When the bike is on the center stand and I turn the rear wheel by hand, there is a rattle which originates from the bevel gear. At least I think it does. It sounds a lot the same as a badly worn chain and sprockets would. I noticed the rattle already soon after I got the bike, but didn't think much of it then. Yesterday after a ride I got worried because it sounded louder than before. However, this morning when the engine was cool it was back to 'normal'. I'm pretty certain that it is not the splines as I have lubed them and they looked good, both front and rear. You can listen for a sample yourself HERE (http://www.youtube.com/watch?v=tRDqJ23dJWg).

Is this something I should get worried about or even react to immediately?

That is not a sound you want to hear, something is getting ready to let loose or already has. :doh:

First thing to check is the universal joint, push back the rubber boot on the bevel gear and you will see the joint. While you are there try to move the shaft comming out of the bevel gear because it sounds like a bearing is bad and putting the gears in a bind. If that bearing is OK it could be the one behind the chrome and black on the bevel gear.

Yep, that don't sound good. I wouldn't be riding until you get that figured out and fixed!

Pulled the bevel gear and found that the drive gear double row bearing was bad.

http://i393.photobucket.com/albums/pp18/pappa_stuff/bevel.png

I will get on the phone tomorrow and try to locate a new bearing. I want to get it asap. The bearing is Koyo 5305. If I don't find one do you know if there is a similar SKF bearing I can use? Well, the SKF salesmen should know..

The single row ball bearing next to the damaged bearing seemed good, but do you think it would be a good idea to change that too?

Do I need to worry about the shims because of changing the bearing(s), or just put back everything as they were?

And finally a question about the drive shaft u-joint. I didn't feel any play in the joint, on the contrary it felt quite stiff. I might replace it if it is replaceable. Is it? I had a close look at it and have no idea how it could come apart.

If your in there replacing bearings, it won't hurt to take care of all of them. The gear lash should also be checked after you change the bearing to be sure it still has even tooth contact.

I think I'll leave the driven gear bearings alone. I had enough trouble getting the drive gear nut off and the double row bearing out.

By the way, that drive gear cap (looks similar to the swingarm caps) does not come off undamaged. I tried, but in the end it was easier to pry off the outer bearing casing from the bearing.

Pulled the bevel gear and found that the drive gear double row bearing was bad.

http://i393.photobucket.com/albums/pp18/pappa_stuff/bevel.png

I will get on the phone tomorrow and try to locate a new bearing. I want to get it asap. The bearing is Koyo 5305. If I don't find one do you know if there is a similar SKF bearing I can use? Well, the SKF salesmen should know..

The single row ball bearing next to the damaged bearing seemed good, but do you think it would be a good idea to change that too?

Do I need to worry about the shims because of changing the bearing(s), or just put back everything as they were?

And finally a question about the drive shaft u-joint. I didn't feel any play in the joint, on the contrary it felt quite stiff. I might replace it if it is replaceable. Is it? I had a close look at it and have no idea how it could come apart.

Went through this a few months ago with another member from finland, He could not get the 5305 bearing he had to get a 3305 bearing from Emerson a (ROLLWAY) bearing. You can also use the FAG 3305 bearing.

Here is the link:

http://www.vn750.com/forum/showthread.php?t=9211

You were right (again) Lance, Koyo 5305 is not stocked in Finland. But the Koyo seller knew to recommend Rollway 3305 instead, points for him for that. I will get the bearing tomorrow.

Glad to help and good luck with the repair. Keep us posted when you get her fixed. :smiley_th

The rattle is gone! It took me a good 5 hours to put all back together. A professional would surely have done it much faster, but I'm not a mechanic and my tool assortment is limited. I tried to check the bearing housing gap the best I could, but I don't have such thin feeler gauges as required. All I know is that the gap was too big after changing the two bearings, so I left out the thinnest shim. Also I don't have a dial gauge + accessories to check the gear backlash, so I left the original gear shims in place. There is a little backlash, but I don't know exactly how much. Also checked the tooth contact pattern. Did not have checking compound, but since the service manual says that the compound consistency is about same as tooth paste, I used tooth paste (isn't that appropriate!). Got satisfactory results in my opinion.

The hardest part was to get the bevel gear back in place. I'm afraid a few PERKELE-words escaped my lips while putting it back. The first time the drive shaft slipped off the splines and I didn't notice. Yes, the bevel gear goes there, but the drive shaft gets wedged real tight in the shaft tube so that it won't budge. The second time I succeeded, but the whole process took so long that I'm afraid the liquid sealant dried too much before I finally tightened up the housing bolts. Well, we'll see if it leaks - I hope not.

Boy, after that job hot sauna and cold beer felt really good!:smiley_th