Drive Train Slop

[wingnut]

OK the E3s that I put on back in 06 have worn to the point they scare me so off they have come. While the rear is off I have pulled the FD so as to get to the drive shaft splines which were greased last time the tires were changed both on the ujoint and rear coupling. I see some polish marks on the rear of the drive shaft teath and slight wear on the ujoint side.

There dose not seem to be excessive slop in the FD and the Ujoint feels ok but when the bike is assembled, in gear on the center stand, there seems to be a lot of play when you rotate the rear wheel. I have no trans problems other than clunk when shifting, Bike has around 45K in milage. So where do I look for the slop? Middle gear, clutch? Thanks

Dave

[BA80]

There will be some play simply due to the fact that there are 3 sets of gears and the primary chain between the engine and the rear wheel. Most likely your feeling the play in the primary chain. that is usually a bit loose feeling without the engine running. Not a lot you can do anything about that without splitting the cases.

The other possibility would be the middle drive which seems to be the weakest link in the drive train. There will usually be metal shavings in the middle drive oil if there is a problem there. Since I assume you've checked the splines on the drive shaft and the u joint and they appear to be ok and no slop, my suggestion would be drain and refresh the middle and final drive oils and check for shavings and if you find none refill and ride!

[WSL91]

My 79 has a lot of slop between accelerating and decelerating. Much more so than my 82. I'm going to replace the final when I pull the swing arm (for painting and bearing inspection). I installed an 850 final in my XJ that has 10k miles and I saved the final drive. It's going in the 79 as it has ~50k miles. If that doesn't tighten it up I'll look for a low mileage middle drive. I'd rather swap parts then be setting on the side of the road somewhere.

[CaptonZap]

OK the E3s that I put on back in 06 have worn to the point they scare me so off they have come. While the rear is off I have pulled the FD so as to get to the drive shaft splines which were greased last time the tires were changed both on the ujoint and rear coupling. I see some polish marks on the rear of the drive shaft teath and slight wear on the ujoint side.

There dose not seem to be excessive slop in the FD and the Ujoint feels ok but when the bike is assembled, in gear on the center stand, there seems to be a lot of play when you rotate the rear wheel. I have no trans problems other than clunk when shifting, Bike has around 45K in milage. So where do I look for the slop? Middle gear, clutch? Thanks

Dave

All of the above. Tolerance stack, I think it's called. As a point of reference, my 80G, with the 850 final drive, has about two inches of slop between the stops, measured where the tread ends on the side wall.
The bike has 36000 miles on it, and the final drive and middle drive both have lash within specs. (Both are at the looser end of spec, but still within.)
Like Greg says, fill it with clean oil, and ride it. CZ

[wingnut]

Thanks guys. I think I'll pull the middle gear and check it for lash. I have no issues with it but the old girl is getting to middle age so it can't hurt to see if its in spec and that the splines are in good shape. I pulled the clutch cover and everything in that beast looks good. If eveythimg checks out its a refill with mobile 1 gear oil for the middle gear & FD then off we go.