Grinding Noise

[Deltamark]

Just got back late this evening from a trip to Cincinnati, OH on my 99' R1100RT with my wife. Did about 500 miles in 2 days. On the way back today, I started to notice what seemed to be a wheel noise that got progressively louder. By the last 30 miles, I was real concerned because the noise sounded like metal grinding. My wife said that it sounded like it was coming from the rear and since I recently changed the rear pads, I pulled off to check them, but they seemed OK. I'm not 100 percent certain it was coming from the rear. I checked the front wheel, but didn't notice anything.

 

I'm almost afraid to ask, but any suggestions on what I should look for? I'm not an expert wrencher and am hoping this is something I'll be able to tackle. I'm figuring I'll pull off both of the wheels and see if anything is noticeable.

 

As always, I appreciate any advice from this forum!

 

Mark

[Stan Walker]

The first thing I would check is the final drive.

 

Put the bike on the center stand with the rear wheel off the ground. Put bike in neutral. Grab rear wheel top and bottom and try to rock the wheel and see if there is any play (should be none). Try the same thing with your hands at the 9 and 3 oclock positions (should be none hee too).

 

Spin the wheel. It should spin without any crunchy or grumbly noise or feel.

 

Look for oil leaking from the final drive. That would be a bad sign if it's coming out past the crown wheel seal (on the left side of the final drive).

 

Stan

[Boffin]

If having checked everything Stan has covered you find nothing wrong, take a look at yout tyre. Is it cupped? I had a complete rear and and gearbox stripped under warranty by my dealer looking for what sounded and felt like a dead bearing. It turned out to be a worn Avon Azaro

 

Andy

[Eckhard Grohe]

 

Ouch... Do you still frequent that dealer for other than parts???? I hope not.

[DrPaul]

Mark,

If Stan's recommended FD bearing test is normal, do these things:

1- Pickup a quart of 90W or 75W-90 GL5 hypoid gear oil for the final drive (FD).

2- With the bike on the center stand, remove the FD filler plug and make sure the fluid level is somewhere near the hole. If the fluid level is not visible or you can't touch it with your pinky finger, measure the volume of fluid you drain out in step 3. The FD holds about 250cc.

3- Drain the FD into a clean container and look for any bits and pieces of metal. The magnet in the drain plug will have a small amount of black metalic "dust" on it and this is OK.

4- Replace the drain plug and refill the FD unless you found metal bits in the old fluid in which case the unit will need work. If the fluid volume was very low, it could have caused your symptoms and I would suspect a leak.

 

Good luck and hope it turns out to be an easy and cheap fix!

 

Paul

[Deltamark]

Thanks Stan, Andy and Paul,

 

- I put the bike on the center stand and checked the rear wheel to see if there was any play, but could not detect any.

- When I spin the wheel, I do hear a slight grumbly or gindy noise, though.

- I see traces of smudge around what I believe is the crown wheel seal. Not sure if it's a leak there.

- My tire is cupped, but I've seen that before. I do a lot of NW Ohio straight / forward riding on the turnpike during my commute. I assumed that is what caused by tire to wear like that.

- Checked the final drive and the gear oil was not visible from the plug. (DOOHHH!) I drained it and it wasn't too bad. Just a bit below the 250 ml mark. I did notice some silvery metal shavings on the ground near where I drained it. Probably from where I was cleaning the magnetic drain plug. The fluid I drained look like mud. There seemed to be very small silvery specks in it. I wish this was a brake issue, but it's looking worse, isn't it?

 

On another note, I changed my final drive about 1,800 miles ago. Because of goofup I made in mixing my new and used BMW gear oil in the drain bottles, I ended up going to an Auto Zone and using Valvoline Synthetic Duroblend 80/90 GL-5 for the final drive. Not that it matters to my ego, but I'm hoping that isn't the cause of this.

 

Anyway, not sure what I'm gonna do next. I've sunk a fair amount of dough into this bike already in the 18 months since I bought it (my first bike), and I do love it, but I guess I underestimated what it would take to own one of these machines.

[OoPEZoO]

Definitly sounds like you lost the crown bearing in the final drive. Mine failed last weekend (for the 2nd time), and I'm having it rebuilt at the dealership right now. When mine failed on me last summer I tore it apart and rebuilt it myself but it only lasted 10k miles before it failed again last week due to it not being shimmed properly. This time I figured I would let them mess with it so it I know it is done correctly. Here is the link to my posts about it.

 

Final Drive Failure

[DrPaul]

Mark,

The FD fluid should never look like mud! In fact, unless it has a lot of miles, it should look pretty much like it did going in since there are no combustion products getting in there like your motor oil. I don't know why the oil you put in 1800 miles ago would have caused this. Others may have a different opinion. I run Castrol Syntec 75W-90 in mine and never had a problem. Definitely sounds like a significant FD bearing failure. I guess there are no insignificant bearing failures, huh?

 

Paul

[Ken H.]

Anyway, not sure what I'm gonna do next.

Drain the FD as mentioned and check for metal. If it has bearing going there will be evidence of it in the lube.

[Deltamark]

If this does turn out to be the final drive, anyone have any thoughts on replacing with a used unit vs. having it rebuilt? If I bought a used one, is it fairly straight-forward to replace?

[T__]

If this does turn out to be the final drive, anyone have any thoughts on replacing with a used unit vs. having it rebuilt? If I bought a used one, is it fairly straight-forward to replace?

 

Mark, probably easier & quicker to install a new crown bearing & oil seal in yours.. Get another used unit & you are just asking for the same type problem..

 

It isn’t a difficult job to install a new crown bearing (usually what the problem is)..

 

Make sure your problem isn’t brake related like caliper touching the rotor or the brake ABS sensor grounding out..

 

If the grinding noise in not once per revolution of the wheel then suspect something else like loose exhaust or exhaust touching the center stand..

 

Maybe get the noise to appear then shut the engine of & coast down through the grinding range.. That should yea or nay the rear end..

 

Twisty

[Ken H.]

If this does turn out to be the final drive, anyone have any thoughts on replacing with a used unit vs. having it rebuilt? If I bought a used one, is it fairly straight-forward to replace?

 

Mark, probably easier & quicker to install a new crown bearing & oil seal in yours.. Get another used unit & you are just asking for the same type problem.

I have to disagree. The shimming of the pre-load of FD is so critical that unless you have access to a good shop, it's tough for the average DIY'er to get it right to avoid a repeat failure. And there are a lot of good used FDs out there relatively inexpensive. Replacement is straight forward, unbolt the old, bolt up the new. If it was me (and it turns out your's is indeed toast) I'd put in a used unit and ride it out.

[smiller]

Mark, probably easier & quicker to install a new crown bearing & oil seal in yours.. Get another used unit & you are just asking for the same type problem.

I have to disagree. The shimming of the pre-load of FD is so critical that unless you have access to a good shop, it's tough for the average DIY'er to get it right to avoid a repeat failure. And there are a lot of good used FDs out there relatively inexpensive. Replacement is straight forward, unbolt the old, bolt up the new. If it was me (and it turns out your's is indeed toast) I'd put in a used unit and ride it out.

I kind of agree with Ken here. A lot depends on the individual circumstances, but unless the home mechanic has the tools and skill to set everything up properly I'd go with a low-miles take-out unit if I could find one (I see them around quite often for around $300 or so, although of course not when you actually need one ). Either method will entail some risk and there's always the potential that there could be something wrong with a used part, but if you shop carefully I'd say that on the balance it's the best way to go. From what I've read so far the home repair jobs seem to be hit-or-miss... I've read of a number of both successes (at least for the short term) and failures with the 'replace the crown bearing and pray' method.

[Deltamark]

Thanks all,

 

I'll check the brake and caliper and hope like heck I do find something there. If that doesn't do it, I'm thinking I may have to take it to the shop for an accurate diagnosis. There's a former BMW mechanic who works at a place about 75 miles from my home. He knows my bike would probably help me get a used FD, should I want to go that way.

 

Mark

[Deltamark]

I decided that I want to pull off the final drive and take it to a dealer to have them rebuild it. Given that, can anyone tell me if the removal is pretty straight forward? Any special tools required?

[OoPEZoO]

It is pretty straight forward, but you will need two somewhat out of the ordinary tools.

 

1. 12mm allen wrench/socket. Most allen socket sets only go to 10mm. I bought a normal 12mm allen wrench from Sears and then chopped about an inch off of the end so I could use it in a socket. It worked like a charm.

 

2. You will also need a 30mm socket. Its normal to have one in my garage, but some people don't keep things around that big. You can get a cheap, but good quality impact socket set from Harbor Freight if you need one.

 

Other than that, all you really need is some Loctite 270 and a torque wrench. Here is a nice link to help you out. If you have any specific questions, shoot me a PM. I just reinstalled my final drive last Saturday so it is still pretty fresh in my mind.

 

Just as a heads up.....mine cost me $425 to have it rebuilt (both bearings and reshimmed). It worked out to $180 in parts + 3.6 hours labor ($60/ hour) + 6% sales tax

 

Final Drive R&R

[Mark K]

I decided that I want to pull off the final drive and take it to a dealer to have them rebuild it.

 

 

I think that is the way to go. In fact, why remove the drive? I let my local (ex)dealer have my bike for a couple days. It came back better-than-used with a new crown bearing and seal for $266.92.

[Ken H.]

I decided that I want to pull off the final drive and take it to a dealer to have them rebuild it. Given that, can anyone tell me if the removal is pretty straight forward? Any special tools required?

You usually have to heat the pivot pins quite a bit to soften the existing loctite.

[OoPEZoO]

I decided that I want to pull off the final drive and take it to a dealer to have them rebuild it. Given that, can anyone tell me if the removal is pretty straight forward? Any special tools required?

You usually have to heat the pivot pins quite a bit to soften the existing loctite.

 

Good point.....something else I forgot to mention and take for granted....a heat gun.