To Much Transmission Backlash on GS550

[Roadwarrior]

Here is my problem. My 1978 GS550 has way to much transmission backlash. When I bought the bike it had arround 15000 km (9375 miles), and it had no sighns of abouse, or hard use. In first gear the backlash is verry bad, when I come to a stop and let out the clutch to pull away again it lets out a loud hard clunk. In first gear if I back off the throttle, then give it throttle again it lets out a loud clunk. The backlash gets better as I move up through the gears, by forth its acceptable, and in sixth I don't notice it at all.

The chain is adjusted proporly, and the sprockets are tight. With the bike on the centerstand, and the transmission in 1st, I can move the wheel back and forth more than 2 inches, more like 3. Riding the bike in traffic (what I do most of the time) is not fun.

What do you guys think it can be? To much factory tolerances? I bought a transmission off of ebay, but I don't want to rip my transmission apart, on an otherwise nice running bike unless I have an idea whats wrong. Could it be the countershaft? the mainshaft? Could the clutch basket be worn?

PLEASE HELP

[hungryman]

Since the chain is ruled out, I would suggest taking a look at the clutch. It's far easier than splitting the cases, and you need to remove it first anyway!

Check the springs on the back of the clutch hub.

[Roadwarrior]

Bump

Does anybody else have any idea what to look for?

[rkubik]

backlash

Another cheap & simple thing to check is the condition of the drive cushions on the rear hub (#15 in the image). These are rubber bumper kind of things where the rear sprocket engages with the hub, and collapse over time on many bikes.



Wiggle things around to check if there is excessive play in this area. You can also check it by taking the rear wheel off and trying to move the sprocket back and forth while holding the wheel steady on the floor.

If you can't or don't want to get new cushions, I've heard of people shimming them sucessfully too.