Talking about Vibration...

[Valk-Obsessed]

There was a recent thread concerning vibration that was seemingly coming from the rear wheel area.
I'm still pretty much a Valkyrie Newb...so forgive my silly questions.  Here is some background to start with...  I recently had my rear wheel off on my I/S.  I replaced the Dampers, inspected the splines, and lubed drive shaft and pinion cup, etc. Per instructions of "Rear end service" from Shop talk... Compared to photos I've seen of what is supposed to be good, I would say my splines are fine.  Also replaced O-rings and Thrust washer.  I feel some vibration "under load", that seems to go away when I pull the clutch lever. 
 Is some vibration normal? If so, how much?  It doesn't seem like it's bad, but if it's not supposed to be there, I need to figure out the source. 

[Valk-Obsessed]

Did some searching...
The one thing I haven't looked at yet is the U-joint...So I guess that is a possibility...Are there other ways of checking it without a Vice?

Thanks to this group, and you-tube, I've worked on parts of the bike that really seemed intimidating...So thank you all for the wealth of knowledge to be found here.

99 Interstate with just a little over 6o thousand miles on the clock.  I'm the second owner, and have had it about a year and a half. 

I think there has always been some vibration through the pegs...but since I've "worked" on some things, I'm really freaked out about screwing something up!

[Bone]

You answered my question the U-joint came to mind. I'm not aware of other methods to test without a vice.
I had one go out the vibration increased quickly. I tore it down rather than get stranded.

[Jess from VA]

When my U joint went bad, I had a distinct thumping in the foot pegs (and grinding in short order).  But mine completely failed and was toast.... and there was no mistaking that something was wrong (by the time I got about 45 min slow ride to home).  I have no experience with a U joint that may only be.... slightly impaired.  It was about the same thing when I lost my left (single row) rear wheel bearing... thumping, grinding, squawking (and I had to ride slowly about 40 minutes on it too, to get to a place to work on it).  Both came out destroyed, beat up, falling apart.... so no need for a close inspection.

One way to check (not scientifically) the U joint short of a tear down is to go out in front of the house very slow in 1st and just easily goose the throttle (quick throttle blips), to get a feel for drive line slop. Since you changed the dampers, you know that's not an issue.  If too aggressive, this could also exacerbate a failing U joint.

You can also put it up on the lift, wheels just off the ground, start and put the bike in gear, and do the same thing.  You can also pull the right side cover, move the rear brake reservoir cover, reservoir and bracket out of the way, and pull the boot back and try to inspect it for visual damage without removing it entirely, but this will only show obvious damage, not minimal damage that could only be shown by removing it and testing it on the bench.  Putting the boot back on can be a real SOB (get the swing arm as high as it will go).  

See this link for U joint R & R.  Click each photo for more detail.  http://www.rattlebars.com/mtz/ujoint.html

Wheel bearing can be sort of checked on the lift by trying to move the wheel side to side laterally, but this is also imprecise.

The fact you have been riding the bike trouble free, except for some small intermittent vibration, might indicate that neither the U joint or wheel bearing is a problem.  Once they start to go, they usually self destruct in short order and there is no question there is a mechanical problem.  

A small vibration (without mechanical failure) would always make me think of my tires first.  You can also put the bike on the lift, put it in gear and let the rear spin and eyeball it for balance and uniformity. Always be careful running in gear on the lift, and use the rear brake to stop the tire spinning.    

  

[Tfrank59]

If the vibration under load goes away when you pull in the clutch then it probably isn't your tires although that would have been my first guest too. It may well be something in your drivetrain or it possibly could even be your clutch. It's probably not in the final drive because you've gone through that sufficiently, so that leaves the U-joint or the wheel bearing or course as I mentioned the clutch since you say the vibration ceases when you pull it in. Let us know what you learn.

[longrider]

I had those exact symptoms on my first valk at about 75k.   The ujoint was beginning to seize as it was dry.  A new joint to install and a spare one for next time
came a few days later via the brown truck and the phat  girl was smooth again

[Valk-Obsessed]

Thanks for the tips and ideas.
I'll have another look over the weekend...I hope it's not a u-joint issue...that seems like a pain to get to.

[The emperor has no clothes]

Thanks for the tips and ideas.
I'll have another look over the weekend...I hope it's not a u-joint issue...that seems like a pain to get to.

Its actually not too bad. The hardest part is getting the cursed boot back on right.

[Oss]

IMHO get a new boot if you are getting a u joint

My ujoint grenaded around 90k  and wish I had thought of getting that boot then

here is one story
http://www.valkyrieforum.com/bbs/index.php?topic=84105.0

[longrider]

If you need more info on the install let us know.  The swingarm does not need to be removed

[Firefighter]

I found my u joint bad during the regular rear end maintenance. Most of us hopefully take the rear wheel off at 10,000 miles or so and do this maintenance. The u joint removal and grease splines is part of the maintenance. Four nuts and pull the pumpkin and drive shaft, then remove the chrome brake cover and let the rear master cylinder hang. Pull the boot back and wiggle the the u joint back and out.

Mine was loose and I could feel it without a vise, never knew it from riding. I don't usually use a vise just my hands. I don't ride hard and downshift hard so hope I will not have trouble.The biggest deal is use the manual and follow directions, torque sequence exactly! Let us know if you have trouble as there are a few tricks to doing things easier.

[Valk-Obsessed]

I tried the driving around in first, and goosed the throttle a little...it's a bit jarring when I do that...I'm going to replace the u-joint.  I haven't taken in out yet...(Gathering parts first) but will probably do that next weekend.  Going to order new u-joint, and boot.  Anything else I need? 

[longrider]

Nothing else really.  A bit of grease on the output splines.    Pull the drive shaft out of the final drive.  Clean up the pinion cup real god.  Check the splines in there.  If it looks good. Add a  small coating of moly to it and put it back together. Then do the final drive to wheel splines.  I use a bit of grease in with the moly on the wheel splines.  I've had the moly dry out on me in there.  Let us know how it goes

[Tfrank59]

I found my u joint bad during the regular rear end maintenance. Most of us hopefully take the rear wheel off at 10,000 miles or so and do this maintenance. The u joint removal and grease splines is part of the maintenance. Four nuts and pull the pumpkin and drive shaft, then remove the chrome brake cover and let the rear master cylinder hang. Pull the boot back and wiggle the the u joint back and out.

Mine was loose and I could feel it without a vise, never knew it from riding. I don't usually use a vise just my hands. I don't ride hard and downshift hard so hope I will not have trouble.The biggest deal is use the manual and follow directions, torque sequence exactly! Let us know if you have trouble as there are a few tricks to doing things easier.

I've done my rear tire three times now, and so the final drive maintenance with it, but I've never yet pulled my u-joint.  When I asked the guys on this forum if I should pull it to check it they basically said no, because it's good until it's not, and you'll know pretty quick when it's not.

[h13man]

I'd lean toward the rear wheel bearings. Mine went bad @ 32,000 mi./17 yrs. Age of the bearing shields/seals are a determining factor on both ends of the bike due to rubber aging thus letting the outside in.

[Harryc]

I'd lean toward the rear wheel bearings. Mine went bad @ 32,000 mi./17 yrs. Age of the bearing shields/seals are a determining factor on both ends of the bike due to rubber aging thus letting the outside in.

Anyone here repack the sealed bearings on a Valk? I am going to do just that next tire change. It's pretty easy to get the rubber covers off without damage.

[Valk-Obsessed]

Well, I got the U-joint out today...it's toast!  I'll post pictures soon.  Quick question...this time when I removed the final drive, the shaft stuck to the u-joint side, and was not in the pinion cup...I'm guessing I didn't put it back into the pinion cup properly last week.. ???  How does the shaft go back into the cup?  I know it was it took some effort to get it out the first time.  Wondering what I did wrong...

[Valk-Obsessed]

[Valk-Obsessed]

Geesch!  Sorry for the huge size of pics, need to resize those.

[Valk-Obsessed]

[hubcapsc]

Well, I got the U-joint out today...it's toast!  I'll post pictures soon.  Quick question...this time when I removed the final drive, the shaft stuck to the u-joint side, and was not in the pinion cup...I'm guessing I didn't put it back into the pinion cup properly last week.. ???  How does the shaft go back into the cup?  I know it was it took some effort to get it out the first time.  Wondering what I did wrong...

Sometimes the shaft is hard to yank out of the final, I guess it gets hung on
the C clip until you wiggle it right....



After you yanked yours out, was the clip still on there? This particular time mine was
REAL hard to pull out...



My pictures show worn out parts, what did yours look like?

Anywho, once you get everything back together I don't think the shaft has
any room to slide back and forth, or any other place to go other than the
right place. Maybe your shaft being stuck in the u-joint had to do with
your u-joint failure?

-Mike

[Valk-Obsessed]

thats what I'm hoping. My shaft and cup splines look good.  The first time I ever took it out awhile ago,  they were dry and there was red powder in the cup...I don't think the previous owner had ever taken it out.  Thanks to this board, I try to stay up to date on drive line maintenance!

[Tfrank59]

Well, I got the U-joint out today...it's toast!  I'll post pictures soon.  Quick question...this time when I removed the final drive, the shaft stuck to the u-joint side, and was not in the pinion cup...I'm guessing I didn't put it back into the pinion cup properly last week.. ???  How does the shaft go back into the cup?  I know it was it took some effort to get it out the first time.  Wondering what I did wrong...

The shaft shouldn't be stuck tightly in the u-joint.  It should be able to slide along the straight spline (as the swing arm travels) and stay pushed rearward via the spring that's on there.  take a good look at shaft splines on the u-joint end--if they're buggered then you'll need to replace the shaft as well.  As far as the c-clip on the pinion end, many on this forum say it's unnecessary but I have it on mine and it holds the pinion in the cup.

[Valk-Obsessed]

Looking on the parts fiche for the swingarm, I see a part at the end of the shaft that mates with the UJoint, called an "oil seal"...I never saw one come out with my drive shaft....I seem to be missing it.  I wonder when that happened.

[Tfrank59]

Well I think the oil seal is going to be on the pinion end. did one come out on that end of the driveshaft?

[Valk-Obsessed]

My bad...I see it on the Pinion in.  The fiche shows it near the U-joint end...so I was a little confused.
Thanks for setting me straight.

[Tfrank59]

Right then

[Valk-Obsessed]

Update:

Operation U-Joint transplant was successful.  I did have some issues with the boot, but went back to re-read some threads on it.  Using the "folded back sock method" worked like a charm.  The bike rides so much better now!  Thanks again for the tips, and advice!