U-Joint

[hoosier jaybird]

I'm curious, can the u-joint be replaced without removing the swing arm? Can it be inspected by loosening the cover boot, and what holds it in place on the output shaft? I have seen posts about the u-joint and the whole driveline system looks to be high maintanence. I have done the spline lube but haven't inspected the u-joint. My 99 has 18K so I wouldn't think there is a problem but for peace of mind I'd like to be sure. Thanks , Jay.

[MP]

Yes and Yes.  Although it is better to inspect pulled out.

MP

[Chrisj CMA]

All you can do is look at part of the U-Joint and maybe detect a pending catastrophic failure by the peel the boot back method.  To remove it (the only real way to inspect it) you dont have to remove the swingarm but, you do need to remove the rear wheel, final drive/driveshaft.  

The U-joint is held in place by spring tension from a spring on the front end of the drive shaft.  Once the final drive is tightened down the u-joint is "locked down" it can no longer slide off the output shaft.

After the wheel and final drive is off...all that is needed to get that thing out is to move some things out of the way like the rear master cylinder and some wires and it can be pushed off its perch and worked out between the frame and the motor, its tight but not real bad

[Squealy]

After the wheel and final drive is off...all that is needed to get that thing out is to move some things out of the way like the rear master cylinder and some wires and it can be pushed off its perch and worked out between the frame and the motor, its tight but not real bad

IMHO the worse part is getting the boot back on both sides....

[Jabba]

its tight but not real bad

Getting it OUT is EASY.  Getting it BACK in... a little tougher...

Getting the U-Joint boot back on?  Freaking TERRIBLE!!!   I have to make either Squealy or my brother do that for me.  I just CAN'T do it.  

That's why Squealy and I are a good team.  He can't get the final drive back in the swingarm, and get the driveshaft to mate with the U-Joint.  I do THAT easy... just can't do the boot.

Plus it's ALWAYS better to have a buddy there with you.

Jabba

[hoosier jaybird]

Thanks for the tips. Guess I should have asked before I did the spline lube.  ??? Jay.

[MP]

Thanks for the tips. Guess I should have asked before I did the spline lube.  ??? Jay.

Well, with only 18k on the bike, I would not worry about it at all.  Take it out next time, if you want.

MP

[Jess from VA]

This is helpful.  Click each pic to enlarge with written guidance.

http://www.rattlebars.com/mtz/ujoint.html

[Willow]

In reference to removing the U-joint to inspect it, how often do you experts think that's necessary?

The reason I ask is the apparent consensus that replacing the boot correctly is the most difficult part, and thus the most likely part to do incorrectly.

My opinion, and it's only worth half what you paid for it, is that incorrectly replacing the boot at the U-joint and thus allowing water into the swingarm may be a big factor in subsequent pinion failure.

That said, I've almost never removed and inspected my U-joints.  I may insert the driveshaft and wiggle it to see if I can detect any unreasonable play.

I've experienced no catastrophic U-joint failures ( I wish I hadn't said that aloud) although I have replaced one that seemed like it may have been on the way to a future failure.

[Jess from VA]

I have had a catastrophic Ujoint failure..... and having struggled with the boot for hours on end, I don't ever pull it off either.  I can only handle that much fun once every ten years or so.   

[Daniel Meyer]

If you buy a new boot it is MUCH easier to put on (only a few $$).

I've only inspected when showing others how to remove/replace. There have of course been some catastrophic/sudden failures, but generally they will give you plenty of warning.

Remember... Valk=Smooooth
If there are vibrations, wandering, shaking, or any other bad behavior that seems to be acceptable on other machines, well, it's broken. Find the problem and fix it.

[hoosier jaybird]

Jess from VA, thanks for the tutoral on the u-joint R/R.  It appears from other posts that the u-joint is not as critical for maintanence as the rest of the driveline components. Is that the consensus? Jay.

[Chrisj CMA]

In reference to removing the U-joint to inspect it, how often do you experts think that's necessary?

The reason I ask is the apparent consensus that replacing the boot correctly is the most difficult part, and thus the most likely part to do incorrectly.

My opinion, and it's only worth half what you paid for it, is that incorrectly replacing the boot at the U-joint and thus allowing water into the swingarm may be a big factor in subsequent pinion failure.

That said, I've almost never removed and inspected my U-joints.  I may insert the driveshaft and wiggle it to see if I can detect any unreasonable play.

I've experienced no catastrophic U-joint failures ( I wish I hadn't said that aloud) although I have replaced one that seemed like it may have been on the way to a future failure.

my philosophy (FWIW) is this:  You were either blessed with a good u-joint or a bad one. If you got a bad one you will know soon enough and have to deal with it.  If you don't have to deal with any vibration problems and you are getting close to 100,000 miles then, while you have the rear wheel off, CHECK IT.  Any rotational play whatsoever and it should be replaced.  Over 100,000 miles on the original u-joint, Id check it at every tire change

[Jess from VA]

Welcome Jay.

There really is really no maintenance to perform on a Ujoint.  Other than checking it for kinkiness or physical damage inspection. And if you have no symptoms to speak of why do it? (except like Jeff says after 100K or more) It has no grease zerk (it probably should, and I seem to remember someone adding one).

After I replaced one, I later hit it with a penetrating oil spray in place under the boot from the side cover, but figure that lasted for a week or two.  Then hours getting the boot back on.  I won't do it again.  

Daniel said total instant failures are rare and you get some warning.... mine started making grinding and clunking noises, and I limped 20 or so miles home after finding a slower speed where it minimized the grinding (like 35mph) (and I knew I wasn't leaving again until it was fixed).  When I pulled it out, it fell apart.  One Ujoint retaining ear had battered itself to pieces/chips.  You generally feel it thumping in the pegs or an intermittent grinding but it will not give you weeks' to get worse.  Maybe a couple short rides more or maybe in two hours.

I think you leave it alone until/unless it breaks (unless you want to pull it all out at a tire change).  Absolutely get a spare to have on hand and maybe take along on trips.

I think I will order a new boot too.  Anything to make that bastard go on easier is worth it!!

[Oss]

I noticed a grinding noise when I let off the throttle in 4 or 5th gear

Like Daniel said, if you hear something then it needs further investigation

I had 81000 or so on the bike

Unfortunately its been one thing after another since then

Sure am hoping to get my bike back for the Memorial Day ride, I am startin to get nervous
between the bead leak, the leak from the rear drive unit and wondering if I have my front brakes properly done

Good luck and enjoy riding your almost new Valkyrie

[Mildew]

I'm glad to hear it's rare. I imagine those things are like bearings. The new one might be worse than the one you've replaced if you replaced it just because.

[Valkpilot]

I'm glad to hear it's rare. I imagine those things are like bearings. The new one might be worse than the one you've replaced if you replaced it just because.

There was a period during which u-joint supply was limited.  This drove up chatter about u-joint failure dramtically, and made people think that failure was a common thing and about to happen to them.

Complete failure is actually pretty unusual.

[Mildew]

  that's a funny thread. I used to ride mine pretty hard. I had the front end up many times. Straight up. Those things are pretty stout. I've also pulled a trailer for many years. Loaded heavy at times.

[john]

   " My 99 has 18K so I wouldn't think there is a problem "                       

[Mildew]

My Speedo cable broke at 63,000. I probably have over 100 by now but I'll just buy one when it fails if that would ever happen