Front wheel bearings replacement

[Jschara]

Not having much luck finding info on wheel bearing replacement by doing a search.

I have a 1979 R65 that I just had the rim straightened and was informed that I should replace the wheel bearings.

Any information on how to do would be greatly appreciated.

Jim

[Barry]

To avoid confusion the first thing is to completely ignore anything you read about removing the whole bearing stack which is not applicable to R65's with snowflake wheels.

All you need to do is remove the seals and the inner races will fall out together with a wedding ring spacer and possibly a shim. The outer races can be removed with a bearing puller after heating the wheel to 80 Deg C.  Also heat before pressing in the new outer races. 

With new bearings installed you will have to check the bearing pre-load to determine if a different thickness of wedding band spacer or shim is required. A search on bearing pre-load should find you lots of information on the alternative methods for doing that.

Lastly don't take someone else's word on the bearings needing to be replaced. Remove the inner races, clean everything up and inspect for yourself.  Dried out grease can sometimes be interpreted as a bearing needing replacement.

[Jschara]

Thanks Barry,

I will take your advice and proceed.

Jim

[Jschara]

Now I'm confused.  The seals on my rims are metal with no space to get anything in between the seal and the rim.  I'm afraid to get to aggressive with a screw driver because of damaging the rim.  The gap in the photo looks a lot larger than it is.

Any suggestions?

[wilcom]

Now   I'm afraid to get to aggressive with a screw driver because of damaging the rim. 

Any suggestions?

Stop, don't pry on it. I'm sure someone with great expertise(not me)will come along and set you straight. These Beemers seem to like HEAT in all the right places before bearings and such will drop into your hand

[BPT]

If you're talking about just the seals, they should slide or pop out. To get them in they take some tapping but not any heavy duty pounding.  Maybe there's some dried gunk? 
Instead of prying from the sides, try through the middle. If you don't have any kind of proper puller, you can try something L-shaped, like an allen wrench (maybe spray something around the edges to loosen the gunk).
For the bearing races I had to use a bearing puller and it took some oomph.

[Tony Smith]

In addition to all the good stuff already said, I'll add thhat if you do decide to chage the bearings, a clever move is to replace with the same brand that you find fitted - in my expereince when replacing like with like you rarely need to adjust the "wedding band".

Also, the tension on the bearings is not an "absolute", I would only ever change the weddign band if I could not achieve coorrect preload on the bearings. The right hand holding your axle wrench is the final arbiter of the bearing preload. Do so wisely

[BPT]

Tony - do you have any tips or tricks for getting preload set?   I asked a while back and read up on it and I'm not sure if I've got it it right or not.  After a fiasco of getting tires/tubes installed I need to look at it again.
When I did it last time I ended with "Well, I hope that's right....." and crossed my fingers.

Any easy to understand hints?

[Barry]

If you dont have the correct tool to remove the seals then a very good substitute is an open ended spanner. Pop the top hats out, drop a large washer in for something to lever against and then try different sizes of open ended spanner until you find one that works nicely as a lever under the seal rim. They will come out with no damage.

For pre-load I use the Duane Ausherman shake the wheel method. I suspect that's what Tony is referring to.  https://w6rec.com/the-5-wheel-bearings/  This method works fine and if my bike is anything to go by, you would be very hard put to do it worse than the factory. 

[Tony Smith]

I use a modified version of Snowbum's "shake the wheel" method.

Using all the good info you already have - remove the old out races - use the old ones to drive the new ones in. It's nice to have the proper tools for dealing with bearings, but most home mechanics (justifyably) baulk at the price. BUT, check ebay, Banggood, aliexpress etc as the same tools are available at fractional cost.

Grease the new bearings thoroughly - there are Youtube videos on how to do this and it is important.

Making sure all the internal spacers, wedding bands etc are in place, put the new bearings into the wheel, followed by seals, spacers etc. Do not omit a generous swipe of grease on the outer races.

Making sure not to move the wheel, tighten the axle nut to around 30ft/lb, chances are you will see/feel the outer races seat properly. It is important that you do not try to rotate the wheel while doing this as that would risk damaging the bearings, but applying a little pressure whilst they remain still is unlikely to do so.

Loosen the axle nut.

Spin the wheel and then stop and "shake" it to feel for movement in the bearings - if there is none, loosen the axle nit more.

Once you have some movement, steadily tighten the axle nut, stopping each increment to spin and shake the wheel - do so until all movement is JUST eliminated.

At this point, providing that the lubrication didn't get contaminated, those bearings would probably do several trips to the moon and back.

But, your muscle memory will tell to how much torque was on the axle nut - if it was an amount that leaves you with a concern that the nut might undo - apply a little more torque (say 1/4 of a turn) and use some Loctite.

The bearings will now probably only last one trip to the moon and back because they are technically over-tensioned, but I wouldn't worry too much. BMW makes a meal of chronically overtightening everything these days.

Ok, what if no amount of torque on the axle nut eliminated all bearing movement. Well then you are going to be grinding your wedding band (or buying a narrower one if your LBS has such things).

If grinding your own, remember that a little is a lot and try to take metal off on about .010 in increments - that is a joke, without an investment in machine tools and measuring equipment you cannot be that accurate - I would carefully clamp the band in a vice and give it a wipe with a bastard file until the nice new shiny metal was visible all round the band.

Put it all back together and as soon as you have removed enough material from the band to allow setting up of reasonable preload - stop.


More sensible bikes use roller bearings in wheels - they will not last as long but the new bearings in my K100 wheel took me all of 10 minutes to fit.

A hot air gun is your best friend for pre-heating wheels, just as quick as a torch without all those nasty naked flame risks.

[Jschara]

Thanks for all the input.  But I'm still missing something here.
BPT I can't get anything under the seal because of the (Max BMW parts fiche # 6) pipe as shown in the pic I took of the rim.  In order to use a puller the pipe has to come out first.  Knock it out? Until Then I won't be able to use the info on removing the races, bearings and continue on to pre-load.

Sorry for seeming so dense.

[BPT]

Thanks guys. I'd used Barry's link previouslý but wasn't confident that I'd done it correctly.  I'm going to try it again and I'll use Tony's details and maybe that'll give me a better idea if I'm going in the right direction.

Thanks

[BPT]

Jschara - the pipe that you're talking about shouldn't be in your way.  Could #3 be what you're seeing? It will be sticking through the seal and this is what Barry is referring to as the "top hat". They will actually pull right through the seals pretty easily if there's enough grease in there.
The seals themselves are just rubber donuts (I think there might be some metal inside) and if they aren't coming out easily, it's just gunk holding them in. By that I mean that the only reason people recommend using a tool for removal is so you don't destroy them and you can use them again, not because it's needed to pull them out because of a tight fit.
Make sense?
Once you get the seals out, pay attention to all the other pieces in the middle and you'll probably want to lay it all out in order, take a photo, and then you'll know how it goes back together.  Make sure nothing drops and pay attention for shims that might be hidden in the grease.

[Barry]

If grinding your own, remember that a little is a lot and try to take metal off on about .010 in increments - that is a joke, without an investment in machine tools and measuring equipment you cannot be that accurate

Tony,   Did you mean .010 mm  ?

.010" is a huge amount in terms of bearing pre-load.  The original wedding band spacers were available in .05mm (.002")  increments and I found that increment too big to do the job properly.  I think the wedding bands are no longer available so grinding them down is an option if too big, but if too small then you have to find shims somewhere or make your own which is what I did.

[Bob_Roller]

I got this blind hole bearing puller set from Harbor Freight about 10 years ago .

https://www.harborfreight.com/slide-hammer-and-bearing-puller-set-5-pc-62601.html

Price then was $28US not sure it's worth the price now or not .

It does work for wheel bearing seal removal on our R65's .