Help diagnosing a noise by the final drive

[justfun1]

Last fall my '86 developed a whine coming from the rear tire area, I checked it out as best as I could and decided that the inside wheel bearing by the final drive was probably shot. So this spring I got a new set of bearings and replaced them, lubed & greased up the clutch hub and changed the oil in the final drive and made sure the backlash was OK. The oil from the pumpkin was VERY black but there was only 1 very small piece of metal on the magnet & I did not find anything in the bottom of the drain pan.

 

I got it together tonight & just got back from a test ride and am frustrated that the sound is still there . . . but much easier to pinpoint now that the bearing is corrected. I'm getting a wine that is audible from the drive shaft area of the bike. Using a long screw driver as a stethoscope and the bike running in gear on the stand, the sound is the loudest at the input of the final drive.

 

Is it likely that the drive shaft just needs to get lubed up again or something more serious?

If that is not it does the big bearing for the input shaft go bad @ about 100K?

Has anyone replaced the big bearing for the input shaft on the final drive?

Is it difficult?

OR . . . it best to start looking for a new final drive and leave that one alone?

 

Thanks,

Mike

[flb_78]

Sounds like the pinion bearing is noisy.

 

You'll probably have to pull the final drive and check for slop in the pinion shaft/cup thingamajigger.

[Freebird]

I have a spare final drive if you want to try it. I don't want to sell it so you may not want to bother with it because I would want it back. If you want to take the time to install mine and then remove it and send it back after your testing, I will sure send it to you. I'll pay shipping to you and you can pay to ship it back.

 

I'm out of town though so it will be Saturday before I could get it in the mail.

[MiCarl]

If it's a problem in the final the sound should change under load (acceleration) vs. coasting.

 

If it's constant independent of accel/decel it's more likely to be a wheel bearing.

 

The input shaft on these finals (actually the shaft on the pinion gear) is prone to breakage. When mine broke it was right at the nut that holds the coupler to the pinion shaft and preloads the pinion bearing. That is outside the oil seal so there was no debris in the oil, just noise from the extra lash created by the looseness in the assembly. That noise will change depending on acceleration or coasting.

[Zane]

Is it likely that the drive shaft just needs to get lubed up again or something more serious?

If that is not it does the big bearing for the input shaft go bad @ about 100K?

Has anyone replaced the big bearing for the input shaft on the final drive?

Is it difficult?

OR . . . it best to start looking for a new final drive and leave that one alone?

 

Thanks,

Mike

 

Here's one in our classifieds

 

http://www.venturerider.org/classifieds/showproduct.php?product=3468&title=v-max-rear-end-with-shim-kit&cat=6

[Freebird]

Yes, and I think I was premature with my offer. Mine is from a RSV. Don't know what would be required to install it on a first gen. Maybe just a blank to close of the hole for the speed sensor but I'm not sure.

[justfun1]

Thanks for the quick replies.

I drove it to work today to listen more carefully at the noise. When driving around, the noise has a pitch sounds mostly like a wind whistle and does not change pitch between the accel and decel. The pitch does change when the speed of the bike changes. Yet the sound is most definitely coming from the final drive area.

Mike

[Condor]

Have you tried putting a synthetic lube in the final?? 'Nother area you might want to consider is the middle gear bearing. Sometimes noises will tranmit away from the actual cause. Just musing...

[Venturous Randy]

Does it make any difference whether you lean a little to one side or the other as you are riding?

RandyA

[justfun1]

I had Mobil 1 in there before but yesterday I just filled it with Amsoil because friends have had good luck with it. I will have to pay attention on my way home today if there is a difference when I lean one way or the other. If there is a difference, what would that mean?

 

Sounds like I need to pull the pumpkin & shaft to figure out more.

[friesman]

Just for giggles while you have some stuff out of the way.

While you have the wheel and pumpkin out, check inside the rubber boot where the driveshaft goes into the back of the transmission and see if your bearing going on the middle drive assy is worn and has play and that the ujoint is lubricated and not worn.

 

Brian

[justfun1]

On the way home I did not hear any difference reguardless of the direction I was leaning. I did run it for a bit while on the center stand and found that there was also a lot of noise and an occasional hint of a clunk in the middle gear area.

 

I assume that to check the middle bearing you just push it back & forth feeling for movement. How would I check the cross being that you can't really get at it well?

 

So in summary it sounds like the middle gear,U-joint and the final drive might be bad.

 

Thanks again for the help,

Mike

[Venturous Randy]

On the way home I did not hear any difference reguardless of the direction I was leaning. I did run it for a bit while on the center stand and found that there was also a lot of noise and an occasional hint of a clunk in the middle gear area.

 

 

More noise while leaning may indicate more of a tire problem.

It is probably not too uncommon to hear some clunking while the bike is on the centerstand and running in gear. This is due to the angle of the u-joint with the swing arm hanging down.

RandyA

[Zane]

Does it make any difference whether you lean a little to one side or the other as you are riding?

RandyA

 

That's when mine gets noisy, on a curve at speed! Kind of a low note howl. Any ideas?

[Monty]

That's when mine gets noisy, on a curve at speed! Kind of a low note howl. Any ideas?

 

 

Are you running E3's? All of my E3's have always made noise in tight curves. I still think they're the best tire out there, though.

[Keemez]

I'm not sure if I've got the same sound as OP, but I've noticed some light ringing out of mine. Mostly on decel. It's very easy to hear it coasting down an offramp with the clutch pulled in. I've also heard of another one, roughly same vintage (early 90s) having the same or very similar sound, mostly on decel. I kind of understood that this was somewhat common to these?

[Condor]

A low growl in a curve could mean a cupped tire....

[Zane]

Are you running E3's? All of my E3's have always made noise in tight curves. I still think they're the best tire out there, though.

 

No I've got a new Shinko on the back and before that a 404 (?) that was worn to the core when I got scared enough to pop for a new tire. It made the noise before the new tire. I think I will be pulling the pumpkin and drive shaft to see if it may be the problem in play!

Thanks

[Canadian Venture]

Same problem with mine and took panel off and put a screwdriver in the universal and sure enough it was loos and had play in it.

 

G Luck!