[JerryH]

Glad you got it. It can be a pain to get the U-joint, engine output shaft, and driveshaft together, but there is a lot more room to work on the GW after you pull the rubber boot back than there is on most shaft drive bikes. I would replace that oil seal. Even if it looks good, if it leaks it can allow the oil to drain out of the final drive housing and into the swing arm. Other than a problem inside the final drive, the main cause of the clunking sound is the aforementioned output splines on the final drive, that engage the driven flange on the rear wheel. That should be lubed good with moly paste whenever you take the wheel off to replace a tire. And if that is worn (which pretty much ruins the final drive assembly) I would check the splines on the driven flange as well, they may also be worn, and if they are, they can cause rapid wear of the good splines on the final drive. The driven flange is pressed into 5 rubber dampers on the rear wheel. It can be pulled right off, though it usually requires a bit of persuasion. Check the rubber in the rear wheel as well. If these are bad, there is no easy way to fix them, they are molded into the wheel. Good thing is they rarely ever fail.