Grease wheel bearings or not?

[Dr. Strangelove]

I will be changing tires in the next couple of days for an upcoming ride to Torrey. On the BMWST forum a poster there said that while he is in there changing tires (presumably on an RT) he squirts some "Red Waterproof" bearing grease into the races.
He reports that gunky old grease emerges when he does this and he thinks this is a good idea.

Ok,

I read that the bearings on the RR are sealed, but I suspect that there is a crease through which a small catheter attached to a syringe could force grease in there.
Is this a good idea or not? Bike has 64k+ miles and to my knowledge this has never been done (maybe because it doesn't need to be).

And if it is a reasonable thing to do, what grease to use?

Again, the wisdom of the internet tells me that lithium based greases are NOT water proof. For that calcium or aluminum is required, instead of lithium. Also, the internet tells me NOT to mix types of grease. At Pep Boys I picked up some Mobil One high performance wheel bearing grease. It is red. It is highly "water resistant." It is excellent for "high temperature" operation. It meets/exceeds NLGI-1 standards.
Most other greases there were blue, including a Castrol product. None claimed to be "waterproof," but this may be the trial lawyers at work.

Advice appreciated and TIA

John

[iowabeakster]

Nobody answering... and you sparked my curiosity... so, I looked at the service manual.

Here's what I see...

1. There is a wide bearing and narrow bearing (the wide one is on side with the speedometer drive unit)

2. On the side with the wide bearing there is: a seal, the speedometer driver ring, and a snap ring that need to be removed to get to the bearing.

3. There is no mention of a seal on the narrow bearing side... there is a bushing on that side. I am not sure if the narrow bearing is a sealed unit itself... or if there is a separate seal...or if the bushing acts as the seal. The instructions simply say to use a bearing puller to remove it. Anyway, I can't tell if that bearing could effectively be greased or not from the instructions and pictures (I also do not have an adequate mental image).

Once the narrow bearing is pulled... the wide one can pounded out through the hub on the other side.

So, unless you are thinking of pulling the bearings out, I think that some fresh grease could be applied (to one side...the outboard side) to the wide bearing. But, I doubt that would very effectively remove the old grease (or dirt, if present). And, I'm not sure if the same could be done for the narrow bearing. You might try and remove the bushing to see.

If the bearings were removed... nah...

IMO, I wouldn't bother to remove them unless they were no longer turning smoothly... they can't be that expensive.

edit---I looked them up... 16 bucks for the narrow bearing... 54 bucks for the wide one. I guess I underestimated BMW parts pricing policies.

[riceburner]

I've "just" (about 4 months ago) replaced my front bearings.

Unfortuantely - I can't remember if the ones I fitted were sealed or not - I THINK they were, but I also think they weren't the OE BMW ones - I got them from Motorworks rather than BMW.

FWIW I did put some grease (lithium) around them (on the spindle mainly) and now I think a lot of it is being flung onto the wheel rim - certainly the wheel rim get VERY filthy, VERY quickly these days - it can't ALL be brake dust....

[Dr. Strangelove]

Thanks for the replies. Yes, I saw the manual also. No mention of lubricating the bearings did I find.

I've changed my tires once previously and I couldn't remember what the layout of the bearings was, but I most certainly do not want to get into pulling bearings out, and then having to press them back in.

I will inspect them, but the wheel turns as smoothly as it always has, and I do not feel any rough spots as I turn the wheel slowly, so I may just treat the bearings with some carefully observed neglect.

How many miles were on them when you replaced them, Riceburner, and what prompted you to do that?

John

[riceburner]

How many miles were on them when you replaced them, Riceburner, and what prompted you to do that?

John

errr - 73 or 74,000 miles and they were f u c k e d. (that's a valid technical term btw)

(there was about a 5 degree wobble on the wheel from left to right, and you could hear and feel them grinding as you rotated the wheel by hand)

If you've got a smooth roll on the wheel, and no sideways movement whatsoever, they're fine.

[Dr. Strangelove]

ah ha, thanks

so it ain't no shade of gray it would appear.

I'm going in.

[boxermania]

Doc Love

Bearings can be obtained in three states of protection.....open, shielded and sealed. Our bikes use the sealed type, which have a flouro elastomer sealing it to outside influences. They do not require any additional greasing nor can they be greased.

The life of the bearing in our applcation is fairly long, only affected, by load, heat, rollling surface roughness and undue impactation. Yes they will fail, but it will be in a predictable fashion.

Once they start in teir failure mode, the first thing that will happen, would be slight rougghness when turning the tire in the direction of rotation and will increase predictably over a fairly lengthy span of time.

That being said, if the tire turns freely and there is no side to side play, your bearings are OK.

Enjoy your trip.........

[Dr. Strangelove]

Hey, Al

thanks to all for the sage advice.

I removed the front today and two things stood out:
1- they looked very clean in there
2- they looked hard to get out

Decision made; leave them alone. I did clean out the geared speedo assembly and put some grease in there. It looked pretty gunky.

John

[CycleRob]

Here's what's inside. Examining the parts closely, I saw premium quality bearings, especially the quite heavy wide one!



Greasing them is not a good idea because of the destructive contaminates that may be unknowingly introduced. Also, chances are the selected product won't be the ideal grease.

Best things to do:
-- Do not ride in the rain.
-- Do not power wash near the bearings.
-- Protect bearings from engine cleaners.
-- Avoid dirt roads.
-- Avoid hitting potholes.
-- Enjoy the ride until wheel side play or growling noises appear.

.

[ebincia]

Cyclerob,


Thank you for your ( once again) excellent contribution.

[riceburner]

Best things to do:
-- Do not ride in the rain.

.

Umm - not a lot of choice in that area, and frankly, if the bike can't take it - it shouldn't be on the market.

[boxermania]

As mentioned before, these are sealed bearings and the best choice to keep foreign matter, solid or lquid, off the races. They take well to operation in the rain, total inmersion for extended periods of time is another story.........

[CycleRob]

The problem with rain isn't just the water. Take a look at your muffler after a rain ride . . . . really dirty, isn't it. That's the stuff, the fine silty grit, that over time slowly hones the rubber seals bigger. Not to worry, it'll likely take years and well past the warranty period to cause the seals to leak. Or sooner than that if rain rides are a higher percentage of your rides.

In another application that few people worry about, the U-joint bearings on the differential pinion shaft of rear wheel drive cars/trucks survive many times more hostile conditions and hundreds of rain storms for decades without any damage. In that application the bearing seals are actually churning at very high speed in the dirty water stream. They do have very heavy duty high quality rubber seals and a premium grease pack, so they represent an amazing design success. The seals on wheel bearings are hard rubber and are just snapped into place. They're almost easy to remove (if you don't mind damaging them).

.

[boxermania]

Robbie

Your explanation is most welcome, however, seals on U-joints (Cardan joints) are quite different in application from typical rolling element bearing seals.

U-joint seals are held in axial compression between the bearing cup and the receiver (U-joint body) these seals don't experience any rotation as what is rotating are the needle bearings inside the cup. In the case of rolling element bearings the seals are in a radial application and there is a bit of drag on the bearing as the seal is rotating with one of the races and sealing against the other.

Shielded bearings, on the other hand are different, as the shields are typically metal and there is a slight clearance between the shiled and the bearing race, which in this case doesn't induce rotational drag.