clunking noise at low rpms

[ronnie]

Hi, I have a 1982 GS GL with about 10,000 miles on it. Not too long ago, it began a loud clunking noise on left lower side of engine at take off. I have noticed increased vibration also. Motor cranks right up and runs very smooth, shifts great also. No noise at idle or reved up when in neutral, or when clutch lever is pulled in. Only when under power at low speed. Thanks for any reply or advice.

[Nessism]

Could be the rear splines are failing and sending vibration up to the engine though the shaft drive system. Other possible thing is the clutch hub nut is loose or the secondary reduction gears are failing. The wheel spline and clutch hub nut repairs are easy, the secondary gears, less so.

[ronnie]

found the problem

I finally got some time to work on my bike, I started at the rear wheel, splines looked ok, final drive was ok, best I could tell. But it was not till I pulled the swingarm and prop. shaft that I found out what happened.
the shaft broke right at the u-joint. The universal joint flange, washer, and nut and piece of shaft is still attached to the u-joint. I took out the 4 bolts to the driven gear housing and loosened three nearby crankcase bolts as "per manual", but housing will still not budge. The shaft broke right at the splines of the secondary driven gear, which is still in place. I searched the site for a similar problem, and found that (legaleli) had the same problem, matter of fact, he posted a picture of the broken shaft at the gear housing. I sent him a message to find out how to pull the remainding gear assembly out of the crankcase, but I wanted to let you know I was very thankfull for your fast reply and very helpfull advice. I am looking forward to getting more involved with the site in time, and want to share and help others. Any advice on getting the remainder of the driven gear shaft out would be appreciated. Thanks again.

Ronnie

[spchips]

You might have to loosen up more of the 10mm bolts that run around the crankcase. Also, you didn't miss the larger 12mm bolts that are meant to hold this in place, did you? They are very long if I remember correctly.

There is nothing else holding it in as far as I can remember.

[ronnie]

Thanks spchips! That worked, now Ive got to try to clear the frame, even with the swingarm removed, I still might have to pull out 3 of the motormount bolts and pick the engine up a little in the rear to clear it. Thanks again, and nice quote. ronnie

[BassCliff]

Hi,

Is this the piece that broke?

Bevel Gear Shaft Repair
(by Mr. Zooks)


Thank you for your indulgence,

BassCliff

[ronnie]

Thanks so much BikeCliff! And thank you Mr. Zooks! I am an unemployed ex-Commercial Diver/Land Surveyor right now, but maybe some of the money that I will have saved, I can make a small donation toward the worldwide mission for hunger. Also, maybe some of the time all of you folks have saved me, I can get more familiar with this site, and be helpful myself in time. I like your quote, and your own website is unbelievable. I am so grateful to you all!

[legaleli]

Thanks so much BikeCliff! And thank you Mr. Zooks! I am an unemployed ex-Commercial Diver/Land Surveyor right now, but maybe some of the money that I will have saved, I can make a small donation toward the worldwide mission for hunger. Also, maybe some of the time all of you folks have saved me, I can get more familiar with this site, and be helpful myself in time. I like your quote, and your own website is unbelievable. I am so grateful to you all!

The tolerances between the frame and the housing are REALLY tight. I ended up grinding down some of the side of my housing to get it to clear the frame...