Bonneville America Forums Forums Technical Forums General Tech How to check rear wheel bearings?

I'm still trying to sort that cyclic vibration. Today even tho i haven't recieved my new sprocket i did a thurough check on the old one and it appears to be find. Hopefully somehow that WILL end up being the problem, but if not i'm now thinking about wheel bearings. i'm considering the possibility i may have overtightened the axl before i got a new torque wrench. I know i tightened it way more than i should have after seeing what 62 foot lbs feels like on it.

So what i need to know is if there3s a way to check them w/o removing them? They say if you remove them they need to be replaced, and if they're fine the last thing i want is to have to grit my teeth as i look at triumph's price on them, cuz you know how that goes ! So how can i check? I can tell you that with the wheel on there is absolutly no play or slop anywhere except a slight maybe 1/8" in the drive rubbers. besides that the wheel spins smoothly and appears perfect. But i assume that bad bearings won't necassarily show in tests like that.

EDIT: it just occured to me the final drive mainshaft or whatever it's called could have a bad bearing. Do the cases have to be split for that and how would i check that?

Most of the time,daz. If a bearing is bad it will have ruff spots that you can feel when turning it. But that depends on just how bad the bearing races are. You could probably feel ruff spots more easily with the wheel removed and turning the inner race by hand. But,because these are seal bearings you want be able to tell anything visually. If a bearing has only slight pitting or low grease level it will be hard to tell indeed. As new as your bike is I would thing it highly unlikey unless it was bad from the factory or as you stated sevearly over torqued. Again I would think it unlikely.

Before i thought of the final tranny bearing i was worried it would be a wheel bearing........now i'm kinda hoping it IS !

I recall turning the bearing by hand and feeling nothing unusual, tho maybe i only did that with one. This is driving me absolutly nuts.

Daz, I went back and read your orginal post on the vibration and you stated then that it only occurs when the engine is engaged,ie it goes away when you pull in the clutch. You know these engines have balance shafts to help reduce vibrations, but they don't totally eliminate them. Could be the rpm and engine speed you notice this is just a harmonic frequency that vibration just occurs normally. You may be chasing a ghost. Just a thought.

No, it just started. i'm positive it didn't do this before because it's way too obvious to not have noticed. I'm trying to determine what could be causing it with consideration to the fact it happened right after i installed the wheels after getting new tires. One thought along those lines is that the last time i tightened the wheel before i got the tires i over tightened it and after releasing the tension to remove the wheels any distortion the bearings recieved is now showing up. Or after installing bthe wheels maybe i tightened the chain too much as the final bearing on the shaft the sprocket is on was damaged. In other words, things that could be related to my removing and reinstalling the wheel. Gotta be related because thats when it started. I've eliminated the chain, and the sprocket is due tuesday so that i think will be eliminated after checking my old one and seeing no problems. That doesn't leave a lot, and in fact the bearing at the shaft and in the wheel are all i can think of thats left. but if you have any ideas don't hesitate to mention them........i can use all the help i can get. by the way, i woulda thought Pat would have replied but it seems like he hasn't been replying to anything recently. Did he go on a trip or something?

Ok had not thought of this in a while because it went away. I used to notice a distinct vibration at a certain speed,higher than yours. I mostly noticed it on freshly paved highways. Like yours, I could pull in the clutch and it would stop. As my tires wore futher I just stoped feeling it. Or maybe I just got used to it and they haven't paved any roads around here recently either. I since have put on a new set of metzler's and went with a differnt tread pattern on the front than the orginal. I'v not experinced it since.

Start by examining the tire for uneven wear. Loose or binding bearings often cause a 'cupping' effect in the tread wear.

Lift the rear wheel off the ground and turn it by hand to see if there are any rough or binding spots. If there are, undo the brake caliper mounting bolts, tie off the caliper away from the disk and try again to see if the problem is still there. If it went away, you may have a warped disk or sticking caliper.

If it is still there, loosen the chain adjusters, kick the rear wheel all the way forward, disengage the chain from the rear sprocket, retighten the axle nut and try it once more.

If it's no longer there, give the wheel a light shake to test the bearing preload.If you can feel a clicking in the wheel as you move it, the preload is too low or you have a bearing problem. If the wheel doesn't shake at all, then your problem is in the chain, sprockets or elsewhere.

If it is still there, make sure nothing is touching the rim or tire that might cause the problem. If all clear, you have a bad bearing.

Thanks. I've already eliminated pretty much everything you mentioned. Brakes are definatly fine and not dragging or warped rotor. Also, remember, i have new tires and chain. It was after the tire swap i noticed it, tho not till about 20 miles later. I checked the wheels, tires and sprocket for trueness by mounting a pointer close to them and spinning to find any varience. They were all even straighter than i though was possible. Not even a slight varience i could detect in tires wheels sprockets or wheel play. Cush drives are good too with only 1/8" play. And i have a new sprocket on the way anyways because i bought one with the chain which turned out to not fit. So the correct one is on the way. Front sprocket is a 17 i put on just recently so i'm sure it's fine and it looks it.

So new chain, rear sprocket is straight as an arrow, front close to new, tires and wheels very true, brakes/rotor fine, alignment fine. (plus tried it many ways using frame to align, nothes, straightedge) The big scare now is the final drive bearing. No way i'm having the cases split. That will cost me 1/2 of what the bike is worth and achances are they'll screw up the mating and i'll start leaking. I don't trust them as far as i can throw my bike !

With your ride on her sidestand, grasp the rear wheel and try to move it between the drop outs. That would be 90 degrees to the dropouts. Any play at all and one of three bearings may be bad. Spinning the bearing works too, but you have to do as greybeard wrote. I had a bearing go bad in the rear wheel. Forget which one it was, but I replaced all three and the seals too.

Daz, are you sure the shop that mounted your tire balanced them right?........Angelis