paralever drive shaft

[(RIP) jings]

whats the signs to look out for for paralever drive shaft failure ive got a 1994 r80r with 37 thousand on the clock getting a lot of vibration through the bike around 4000 revs which seams to come and go it will be all right for miles then it.ll hit a rough patch for a minute or two if you decrease the revs it goes away just had the carbs rebuilt at scrimingers but the problems still there cheers ..mike.

 

[nick.ct]

If its a drive shaft problem it is more likely to be road speed related rather than engine speed related

 

[(RIP) jings]

aye thats a point it allways comes in around 80 mph

 

[nick.ct]

So, does it appear @ 80mph in both 4th and 5th gear. Your original post indicated it was related to engine revs.
As an aside, in the past I had a road speed related vibration on a R100GSPD at about 60mph. I was worried it was something major like a driveshaft problem, it turned out to be the rear tyre (Tourance) that had worn unevenly.

 

[cristhemuso]

I have replaced drive shaft and gearbox output shaft bearing in the past. You should spin the rear wheel and listen for any noises. The only noise should be the slight tap as the slack is taken up. Any other noises could be a shaft problem. Maybe best to ask an experienced tech to take a look. My bike still rode ok after some of the needle rollers had escaped!! It sounded a bit clunky but not too bad so definitely follow up. I knew the gearbox output shaft bearing was fubar when I tried to turn the output flange when the shaft was off and it was notchy. Mr Scrimminger fixed that nicely. Rear wheel made a swishing noise when I span it also. Also intermittent vibration through the foot pegs ususlly at slow to medium speed round corners. I thought it was rear bevel but it had zero slack and ruled that out.
I read the shaft nearly always gives up eventually!
Good luck

 

[Kenny]

The r100r and R80r drive shafts appear far more reliable than gs's...less angle on the UJ's etc

 

[(RIP) jings]

thanks for the replys going to junk the in line fuel filters first just had the carbs rebuilt but am going to get them balanced back tyre could do with getting changed so will try these things first then see if theres any change .spinning the back wheel on the main stand does,nt make any noises there is a little play befor anything turns but it is very little . btw does anyone have a gs paralever rear subframe fancy a single seat big rear rack only use the bike for doing winter rallies cheers ..mike..