Paralever drive train

Fudmucker

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I was preparing to drain my '96 GS gearbox oil the other day.
I had the bike on the main stand with the rear wheel off the ground.
I started the bike and ran through the gears to warm up the oil to drain better.
I was not at all happy with the shudder and whiplash on the drive train...!

The bike has done 75 800kms - most by previous owners.

Time for a driveshaft replacement / refurbishment?
Options and recommendations please for who to send it to?

PM please if you prefer.
 

EtienneBnk

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What does it feel like when on the road? I suspect the rear wheel off the ground has something to do with the noise and vibration and the like . .
 

Jughead

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With the rear wheel off the ground and the the bike running in gear, it is quite normal to have a huge amount of backlash and shuddering. It sometimes helps to apply a small amount of pressure to the rear brake pedal to create some resistance for the gearbox/driveshaft/final drive to act against.

By far the best way to warm up the FD oil is to take the bike for a 15 minute ride. If the bike feels smooth without any clunking while riding, you have nothing to worry about.
 

Fudmucker

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The gearbox is drained. The oil came out the colour of tea with milk.
I left it for a few days to fully empty and it is now the colour of strong coffee.
There seems to be a light-coloured sludgy substance that has settled out...

Should I go normal gearbox oil or full synthetic...?
 

tulips

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The gearbox is drained. The oil came out the colour of tea with milk.
I left it for a few days to fully empty and it is now the colour of strong coffee.
There seems to be a light-coloured sludgy substance that has settled out...

Should I go normal gearbox oil or full synthetic...?
Water ingress, emulsified? Only way in is rubber sleeve on the speedo cable, rather replace that or fill with silicone, or tape up when washing . If it's really clunky when you refill and run its possible the output ball bearing retainer has rusted and collapsed, it is right there. Mineral oil as specified is more than good enough for the box. Good luck
 

tulips

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Water ingress, emulsified? Only way in is rubber sleeve on the speedo cable, rather replace that or fill with silicone, or tape up when washing . If it's really clunky when you refill and run its possible the output ball bearing retainer has rusted and collapsed, it is right there. Mineral oil as specified is more than good enough for the box. Good luck
Edit ....you would have noticed prior to this if the bearing was stuffed, it's very obvious
 

Welsh

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You should never run the final drive on the stand, the suspension is at the extreme of its travel and therefore so are the driveshaft UJ's running it will give you a LOT of backlash etc.

On the 11xx series, there is a breather on top of the FD if that gets submerged the cooling of the hot FD in the water will such water in through the breather.
 
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Another useful tip to stop water seeping into the gearbox through the speedo cable is to fill the rubber cover with grease.
 

Fudmucker

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One of the senior guys at the Great GS Gathering this year showed how he fitted a spark plug rubber cap onto the speedo drive cable above the OEM rubber grommet to reduce the chances of water ingress. I think I'll do that too.

The paralever diff also has the 'let-air-out-let-water-in' valve at the top.
You can mod that using a pneumatic coupler and a length of rubber tube to a suitable spot under the fuel tank.
 
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