rear wheel noise / grinding

[Matt Chapter]

As I mentioned in another thread, I've been hearing some clunking from the rear somewhere when backing out of the garage.  On the centerstand, when I rotate the rear wheel, I can feel something rubbing / grinding, and it sounds a bit like a "whiiir" plus the intermittent clunk.  My swingarm bearings seem to be fine.. I'm not sure where to look next although I suspect I need to dismantle the drive shaft.

I also topped off the gear oil, no affect.

What noise / feel would be normal when you rotate the wheel by hand?

Anybody have a magic wand they want to wave? (Keeping in mind that this is a monoshock frame.)

[Bob_Roller]

I would drain the oil in the final drive and drive shaft and see if there is any excess amount of metal in the, before I did anything .

I hear no noises when I rotate the rear wheels on my R65's .

[montmil]

Matt,   Have you removed the rear wheel for a visual? There should not be any strange noises when you manually rotate the rear wheel while on the centerstand.

Could a brake shoe be off it's pivot and rubbing on something?

Check the splines. Look for any metal trash that might be inside the rear brake area. Remember those open to ambient atmosphere vents in the rear hub? Could be some bit of Austin Limestone got lucky and caught a ride with you.

[Luca]

A little bit of transmission noise is normal when rotating the back wheel, but it should feel smooth and sound even.  Maybe some light ticking and whirring, but nothing "heavy"

If everything looks good inside the rear end, inspect the driveshaft at the front end, underneath the big rubber boot.  It sounds like the U-joint or flange bolts are cooked.

[Matt Chapter]

I did take the rear wheel off.. plenty of brake pad left, nothing out of the ordinary.  I suppose the next thing is to drain the oil as Bob suggests, and maybe peak into the boot of doom.

At least it's been wet here, so I'm not missing out on anything.

[montmil]

Draining and checking gear oils is a good idea. You might be able to poke a magnetic pick'em up stick into the case and hopefully not pick up anything.

I'd for sure peek under the driveshaft boot.

You mentioned hearing the noise when you roll the bike backwards outta the garage. There's a certain amount of lash within the drive line components and the 'going backwards' might suggest a backed out U-joint flange screw making the occasional contact/clunk/grind noise. Look for any scuffed spot on the screw/s.

Way too early to panic. It's going to be something simple. Cautiously optimistic here.

[tvrla]

There are three possible things to check out:

1. UJoint
2. UJoint flange - bolts loose?
3. Transmission bearings

If it's not #1 or 2, then that leaves #3. A clunk rotating the wheel in reverse is a standard way for checking ujoints and bearings on the paralever GS.

If there's more than soft fuzz on the trans drain plug magnet - like slivers or chunks - time to stop riding. Right now! It's exponentially more expensive to repair with each additional mile!

[Matt Chapter]

Just realized on the way home that if i'm going to drain the transmission oil, i'd better go ahead and replace the neutral switch.  Motobins to the rescue! Too bad I remembered on a Friday evening.

I recently chucked my oil drain pan because it was a leaky piece of junk.. what do you guys like to use, especially if it fits nicely between the center stand and the wheels?

[Barry]

I recently chucked my oil drain pan because it was a leaky piece of junk..what do you guys like to use, especially if it fits nicely between the center stand and the wheels?  

An old Turkey roasting tin.... I did buy her a new one.

[Luca]

Nothin but the best for my baby... all her fluids are drained into a silver bowl!

[Matt Chapter]

Finally drained the transmission oil.  Here's a shot of the drain plug with metal spurs..  Feel free to speculate wildly.



Good, bad, put a beer on it??

[Bob_Roller]

My best guess, would be bearings .

I had water getting into the transmission in the late '80's to '93, until I found that the speedometer cable drive boot was the culprit .

Water / rust damage on the bearing races .

You could try changing the trans oil and run it for a while and see if you get the same amount of metal on the drain plug .

Have you changed the trans oil before ?

[flybot]

If its been awhile (10k+ miles?) or its been an unknown amount of time, Id say the drain plug looks normal. Little splinters happen. Chunks or bits, or a whole lot more of the splinter type metal would be a different story. If it was me, I would look closely at the sediment of the oil you drained out. I would not give that an automatic doom diagnosis.

[montmil]

Matt, Removing the Cardan cover on the final drive is very easy. Not even necessary to remove the rear wheel. You will need a fresh paper gasket when going back together. Hopefully, Lone Star will have one tucked back with the seldom called for Airhead parts...

With the cover off, it's another easy bit to lift out the spline cup and expose the bevel gear innards. Watch for and capture the large diameter shims and replace them as removed.

Kerosene would do well to flush out the final drive. You can rotate the rear wheel and inspect gear teeth although the bearings can only be checked via a full disassembly. There is also a large ball bearing that can be cleaned out and checked for scratchy racket. It comes away with the spline cup assembly.

As suggested, clean out as best you can, oil the big ball bearing, put 'er back together and don't forget to add the gear oil! Go for a ride and see how she sounds. If you wish, drain the gear lube again and check for fuzz.

Luck, amigo.

[Matt Chapter]

That's about 1500 miles worth of riding.  Previous change at 5000 mile interval had similar fuzz on the drain plug. I was thinking about checking the universal joint yesterday but then the wife opened the garage and let the warm air out.  That and my Haynes compendium had no reference to it.

Monte if the final drive drain bolts are clean, is it worth peeking inside the cover?