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RocketA
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 Posted: Wed Mar 30, 2022 7:44 pm Post subject: Bearing Housings. What's the difference between early and late? |
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I'm helping a buddy out with a '69 and he's got a bearing race that spins in the housing. We have a guy with a 253 E part with no spin but will it fit the earlier bus?
For my buddy's year we've got 211-501-253 and 211-501-254 and those are good 8/67 up to 7/70. He's got the 253.
But from 8/70 and up there's 211-501-253 B and 211-501-254 B.
Then there's 211-501-253 E and 211-501-254/E also for 8/70 and up.
What's the difference between all these? Are they interchangeable? Or can 8/70 and up not be used on earlier bays? |
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germansupplyscott
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| Posted: Wed Mar 30, 2022 8:28 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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8/70 and up use a different outer bearing. I don't know what the implications would be in using it on an earlier Bus. It might change the distance of the wheel from the centreline.
It's always best practice to replace with the same part. Too high a chance of unforeseen issues otherwise.
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kreemoweet
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Location: Seattle, WA
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| Posted: Wed Mar 30, 2022 9:42 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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The B version was introduced in '71, to use the new outer roller bearing setup. The C version in '72
I think was for the change in brake cylinder mounting: after '71, the bearing housing had a flat for the bolt head and clearance hole, whereas before the bearing housing was threaded to take the bolt.
I've no idea what changes later versions might have had or their compatability with '69 parts.
There also may have been a change in '71 to use 2 10mm bolts and 10mm dowel to mount the brake backing plate.
Unless the bearing housing is really badly worn, you might consider just using some sleeve/bearing
retainer compound on the inner ball bearing outer race (I assume that's what's spinning), instead of all these parts changes. Every well-used bearing housing I've seen has had the roller bearing able to
spin at least a little bit.
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airschooled
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| Posted: Wed Mar 30, 2022 10:51 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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Loctite sleeve retainer compound (green) fills gaps up to .005" for things like this. .003" or larger is generally detectable by hand, or at least rotation, so if it isn't clicking back and forth across the diameter, I would CLEAN the surfaces, slather it according to the instructions, and move on.
Robbie
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Alan Brase
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| Posted: Thu Mar 31, 2022 12:07 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| airschooled wrote: |
Loctite sleeve retainer compound (green) fills gaps up to .005" for things like this. .003" or larger is generally detectable by hand, or at least rotation, so if it isn't clicking back and forth across the diameter, I would CLEAN the surfaces, slather it according to the instructions, and move on.
Robbie |
Unless you have another parts car with exact same parts, Robbie's answer is the best answer. I'd emphasize the cleaning part. Use Loctite cleaner if you can.
Most important to get the big nut tight to spec.
No need to create a mongrel with 2 different years parts on it. I think brake shoes are different too, 68-70; 71-71, 73-79. I think.
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Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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Wildthings
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| Posted: Thu Mar 31, 2022 4:06 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| Bearing systems like the rear Transporter hubs are frequently designed to have the "fixed" race turn slowly in their bore. This allows the wear to be equalized around the race instead of all of the wear occurring in one small area. While locking the race in place may reduce wear on the hub, it may also greatly reduce bearing life, leading to early bearing failure and possibly severe damage to the hub assembly. |
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Alan Brase
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| Posted: Thu Mar 31, 2022 11:01 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| Wildthings wrote: |
| Bearing systems like the rear Transporter hubs are frequently designed to have the "fixed" race turn slowly in their bore. This allows the wear to be equalized around the race instead of all of the wear occurring in one small area. While locking the race in place may reduce wear on the hub, it may also greatly reduce bearing life, leading to early bearing failure and possibly severe damage to the hub assembly. |
Wow, you could be correct!
The crazy thing is, I've been driving these things, T2's from 1982 to 1992, then T3 from 1992 to about 2018 and only a bit after that. And I drove a LOT of miles on some of them. Maybe 600,000 miles, more than half of that being Vanagons.
BUT I have never actually changed a rear axle bearing.
I never found one failed!
So, maybe I should just go look it up in the Bentley or better yet the genuine VW T2 manual that is basically what the Bentley is a copy of . The orange cover one. See what they say? I just figured it was a light press fit, but maybe more a SLIP FIT?
So what do you do if the race has failed so badly it seized or turned blue?
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Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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germansupplyscott
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| Posted: Thu Mar 31, 2022 12:29 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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FYI the late outer bearing is a press fit into the housing - not designed to turn.
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SGKent 
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| Posted: Thu Mar 31, 2022 3:53 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| Quote: |
| So what do you do if the race has failed so badly it seized or turned blue |
If it has turned blue, you replace the parts that are blued. Meaning that if the bearing seizes and turns the hub and the bearing blue, both get replaced. If the bearing went bad and just blued the race but not the hub then replacing the hub might be optional depending how galled it was. If the grease went away and just the roller or ball bearings turned blue then one would replace the bearing which included a new inner and outer race.
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RocketA
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| Posted: Fri Apr 01, 2022 6:39 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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The bearing race I was writing about spins in the housing but there isn't other movement.
I was thinking I'm gonna get some red loctite and a new bearing but if it's supposed to be a spin fitting then why bother? |
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kreemoweet
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| Posted: Fri Apr 01, 2022 9:29 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| RocketA wrote: |
The bearing race I was writing about spins in the housing but there isn't other movement.
I was thinking I'm gonna get some red loctite and a new bearing but if it's supposed to be a spin fitting then why bother? |
Who said it was supposed to spin? That is sheer speculation by some posters here. VW service literature
mentions nothing except using a press to install the bearing. Any bearing that requires a press to install
obviously is not meant to "spin". And the usual red loctite is the wrong
product to use. Loctite makes several compounds specifically for use with bearing/sleeve installation, the clearance
is a major determinant of which one to use.
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busdaddy
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| Posted: Fri Apr 01, 2022 10:09 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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X3 or 4 or 5 on no spinning, if the bearing was designed to spin in the housing the housing would be hardened, or have a pressed in sleeve. The bearing is the consumable, not the housing, it has to remain stationary in the softer component.
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raygreenwood
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| Posted: Fri Apr 01, 2022 12:06 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| busdaddy wrote: |
| X3 or 4 or 5 on no spinning, if the bearing was designed to spin in the housing the housing would be hardened, or have a pressed in sleeve. The bearing is the consumable, not the housing, it has to remain stationary in the softer component. |
Yes....I think the supposition comes from researching the subject. There is a lot of data and application guides for bearings. After this subject came up abut a year ago I decided to dig into it a little bit. I found lots of online bearing guides...spoke to a few automation engineers I know etc.
The online bearing housing guides have language that is ambiguous. You will see language that states "inner shaft press fit - outer race loose fit". What the hell does "loose" mean?....exactly?
Loose as in turning/sliding? or loose as in low tonnage in the press....low number interference fit like 0.0005" to 0.001"?
Digging into that.... asking a few questions and looking at a few applications....
1. "loose" outer race fit ....with THIN races...has been defined as light interference fit...but an interference fit nonetheless. Its not supposed to turn. The reason for a careful, loose fit is because its virtually impossible to get housings perfectly round or keep them that way when they heat up. The object in this case is to prevent the distortion of the outer bearing race.
2. Actual loose and in sometimes rotating like Wildthings suggested. BUT....in almost all cases I could find those bearings were either self aligning roller bearings with crowned rollers ...or used in slower rpm applications where the outer housing that the outer race is pressed into may have a high degree of rotation itself.
An example of this...would be something like a large industrial line with large heavy rollers. The roller bearing and the inner race itself is pressed on tight to the center shaft. The outer race is a loose press fit with no interference.
As the line speed on the roller and drum goes up and down quickly....sometimes the race in the drum can slip and rotate. This is desired in this application.
Why? This is important now:
.....not to equalize wear on the bearing race....but to prevent a quick "flip-flop" of matching of rotational speeds.... where the rollers no longer roll for a split second...but instead SKID across the surface of the race. This totally forces lubricant out for a split second and causes galling and spalling.
LIKEWISE:
.......in an application where the outer housing that holds the outer race....and does not have much rotational movement (like the rear wheel bearing hub) .....if the outer bearing race is allowed to rotate or slip occasionally.....it CAN cause this same time of speed mis-match issue and cause the bearing rollers to SKID for a split second. As this continues....it eventually causes spalling.
Unlike the bus...which I believe has an inner ball bearing for load capacity and an outer roller bearing for alignment (please correct me if I am wrong...I'm not near my books)....my 412 has two identical roller bearings facing toward each other with a spacer and a pre-load setting.
But the overall concept and installation of the outer race is pretty much the same as bus.
The interference fit on the outer races from the factory is LIGHT....exactly to keep the distortion down on the races.
Over the years the available bearing quality became a problem I found that I would have to drive out SKF and FAG bearings wit ha drift and they always have an interference fit going back in.
Then i switched to National and Timken (all that was available)....and they were ~0.00005" to 0.0001" smaller. They could be mostly pressed in with fingers and then tapped lightly with a screwdriver.....but they STILL fit "precisely".
So this was a "dead fit" ....not an interference fit.
The lifespan of these was shit. Roughly 20-30k miles with spalling all over the place. For a year and a half when these bearings were all I could get....they had to be replaced roughly every 3-5 months at the mileage I was driving.
Once I was able to start getting SKF and Timken made in France bearings that had a light interference fit....this problem just evaporated.
It had all the hallmarks that I have read...of roller skidding from the outer race rotating.
This is actually called "bearing creep". From everything I have read and heard....outer race housings that are not locked to the shaft under power....should not be allowed to rotate unless its a self aligning, multi-axis spherical bearing or in some cases a vertical shaft assembly where the weight on the shaft and bearing is very high.
Ray |
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Wildthings
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| Posted: Fri Apr 01, 2022 9:20 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| busdaddy wrote: |
| X3 or 4 or 5 on no spinning, if the bearing was designed to spin in the housing the housing would be hardened, or have a pressed in sleeve. The bearing is the consumable, not the housing, it has to remain stationary in the softer component. |
If you have no movement of the outer bearing race in the hub then the hub assembly will have no way to account for changes in temperature and rapid bearing failure will be the result. This is especially true with ball bearings as for their size they can handle little load. This is on top of all the wear all occurring in a small area of the race. We are not talking about a lot of movement here, just a single rotation of the outer bearing race in the hub every 10,000 +/- rotations of the axle, so the wear is minimal. You will get some rotation of the outer race in the housing even it it is a light press fit.
Think of what happens on the front axle of a rear wheel drive vehicle. In this case it is usually the inner race that is "fixed" in place with the outer race spinning. When you assemble the hub the inner races slip readily onto the axle as there is a clearance fit between both inner races and the axle. I do not understand why people panic over the idea of the "fixed" race not being a tight pressed fit when on the drive axle when it is very common on the front axle of rear wheel drive vehicles.
Do you get a little wear to the hub assembly when the fixed bearing rotates? Yes.
Do you get a lot of bearing wear and destroy the hub assembly when the fixed bearing fails because it can not rotate? Yes. |
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SGKent
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| Posted: Fri Apr 01, 2022 11:01 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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I wonder why then one has to heat the transmission housing to fit in the pinion bearing. It is a roller bearing and it requires a press to get it out if the housing is still good.
I don't see these as "interference fit." I was always taught in machine work that an "interference fit" was usually a one time thing, like pinning something. I'd call them a light interference fit as Ray did, or tight fit.
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Wildthings
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| Posted: Sat Apr 02, 2022 6:52 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| SGKent wrote: |
| I wonder why then one has to heat the transmission housing to fit in the pinion bearing. It is a roller bearing and it requires a press to get it out if the housing is still good. |
You are talking about a relatively large heavily preloaded tapered roller bearing versus a ball bearing or much smaller taper tapered roller bearing that can handle little preload. If you preload a ball bearing as you all are suggesting by locking the bearing shells in place their life will be greatly reduced.
Back in the 1960's if you piggybacked a trailer on a railroad flat car the life of the wheel bearings for the trailer became very short, just a few thousand miles versus a normal life of many hundreds of thousands or even millions of miles, hence one of the reasons shipping containers became popular, no axle bearings to destroy. Today you will see trailers being piggybacked because seamless rail has become the norm and because railroads have a higher standard to meet when it comes to the steel wheels used on cars that are used for piggybacking trailers, all in an effort to minimize the oscillating loads damaging non rotating bearings. If you stand out next to the tracks today you will still hear an occasional bit of noise from the flat spots on the steel wheels beating against the steel rails when most railcars go by, but the special flat cars designed for piggybacking will make little noise in comparison as flat spots are not tolerated by shippers. There may have been other engineering changes to the trailers and the rail cars that carry them as well, but I have not kept up with the issue.
Talking about transmissions it is common on the mainshafts and countershafts to have a ball bearing on one end being held in place by a snap ring. This allows the bearing to maintain its axial position in the case while still being able to turn to equalize wear. The bearing on the opposite end of the shaft may well be designed to float to prevent axial preloading of the weak ball bearing and to allow its own outer race to rotate. |
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busdaddy
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| Posted: Sat Apr 02, 2022 9:58 am Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| Wildthings wrote: |
| busdaddy wrote: |
| X3 or 4 or 5 on no spinning, if the bearing was designed to spin in the housing the housing would be hardened, or have a pressed in sleeve. The bearing is the consumable, not the housing, it has to remain stationary in the softer component. |
If you have no movement of the outer bearing race in the hub then the hub assembly will have no way to account for changes in temperature and rapid bearing failure will be the result. This is especially true with ball bearings as for their size they can handle little load. This is on top of all the wear all occurring in a small area of the race. We are not talking about a lot of movement here, just a single rotation of the outer bearing race in the hub every 10,000 +/- rotations of the axle, so the wear is minimal. You will get some rotation of the outer race in the housing even it it is a light press fit.
Think of what happens on the front axle of a rear wheel drive vehicle. In this case it is usually the inner race that is "fixed" in place with the outer race spinning. When you assemble the hub the inner races slip readily onto the axle as there is a clearance fit between both inner races and the axle. I do not understand why people panic over the idea of the "fixed" race not being a tight pressed fit when on the drive axle when it is very common on the front axle of rear wheel drive vehicles.
Do you get a little wear to the hub assembly when the fixed bearing rotates? Yes.
Do you get a lot of bearing wear and destroy the hub assembly when the fixed bearing fails because it can not rotate? Yes. |
I'm confident I could find multiple manuals for various machines stating that if a bearing is loose in the bore the part is NFG, can you find one that specifies it has to be a loose fit?
Front spindles are hardened, so that comparison to a cast rear housing is like apples to oranges.
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raygreenwood
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| Posted: Sat Apr 02, 2022 1:51 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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Again....to all answers and opinions....depending on the design of the part, weight, pressure and/or torque loading, rotational speeds, temperature, bearing type....and.... whether the part that the outer race is pressed into is "powered" in rotation or whether the inner race on the shaft is powered in rotation...or both........there are some designs that have the inner race on the shaft pressed tight/interference fit with outer race loose.....and some that have the outer race tight and the inner race loose.
Here is a good piece to read. But again....this chart/guide is just the general parameters and also does not specify HOW "tight" or "loose" the fit...because that depends on the metal or material and what temperature and expansion rate.
Take a close look at pages 3, 4 and 5 to start with.
https://www.bearing.co.il/FITS06.pdf
You will note that on page 3, drawing #4 most closely approximates our application. And, it notes that the inner ring...that which the stub axle/shaft is in contact with...is the "loose" fit....usually meaning a dead fit because you have to be able to slide the shaft in. The outer ring it notes...is tight fit....stationary.
Yes...Wildthings is correct that there are some roller bearings that are set up the way he describes....but just as many are not....and I have not seen anything that notes that this was design function for any of the ACVW's. Ray |
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SGKent
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| Posted: Sat Apr 02, 2022 2:10 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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the outer race will not be damaged if it remains stationary. A car or a truck on a train, a race in a non-moving transfer case suffer damage because none of the parts are rotating, so the pressures involved keep going back into the same spot. You do not want the inner or outer race spinning against a surface that was not designed as a bearing surface. It will wear a non hardened hub or spindle. Once that happens the bearing will begin to oscillate and wobble, causing even more vibration.
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Wildthings
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| Posted: Sat Apr 02, 2022 3:20 pm Post subject: Re: Bearing Housings. What's the difference between early and late? |
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| SGKent wrote: |
| the outer race will not be damaged if it remains stationary. |
The wear on a stationary outer race will all occur over about a 90° arc causing the life of the bearing to be shortened by about 75%. Once the bearing fails the hub can be quickly damaged. Since a roller bearing can handle a load many times as high as that of a ball bearing of the same size, having the race turning is not always of particular importance, though in many cases the outer race of a roller bearing is designed to spin as this allows the use of a smaller bearing. |
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