outer rollers, and FAG inner ballbearings.
But I found that my 225,000 mile VW bearings were actually tighter than NEW INA/Schaeffer (roller) bearings.
Notice the spring clip is allowing diametrical measurement of the slop.
Down to the ten thousandths (if that's what you need).
Here's another pic with digital numbers, just simply showing the new bearing is sloppier than the 225k mile bearing.
Be careful - the caliper method was too upsetting to the Facebook fellers so I'll just make a link for my Samba friends. 
My 225,000 mile inner ball bearings are seemingly just as tight as the brand new FAG ball bearings.
So that has been a dilemma, which bearings to run.
Keep using the old and tight VW bearings?
Or put together a looser hub with the new INA/Schaeffer?
-------------------
OK on to dilemma #2.
I now know.... that my van has the dreaded worn out housing bores (the inner bores, both of them).
So the option to preserve them with prudent maintenance is NLA.
It's not way way sloppy but the bearing does drop to the bottom by gravity.
But the van drove whisper quiet 'yesterday'.
And the bearings (at 225k miles today) are 'perfect'.
So these loose bores have NOT destroyed my (original) VW bearings yet.
So if I just put it back together, with fresh grease and new seals it will likely still be 'whisper quiet' tomorrow, right?
What will happen as it goes bad?
Certainly not abrupt failure, right?
I suspect to get abrupt rear bearing failure you have to ignore loud, howling bearings for a year or two.
But will it possibly STOP getting worse,.... now that the loose bearing bore is greased?
There's the option of LoctiteŽ660 bearing mount compound too.
But what about..... just needle greasing it periodically, until it actually announces some kind of a bearing problem?
Maybe renew the seals periodically too.
What would this rear wheel bearing failure be like?
And how much time do I have to notice it, and fix it?
Ideally fixing it before the next trip.
_________________
'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb |
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