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Posted (edited)

I have a problem I'm trying to diagnose before tearing into my Millenium.

Some history:

Have owned it since 2002 when it had 10,000 miles on it. Now has 60,000 miles on it. Do all my own maintenance.

Carbs synched. Valves set. Runs great.

 

I have a pronounced low speed rumble/thumping/vibration upon clutch engagement and then just before rolling to a stop. Actually, just before a dead stop when I put a foot down.

It's been doing this for awhile.

For rear tire replacement and general servicing, I've had the rear end off and driveshaft out a few times.

I recently replaced the driveshaft seal at the rear end due to weeping.

Thorough inspections did not reveal any mechanical failures back there.

When I'm above idle, I don't experience this vibration.

I've tried pulling in the clutch and/or going into neutral before the rpms drop to idle. No changes in symptoms trying either.

I was in stop and go traffic on the interstate yesterday and had a lot of time to experience it with the low speed "on the clutch, off the clutch" rolling along at near idle.

I'm trying to discern if it's engine or driveline.

I'm thinking maybe the u-joint.

Seems I read on here somewhere (or maybe on the VMax forum) where the pinion shaft (just behind where the nut threads on) or something at the end of the driveshaft at the differential would break.

(SEE THIS PHOTO OF A SIMILAR TYPE FAILURE OF WHAT I'M TALKING ABOUT).

But I can't locate that with searches.

Any ideas if this info was posted here before?

Any other ideas about troubleshooting or diagnosis tips?

Thanks.

Broken pinion.jpg

Edited by Beau-Kat
added photo
Posted

I do have another RSV diff with only

about 5000 miles on it.

I installed a shock bolt and blanked the speedo hole and ran in my VMax for awhile.

Posted

Think if it were mine Kat I would reach in and smack the side of the rear caliper with a rubber mallet hard enough to be able to feel looseness - so the rear pads are backed away from the rotor a little. Then ride it without hitting the rear brakes and with no chance of brake drag and see if it makes a difference.. I have heard of some 2nd Gens wearing rear pads at an angle with the diagnoses of the rear pig needing to be shimmed to bring it into proper alignment - is there any chance your scoot is one that has this wear sign?

Also, you mentioned a weeping seal? IMHO, seals dont always go south just because they get old, sometimes a failing seal is the result of a bearing issue. Because your dealing with u-joints in shaft alignment it is entirely possible that you have a failing U-Joint but, my experience has been vibrations at higher speeds than your talking being the result of a failing u-joint. Noisy U-joints at lower speeds (squeekin) would be more common - IMHO..

Here's a thought,,, wonder if slipping the drive shaft out of the front splines, rotating it 90 degrees, greasing it back up and putting it back in may help..

I have also had some strange vibrations happened at speeds like you are talking about that disappeared with clutch pressure.. Ended up being a bad bearing on the clutch basket shaft.. Do you feel it if the bike is leaning on the side stand and feel it less when you stand the bike up or is this only when the bike is in motion?

Posted

If you have had the pumpkin off then there is a proper procedure on reinstall. Did you follow that procedure?

Install pumpkin, do not tighten bolts. Install wheel and rotate the shaft to where it feels the easiest to rotate. Snug up shaft. Now tighten pumpkin to driveshaft tunnel and lastly torque the axle shaft.

Posted

Since it's pretty constant with starting and stoping have you thought about the front wheel bearings?? Could be a rumble from a worn race that disappears when rotations speed up?? Just a WAS.....

Posted

Beau,

 

From my experience with a similar break..except mine was in the rear end of the drive shaft... the only way I knew there was a failure was the whine increased during decel. No vibration at all. I would think maybe ujoint dry or ??.... and you may be able to get a peak at the ujoint by pulling boot back and peering down between left side cover and frame. If you put her on a stand, you can spin the rear wheel and see if ujoint is loose. Have you tried starting scoot on stand and putting it in 1st gear at idle and let it turn rear wheel while you search for rumble/vibration?

Posted (edited)
Think if it were mine Kat I would reach in and smack the side of the rear caliper with a rubber mallet hard enough to be able to feel looseness - so the rear pads are backed away from the rotor a little. Then ride it without hitting the rear brakes and with no chance of brake drag and see if it makes a difference.. I have heard of some 2nd Gens wearing rear pads at an angle with the diagnoses of the rear pig needing to be shimmed to bring it into proper alignment - is there any chance your scoot is one that has this wear sign?

Also, you mentioned a weeping seal? IMHO, seals dont always go south just because they get old, sometimes a failing seal is the result of a bearing issue. Because your dealing with u-joints in shaft alignment it is entirely possible that you have a failing U-Joint but, my experience has been vibrations at higher speeds than your talking being the result of a failing u-joint. Noisy U-joints at lower speeds (squeekin) would be more common - IMHO..

Here's a thought,,, wonder if slipping the drive shaft out of the front splines, rotating it 90 degrees, greasing it back up and putting it back in may help..

I have also had some strange vibrations happened at speeds like you are talking about that disappeared with clutch pressure.. Ended up being a bad bearing on the clutch basket shaft.. Do you feel it if the bike is leaning on the side stand and feel it less when you stand the bike up or is this only when the bike is in motion?

 

Thanks Puc.

Mine has worn the rear pads unevenly in the past. I haven't whacked the caliper yet, but will try that. But it doesn't feel like a dragging pad or warped caliper. It's like something spinning just wobbles before I stop. Like I said, I've tried without hitting the brakes, clutch in or out, in gear, or in neutral, same feeling. So I don't think it is related to engine rpm, but definitely to something spinning and slowing down from speed.

I have the Royale, the RSV, and the VMax and have been all over these bikes during maintenance. So, I've had the diffs pulled several times for maint or swapping on the RSV and the VMax.

You're also correct in assuming the driveshaft seal didn't just fail on its own. I damaged the driveshaft seal while re-installing the driveshaft after servicing it.

The clutch basket shaft bearing mention is interesting. I'll put that on my list. Could very well be that.

I'm going to be checking one thing at a time to try to eliminate singular concerns.

I'm also going to install my other RSV diff that I had mentioned running in my VMax for awhile. It has far fewer miles on it.

May do the 90 degree rotation on the driveshaft remedy also, if warranted.

Thanks again.

Edited by Beau-Kat
additional info.
Posted
If you have had the pumpkin off then there is a proper procedure on reinstall. Did you follow that procedure?

Install pumpkin, do not tighten bolts. Install wheel and rotate the shaft to where it feels the easiest to rotate. Snug up shaft. Now tighten pumpkin to driveshaft tunnel and lastly torque the axle shaft.

 

Thanks Marcarl.

I know and have used that procedure always.

Posted
How are the pins and splines in the rear wheel. I had a similar vibration that turned out to be dry rusty pins.

 

Thanks Flyinfool.

I have removed, inspected , and serviced those pins a couple of times over the years. The strange vibe was there before I did that the last time (a few months ago).

Posted
Beau,

 

From my experience with a similar break..except mine was in the rear end of the drive shaft... the only way I knew there was a failure was the whine increased during decel. No vibration at all. I would think maybe ujoint dry or ??.... and you may be able to get a peak at the ujoint by pulling boot back and peering down between left side cover and frame. If you put her on a stand, you can spin the rear wheel and see if ujoint is loose. Have you tried starting scoot on stand and putting it in 1st gear at idle and let it turn rear wheel while you search for rumble/vibration?

Thanks Videoarizona.

I have a full shop lift table and my bike also has a Rivco centerstand. So, I have had opportunity to try to replicate the vibe with the rear wheel off the ground. Going up and down through the gears, increasing speed, then dropping speed to stopped in each gear. Can't seem to replicate the vibe that way. Almost seems as if the frame/suspension has to be loaded to feel it.

I had felt a low speed hump, almost like a tire out of round or a bias ply trying to warm up and come into round. I removed my rear axle and inspected it. It did have the slightest bend in it. But I went ahead and bought and installed a brand new rear axle a couple months back. Don't feel that hump anymore.

I also bought a new rear axle bearing, but did not install it yet. Mine looked and felt good. May be going to install that next.

Posted (edited)

Another point:

 

I had to repair my clutch slave cylinder due to leaking last summer. So, I had the middle gear cover off for that procedure. I did a visual and "hands on to see if anything wobbled" inspection of that bearing. All seemed good and tight.

 

And, I'm going to be pulling my front wheel and checking my bearing up there too.

 

Thanks guys for all of your suggestions. I'll let you know what I eventually find to be my problem.

Edited by Beau-Kat
Posted

Your more than welcome Kat..

 

Thinking more about this and wondering if you may be actually feeling a tire issue.. Maybe put the scoot up in the air and spin the tires and watch em closely as you do.. If this started at a tire change - may check the "bead line" on your recent tire install and make sure the bead is set in properly. Also double check your front tire for wear too.. Jack mentioned to check you front wheel bearings, good suggestion IMHO. Also, just for kicks - if its a "wobble" you might wanna check your swing arm bushings for wear and also maybe your triple tree bearings for looseness..

FYI,, I bought a brand new tire once that had a similar "feel" to it after install.. Sort of wallowing feel just before I stopped - sorta spooky really.. Come to find out it was all about a flaw in the casing of the new tire... It happens...

Posted
if you happen to be running a metzler marathon on the bike just check it is not lifting the tread. i found this out recently on mine.

Thanks.

I am running Metzelers.

My third set on the RSV.

I've also run them on my other bikes for many years.

I install them myself and have had good performance and mileage from them.

Current ones have 5000 miles on the rear, a couple thousand on the front.

I see no problem with these tires.

Posted

I'm working on a Katana and a Suzuki Savage right now.

Soon as I get those outa my garage, I'm gonna put the Millenium on the lift and find out what's troubling her.

When I'm done with that, I'm gonna start installing my sidecar on the Royale.

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