Front Wheel Bearings

[roy]

Hi all, I need to replace the wheel bearings on my 85 RT and the manuals all say that you need a special bearing puller to remove these bearings. I searched the Tech pages and did not see any articles on this subject.

1) Do I need a special puller for this?

2) Can I improvise without damaging the rim.


Thanks

[cjack]

Hi all, I need to replace the wheel bearings on my 85 RT and the manuals all say that you need a special bearing puller to remove these bearings. I searched the Tech pages and did not see any articles on this subject.

1) Do I need a special puller for this?

2) Can I improvise without damaging the rim.
Thanks

I think their puller grabs the bearing from the center of the inside race and pulls against the wheel hub. However you pull it, use plenty of heat. At least 200 degrees F on the hub. Same when installng, freeze the bearing and heat the hub.

[deilenberger]

Hi all, I need to replace the wheel bearings on my 85 RT and the manuals all say that you need a special bearing puller to remove these bearings. I searched the Tech pages and did not see any articles on this subject.

1) Do I need a special puller for this?
Yes - a Kukko puller to be exact..

http://tools.baumtools.com/kukko.jsp

http://tools.baumtools.com/pdf/06.pdf (you want the screw type - and use small bits of aluminum under where the legs hit the hub to prevent marring the rim..)



2) Can I improvise without damaging the rim.
I wouldn't try and I've done it a number of times..


Thanks
This is a case where it might be to your advantage to take the rim and bearings to a dealer and let them do it. They have the puller - and it's not worth buying it to do one set of bearings.

As Jack mentioned - HEAT is absolutely needed to remove the old bearings, and heat and freezing to install the new ones. You'll also need a bearing driver (which can be improvised from a humongous socket, or the right sized pipe) to seat the new bearings.

I've used - despite all the warnings not to - a propane torch to heat the hub. Boiling water was a joke, and even a 1,500W heat-gun didn't hack it. Just keep the flame soft (large - not pointed) and keep moving it around. Never let it sit in one place. DO not get it so hot that you start cooking the paint.

The bearing will usually release (you pretension it with the puller) with a small pop noise. You then use the puller to continue removing it.

On reinstallation - as Jack pointed out - it is VERY helpful to freeze the new bearing, and heat the hub. If you are very accurate the bearing will basically drop in place - but I would still want to make certain it's seated correctly with a bearing driver and the big hammer..

HTH,

[roy]

Thanks for the advice. I did take the rim to the dealer to get the bearings removed. I reinstalled them myself since heating the rim was not an issue for me. Compay I work for has a nice large low temperature oven.

Roy

[nh7robmw]

Yes - a Kukko puller to be exact..

http://tools.baumtools.com/kukko.jsp

http://tools.baumtools.com/pdf/06.pdf (you want the screw type - and use small bits of aluminum under where the legs hit the hub to prevent marring the rim..)

I wouldn't try and I've done it a number of times..
This is a case where it might be to your advantage to take the rim and bearings to a dealer and let them do it. They have the puller - and it's not worth buying it to do one set of bearings.

As Jack mentioned - HEAT is absolutely needed to remove the old bearings, and heat and freezing to install the new ones. You'll also need a bearing driver (which can be improvised from a humongous socket, or the right sized pipe) to seat the new bearings.

I've used - despite all the warnings not to - a propane torch to heat the hub. Boiling water was a joke, and even a 1,500W heat-gun didn't hack it. Just keep the flame soft (large - not pointed) and keep moving it around. Never let it sit in one place. DO not get it so hot that you start cooking the paint.

The bearing will usually release (you pretension it with the puller) with a small pop noise. You then use the puller to continue removing it.

On reinstallation - as Jack pointed out - it is VERY helpful to freeze the new bearing, and heat the hub. If you are very accurate the bearing will basically drop in place - but I would still want to make certain it's seated correctly with a bearing driver and the big hammer..

HTH,

Trying to figure out the best way to proceed replacing my '94 K75S front wheel bearings, Don, while running accross this old thread. (Btw, the bike only has 22K miles on it, isn't this unusally early for wheel bearing replacement?)

If I decide to attempt this by myself I will need to get one of those Kukko pullers you mentioned. I couldn't get the links to work but I did manage to find Baum Tools and the Kukko page otherwise. Can you tell me the size of that screw-type, please? Not sure which I'd need. They don't have any prices listed and seeing that they're made in Germany also leads me to believe they're pricey to say the least.

But my alternative is to ship my wheel off to California, having it done there and returned; still costly for me.

Seems like I might be able to do the job myself if I had the right puller, new bearings and seals and a simple propane torch as you used. I already have the freezer:laugh

[lostboy]

Matco Tools sells a nice blind-hole puller kit, which uses a slide hammer instead of pressing agains the bearing boss. I think it works better that the Kukko item.

[nh7robmw]

Thanks but I've read that the blind pullers don't work (or work so well) with these bearings. If Don recommends the Kukko that is probably the one to use, IMO.

Don, white courtesy phone, plz:dunno

[deilenberger]

Thanks but I've read that the blind pullers don't work (or work so well) with these bearings. If Don recommends the Kukko that is probably the one to use, IMO.

Don, white courtesy phone, plz:dunnoI've never used a blind puller. The Kukko has jaws the basically slip in the tiny gap between the bearing and the bearing spacer that keeps the two bearings apart, and then opens up so it can provide pulling force on the center race of the bearing.

If the blind puller is one that uses grease or some other material in a blind hole to force the bearing out - it's not going to work since the hole is open all the way though the rim - it's not blind.

It's one of these need the right tool to do the job right, or risk destroying the rim IMHO.

EDIT: Looked at the Matco website - and found http://www.matcotools.com/Catalog/toolcatalog.jsp?cattype=T&cat=2246&select=&page=2 - specifically tool #MST4581 - which should work if there is a collet that expanded enough to capture the gap on the bearing. Cost isn't cheap $250 for the set. Dunno the Kukko cost - but I can't imagine it being much more.

[deilenberger]

Trying to figure out the best way to proceed replacing my '94 K75S front wheel bearings, Don, while running accross this old thread. (Btw, the bike only has 22K miles on it, isn't this unusally early for wheel bearing replacement?)
BMW actually specifies replacement on K bikes at something like 40k or so. Thing is - that's a 15 year old bearing, with a 15 year old seal. Given the age - it isn't a big surprise that the seal may have failed (it's rubber, it gets old and hard.)
If I decide to attempt this by myself I will need to get one of those Kukko pullers you mentioned. I couldn't get the links to work but I did manage to find Baum Tools and the Kukko page otherwise. Can you tell me the size of that screw-type, please? Not sure which I'd need. They don't have any prices listed and seeing that they're made in Germany also leads me to believe they're pricey to say the least.
Dunno the size - but measure the bearing ID - that should be a big clue.
But my alternative is to ship my wheel off to California, having it done there and returned; still costly for me.

Seems like I might be able to do the job myself if I had the right puller, new bearings and seals and a simple propane torch as you used. I already have the freezer:laugh
It's not magic - but it's nice if you have someone around who has done it before. There is a bit of knack to getting the puller tensioned right without damaging the face lip of the hub the bearing fits into. And if it was me doing it - I'd do both bearings (there are different ones on the two sides also on 3 spoke rims) since the other one is equally as old.

[nh7robmw]

Thanks for answering my questions so thoroughly, Don. I think it will be best to have someone who is more experienced do this job for me before I get in over my head.

I can just imagine getting one of the new bearings stuck somehow and then I'd really be in a pickle.:hungover:banghead:violin:scratch

[SHANDELAND]

http://www.samstagsales.com/kukko.htm

[SHANDELAND]

http://www.baumtools.com/pdf/Bearing_pullers_Extracting_tools.pdf

[BuddingGeezer]

I have mig spot welded a washer to the outer bearing race. Let cool then heat the wheel, then drive the bearing out from the other side with the drift against the washer. Once that bearing is out no problem to remove the spacer and drive the other bearing. Tape the wheel hub with that aluminum tape to keep any slag from damaging the wheel.

Worked like a charm.

Ralph Sims

[nh7robmw]

Thanks, Ralph for your tip but I have no welding experience nor equipment. If I do replace the wheel bearings I'll find someone well-experienced to tackle it. Thanks to DianeH also for the excellent links provided as well.

Btw, I have a bearings discussion now going on with Don over in my "K75S DIY Painting..." thread in this same forum if anyone's interested.

[st3ryder]

I used a Gray Tools expanding blind/pilot hole slide hammer puller when I replaced my swing arm bearings on my K75. It worked very well. Are the front wheel bearings that much more difficult than the swing arms bearings to remove and replace? I was going to use the same methods as I did with the swing arm, ie heat the wheel, freeze the bearing etc.

[nh7robmw]

Same method (heat wheel, freeze bearings) but not with a blind puller:nono (see Don's posts in my other K75S DIY thread mentioned above).

Yes, it may be easy for some but I don't want to risk damaging the hub, getting a bearing stuck nor spend a small fortune on the right bearing puller for the job (that I won't be doing probably more than a few times ever).

Thanks anyway and I do appreciate the encouragement regardless!

[nh7robmw]

(see Don's posts in my other K75S DIY thread mentioned above).

Correction: See page 1, post #8 in this same thread.

[cathdeac]

You can buy tool at the bearing supply.

[st3ryder]

Correction: See page 1, post #8 in this same thread.


The tool I have is a pilot/blind hole slide hammer puller with expanding "jaw" much like the jaws of the extractor in the Kuko's on line catalogue, picture 21-01 in the link provided above. I guess my question was more about the use of a slide hammer extractor, as I *thought* I was reading that one should use a threaded extractor on the frt wheel bearings.

[nh7robmw]

OK, I suppose because it has jaws that can grab onto the backside to pull it forward that it would work fine on the front bearings as well.

I think the concern over blind pullers in general is that they force the bearings out with grease under pressure but there's no way that would work on a K75---the axle hole is open and would totally prevent pressure forming (correct me if I'm wrong, plz).