?? about Ujoints.

[ClarkGriswald]

Hi everyone, Ive been searching around and this seems to be eluding me..

Even in the clymer manual, why does it not say anything about that ujoint??

I most recently come from the jeep world and UJ's are constant maintenance. Arent we supposed to lubricate them at some interval?? please dont tell me they are non lubable (except for dismantling). If thats the case then I need to get that thing outta there and find out.

I got so good and changing them things I was gonna go around the country like "johnny U-joint" (appleseed) changing em for people hehehe.. Especially the front axle ones those are fun. Now I have a bike with one and I cant help but think about it.. and I think I mabye feeling it thru the footpegs at slow/medium speeds. Just a slight rythmic pulsation that Im thinking would be about the right tempo, although I admit I dont know what kinda rpms that shaft is doin in relation to engine/axle. It is not the normal clunking or squeeking that Ujoints do when they are going bad, but seems like its in the driveline.

Other possibility is that my rear brake rotor is doin that, as it does rub a tiny amount at one point in its travel.

Guess I could run the bike in gear on the centerstand and find that.. But just wondered about those Ujoints.. I dont like having an "unknown" like that.

[bikerphil]

u joint

There is no grease fitting on the u-joints. I've never heard of one go bad on these bikes. I once had a bad vibration, thought it was the u joint, turns out the three 6mm allen bolts on the middle drive were loose. These are the ones forward of the u joint by the yoke. I guess the joint could be lubed as they have inboard c clips.

[trbig]

I think the main thing with these is that they are protected from the elements by the rubber boot, so the grease isn't getting washed out. Kinda like when your tie-rod ends on your vehicle will last a long long time... until one overzealous grease monkey packs the boot so tight it rips. The water and debris make it in, and within a couple years.. time for tie-rod ends.

But Mr. Appleseed... you make it to Oklahoma, and you can feel free to drill and tap mine for a zert!!


Tod

[ClarkGriswald]

I should have remembered the rocks, er boot.

Im sure next time I am in that vicinity of teardown I wont be able to resist tearin it down. Are they standard ujoints available anywhere or some funky yamaha thing that noone else makes?? hehe

[bikerphil]

uj

These are a dime a dozen, I see 'em on Ebay for $5-10 all the time. Someone once said (can't remember who), that a older Toyota uj works, but i can't remember the year + model. If ya need one, just holler, got about 3 spares.

[ClarkGriswald]

Thanks for the info guys, I dont know that I even have a prob but have been wondering about that.

[Ivan]

NAPA can cross reference U joints by the diameter of the cups and the width of the cross. I used to do this all the time when i was wrenching on hotrods and had no idea id the u joint came from the nova body or the camaro driveline and that sort of situation.

[Shappers]

As Bikerphil says, these UJs do come apart.

Pop the C-clips, push them out using a vice and some sockets. Clean out the old grease then repack them.

The needle bearings themselves also have a small oil seal around the edge of them so be careful if you go digging with a screwdriver!

[ClarkGriswald]

I have it down to a science. I used to do the vice and sockets thing until I bought a 4 wheel drive ball joint press kit.. basically is a giant C clamp (really thick). This works even better for ujoints cause you can clamp "it" into the vice and it comes with all sorts of adapters that help. Now on an automotive shaft that has been apart in recent times.. You can just use some PB blaster combined with some tapping with a hammer.. and then just put an impact gun on the end of the giant c clamp and press em right out/in.. really fast..

But anything that is years old requires delicate care.. if you bend up those yolks you got balance probs and possible fitting of the cross probs.. on something like a bike I think Id be quite carefull not to manhandle it too much.

Also like many things, that giant C clamp has a really good sound to it.. better than the best triangle. so if you balance on one finger to where you can grip it and mute and let it free again to ring.. you can do a really good version of that "suspense music" in detective/cop shows. Ya know when they are sneaking around in the dark doin something.. or up to mischief..

[Bigleo]

Hi Clark,
Two years ago I started getting a vibration at 5500 rpm, that went away at about 5700. I suspected the U joint, so when I had the swing arm out to paint it, I took a look at the joint. What I found was that it was tight flexing it one way and OK moving it the other. I had a spare joint, so as the previous posts have described, I took the spare apart, greased it with marine wheel bearing grease, and put it back together. The vibration was totally cured. The bike is dead smooth now, you can hardly detect that the engine is running at 6000 rpm.
good luck with yours,
Leo

[TopCatGr58]

Hey Clark,

Take lots of pictures and do a WRITE UP so we can have another cool tech tip!! You sound very experienced with these things, so should be some good info to share with others!!
T.C.

[ClarkGriswald]

Nothing like fresh grease on the hands.

Got the swingarm off, sittin in the sun drying before I give it a fresh coat of black. Guess I never thought about how small that ujoint would be. Mine works really well and I can tell its in good shape. I may still take it apart just to lube it with some fresh sauce. If I do I'll take some pics. I swear its almost as fun working on this thing as riding it. (remember I have 3 cyls below spec .. 115,115,112,144 yesterday, so its not like it runs anywhere like an 1100 should although it runs nice and smooth and reliable I know its way below being right)

So I just keep fixing/lubing/adjusting stuff and making test runs.

[ClarkGriswald]

Well I couldnt resist lubing that while it was apart.. I got pics of the whole process (too many) and heres how it ended up.. Im still outside working on it so this is all for now.. then Ill work on organizing it.