Wheel bearings / Back wheel alignment

[Mike V]

Arvo,

Getting to the party a little late.  I agree, way too much torque (120 Ft-Lb). You should never exceed 35 Ft-Lb on the axle nuts, ever.  I don't doubt there's marks left on the outer races. If you get the wheel hub and outer races cleaned up post some pictures for us.  Get the bearing stack and bits cleaned up also, lightly oil everything to protect them from the elements and take a close look at things.  Look for pitting, discoloring, and brinelling on the rollers and races. The spline picture is hard for me to determine if there's significant damage, obviously they haven't seen grease in quite some time.

I would think new bearings are in order. But I wouldn't dive in and order any new wedding bands until after you get the new bearings and races installed and are able to check the preload.  Get everything cleaned up and organized.  You can order OEM wedding band sizes in increments of 0.10mm.  If you need a different size than what you have I would order the closest step up and hand mill to the required thickness. I no longer use the 0.05mm shims, just my personal preference.  I get preload set with wedding band only. You can decide on your own to use shims or not. If you do I recommend you making a record of how many and what sizes so you can be sure to retrieve all of them the next time you service the stack.  Don't forget to order new grease seals too.

Before we move ahead, have we determined what caused the wobbling?

[Barry]

A 7.05mm wedding band is available so that's approx. 2 thou bigger than your current one. It's not at all unusual for the factory fitted wedding band to be too small and therefore they were set up with too much pre-load on the bearings if the recommended torque was used. I found by experimentation that 2 thou made a huge difference as unless you are lucky it will take you from no pre-load to too much pre-load. Even still it's not hard to do better than the factory as my rear wheel was miles out. (See link below)  I hand cut and finished shims from standard steel shim stock which was laborious but better than waiting days for new parts.

http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1382821010/5#5

[Mike V]

You can order OEM wedding band sizes in increments of 0.10mm.

Thanks for the correction Barry. OEM wedding bands can be had in 0.05mm increments.  And I agree 0.05mm can make a big difference in preload, especially if you are at either end of the threshold.

Even still it's not hard to do better than the factory as my rear wheel was miles out

+1.  Personally I prefer a little lighter preload than the factory spec.

[arvo92]

OK. more pictures on the way to identify finally what has been the issue for me.

I work outside for 12 hours per day, getting back to the house still in the time for daylight is tricky. Luckily today I got back a bit earlier and could get proper shots. I re-sized the pictures as small as possible, hopefully I will not get linched for filling up the server space.

Interesting founds:
Both of the bearing races are shown - both have rubbing marks on them from the bearings. Nothing bad by touching the finger.

Both hats have groovs in them. What could cause this? They are definitely not even by touching with fingers.

One of the bearing was good, the other has serious damage marks on the lower side of the bearing shells. Shown on picture. By turning the bearing it does not rotate totally freely. It crudges and grinds. That one is totally shot. I bet that is my issue for the wheel misalignment/bad sounds.

One of the grease seal springs was gone. I only found a 5mm long piece of it inside the hub.

The wheel shaft splines look as brand new, no marks on them whatsoever.

So my question is - new bearings, new grease seals, a new wedding band 0.05mm thicker so I would not have to order it separately. And new hats?

Thanks for the answers so far. They are a lot of help!

[Mike V]

Arvo, yes replace the top hats.  When ordering them be sure to take measurements of both the right and left and relay the information to the people that are supplying the new parts to you.  The grooves are created from the wipers on the grease seals, and the lack of lubrication.  Apply a thin film of oil or light grease on the shoulders of the top hats when you reassemble things. Obviously that bearing stack and assembly has been neglected for some time.  Looks like water has gotten into the hub.

Those bearings are shot.  The outer races and hub doesn't appear to have any serious damage.  Replace the bearings, top hats, and seals.  You may look into a bearing puller to remove those races.  Even with the steel hub inserts, applying a bit of heat to the hub makes things easier.

I would imagine that bike is happy it found you!

[livingdeadhead]

drift the races out from the other sides , with care! just use a normal size hammer! lol  

[Barry]

7.05mm is the next size up on your existing wedding band spacer but I don't think you can make an assumption about what size is needed until after the new bearings have been fitted. It's a trial and error process which is a pain if it means a delay ordering new parts but that's why I went down the shim route.

Mike V is correct in defending the wedding band only approach as that is the OEM solution. Shim kits were an after market solution aimed at making home set up more convenient. They were never available from BMW and never needed by the dealer who had a box full of wedding bands in all sizes. I have no problem using shims as long as you know they are there. BTW when I said I hand cut my own shims don't imagine the end result is inevitably something dog eared and inconsistent. With some ingenuity using home made abrasive mandrels for the bore and clamping the shim between washers on a mandrel for the diameter, the finished result can be very acceptable. It's laborious but also don't imagine you can just punch them out without producing a lot of distortion. That requires very high quality and expensive equipment.  

[Mike V]

drift the races out from the other sides , with care! just use a normal size hammer! lol  

I wouldn't personally recommend this, just my personal opinion, with all due respect livingdeadhead. You can use any procedure you choose Arvo. But if you damage the interior hub shoulder you'll have other issues to deal with.  If you choose to tap the races out from the opposing side I would recommend using a hardwood dowel or something hard enough to do the job without scarring the hub.  I would also use moderate heat to ease the race extraction.  Some adequate pullers are available that are affordable and suitable for the job.  Here's an example of the tool I've used with great success. YMMV.

  

[Ed Miller]

I have one of those tools, too, Mike.  Man that thing is clever.  Seeing stuff like that makes me wish I were creative instead of just smart.  Mine is from Cycleworks, or what ever the name is of Ed Korn's company.

[Mike V]

Me too Ed.  First thing I said to myself when I used this tool was ... why didn't I think of that?!  Ed Korn's creativeness with his specialized airhead tools that are available through Dan Neiner at Cycle Works is nothing short of miraculous in my opinion. This tool makes the job so quick, safe and easy.

This tool also doubles as a puller for the swingarm bearings.  And the square block you see is cut to the correct size to tap the races into the bore if you choose to use it for that purpose.

[arvo92]

Very clever tool you have there! I would love to have something like that but obviously I have no time getting it this time.

I ordered all the part today and I intend to get these bearings sorted during the weekend if the shipment arrives without problems. I decided I am going for the tapping method this time. I looked online for tools pulling them out but most of them are for round wheel bearings not tapered roller bearings. Therefore they utilise the inner shim of the bearing to pull them out while tapered rollers need something behind races. So I did not find anything suitable for tapered rollers.

Therefore I am heating the wheel up (cooking it next to a outdoor woodburner a bit) and using oakwood stick to knock the races out. Hopefully taken care in the process it should go without problems. I think getting the new races in - I freeze the new bearing race and use old inner bearing to knock the frozen race into heated wheel assembly. The new oil seals can be driven in with old races as well.  
Does it sound good?

I measured old hats as well. Motorworks has only one lenghts available. Mine differed both combined by 0.15mm. So it means the new hats are longer by that so I ordered a new wedding band to compensate that. If that is too small, I can grind the existing wedding band which is 0.15mm thicker down to required spec.

This process seemed to be a total headache a few days back but I think I can handle this now. With all the help I have gotten here and my golden pair of hand I should be invincible!

[Barry]

Wheel bearing pre-load must count as a right of passage to Airhead ownership. It'll be very satisfying to know it's been done right..... then you have the front wheel to do.

[Mike V]

Therefore I am heating the wheel up (cooking it next to a outdoor woodburner a bit) and using oakwood stick to knock the races out. Hopefully taken care in the process it should go without problems. I think getting the new races in - I freeze the new bearing race and use old inner bearing to knock the frozen race into heated wheel assembly. The new oil seals can be driven in with old races as well.Does it sound good?

Arvo, "moderate" heat should be more than adequate, I would say 140° to 160° to remove the outer races. Keep the new bearings mated in pairs, don't mix and match.  I would NOT recommend using the old rollers to tap the new races in. You could very easily damage the outer races that way.  Freeze the new race and moderately heat the wheel, then use a socket with an outside diameter that will fit just inside the wheel hub diameter and carefully tap the outer race home. The grease seals can be installed the same way.

Here's a picture for reference below...

I measured old hats as well. Motorworks has only one lenghts available. Mine differed both combined by 0.15mm. So it means the new hats are longer by that so I ordered a new wedding band to compensate that. If that is too small, I can grind the existing wedding band which is 0.15mm thicker down to required spec.  

The top hats will have no effect on determining the correct wedding band thickness during the preload process, the top hats are captured outside each end of the bearing stack, even though they are an essential piece of the entire puzzle.  But they will effect wheel offset. Keep an eye on which top hat goes on which side if they are different lengths.

[livingdeadhead]

mild steel drift , ensure its on the race , not a lip or anything you can damage ! go from side to side gradually tap it out , takes about 5 mins including drinking a pot of tea! i've done hundreds in my own shop and working for other bike shops , the only cock up i've seen is when a friend drifted out the bearings of and old zx10 wheel , didn't look and took fingernail size chunks out of the retaining flange ! even with the chunks missing he refitted new bearings , there was enough meat left for adequate support, about a year later i bought the bike refurbed it and only noticed the damage when i had the wheels enamelled ! yes i refited them and ran it for 1000s of miles , daft speeds too .

[Julio A.]

I had this exact same problem two or three years ago. The wheel would scrape the final drive, wheel overheated and eventually the bearing self destructed and seized the wheel.

Culprit was too thin of a wedding band and too much torque on the axle.

Mike V. was kind enough to walk me through the whole process. It was harder for me to understand the mechanical principle behind the design than understanding integral calculus, but once I got it, the design is elegantly simple.  

I used a steel rod roughly a little larger than the size of the axle to slowly hammer the bearing races out. I then used a suitable socket wrench bit to install the new ones in place. Same goes for the oil seal.
I never used heat, but I did chill the bearings in the fridge.