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Rear end woes.


Zot

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On my 2000 RT,42000 miles.

A couple of weeks ago I noticed a "growling" coming out of my rear end when I spun the wheel by hand. I pulled the drain plug and saw a lot of fine flour-like metal attached to the magnet.

 

Since then I have been on several short trips,always draining the rear end oil after each trip and finding the same amount of fine filings attached to the drain plug magnet and a noticeable roughness and growling whenever the rear wheel was turned.

 

I disassembled the rear end today and found the culprit,the crown gear deep groove bearing (wheel side) was chewing itself to pieces.

I noticed that the bearing cage was split in two places (opposite sides of bearing).

 

The rest of the bearings checked out fine, (although I will be replacing all bearing & seals) and not a scratch on the "crown and pinion".

 

I'm thinking that a couple of hundred miles more and I would be typing a whole different story,and I wouldn't have had any excuse,because all the "signs" were there that "Trouble was a Brewing". blush.gif

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JohnBeaven

Mine failed at about 100000km. But I think the previous owner towed a trailer so that might have shortened the life expentency.

It cost be less that $200 to replace so it was no big deal.

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I just ordered the "special" pin socket from BMW,over 100 bucks and four days wait. eek.gif

I'm going to "shop" around for the bearings, the seals I'll get from BMW.

 

I hope to be up and running in a week. cool.gif

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The newer tstyle bearing has 2 additional roller bearings inside the cage. Make sure you get the upgraded bearing. Its not uncommon for these to fail after 80-100K of service. We in Northamerica tend to drive over a lot of rough roads and overload out RT's. Believe it or not, Europe does not see as many falures. You can reinstall the seal with a Coffee Can and to remove the bearing you will need a heat run. I leave the hub assembly in the freezer for a couple of hours and the bearing slides overtop nicely! Make sure you get all the schmutz out of the hub assembly!

 

Tomas lurker.gif

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Thomas,

Thanks for the tips, I'll check the bearing when I pick it up to see if it's the updated version.

 

I'm also thinking that I'm going to start putting the bike on the side stand before "start up" after it's been sitting for any long period of time.

The oil fill/level is clearly below the level of the bearing and it would take a bit for the oil to get "slung" onto the bearing after being parked all winter, and this bearing situation has only become noticable after the first ride this spring.

Maybe a connection, maybe not.

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The newer tstyle bearing has 2 additional roller bearings inside the cage. Make sure you get the upgraded bearing.

If you are referring to the big ball bearing, the there are two variants... One from Fischer (FAG) that has 19 balls, and another from SKF that has 17 balls.

 

For years, BMW used the 17-ball SKF bearing and it worked well. At some point they switched to the 19 ball type from FAG. This one is the one that causes most of the problems. What usually happens is that the ball retainer starts to disintegrate. I guess the additional 2 balls left less room for a beefy retainer.

 

As I understand it, BMW has switched back to the SKF 17-ball type.

 

But there is no need to pay BMW prices for the bearing. It is a standard off-the-self bearing that is available from any bearing supplier that deals with SKF. I have the actual number at home somewhere.

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Heh Bob...Ive had no issues so far with the 19.....and yes they can be had by most bearing shops. The only bearing I CANNOT source is the paralever roller bearing. (BMW Only)

 

Tomas

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But there is no need to pay BMW prices for the bearing. It is a standard off-the-self bearing that is available from any bearing supplier that deals with SKF.

 

Funnily, here in the UK, the cheapest place to get the bearing are BMW main dealers. Cost around $40

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Keep in mind when sourcing bearings from a non OEM source (like a bearing house) that ball bearings come is different precision grades & more importantly different radial clearance codes..

 

I have no idea what radial clearance class BMW uses as OEM but my guess would be an unmarked (nominal) radial clearance bearing.. You really wouldn’t want to install a C-4 or C-5 class bearing in a C-2 or a nominal bearing spec application..

 

I’m not saying to not use bearing house bearings but just be aware there are different radial clearance bearing specs & I’m sure the selling price reflects the tolerance difference..

 

 

Twisty

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