R1200 G/box
 

Hi all, help required please.
I have recently bought a 2005 R1200RT & have a g/box fault.
When in gear & on the stand there is about 120-150mm of lash at the rear wheel. To ride smoothly at low speed requires contant clutching.
I have removed & checked swingarm/driveshaft & final drive & all ok.
I have now removed the g/box to attend to oil leaks from input & output shaft seals.
When in gear the input shaft can be turned about a 1/2 turn before the output shaft turns ( i.e lots of lash ).
I have now opened up the g/box but can find nothing untoward.
Anyone got any ideas?

Cheers, Chris

Might be a stupid question but just in case...Have you checked the throttle play?

I had what I thought was a lot of play associated with the FD but a simple adjustment of my throttle cable on the handlebar was all I needed... probably wishful thinking though in your case.

Hi Turbo, thanks for your input, well according to a BMW mechanic the g/box on these models are all like that. I have stripped many g/boxes over the years and have never come across one that has play through the drive. Apparently its to make selecting the gears smoother. Good job I had to take the box out for the oil leaks then.

So I'm told the running problem is probably caused by the throttle bodies out of balance, which would make sense.

Oh well better start to glue it back together again...

Hi Chris,

Just following up with your problems, how did you get along? Can you post any more information here incase others experience the same thing.

Not sure about the exact play at the rear wheel as it doesn't seem to be listed/reported/documented by BMW or the like.

Why was there an oil leak? Did you over fill the Gearbox oil? Usually if there is a leak on the clutch this is because the gearbox oil is over filled and puts presure on the rubber seal with the clutch and oil drips through.

Have you adjusted the throttle bodies? Did this help?

Cheers!

Hi Turbo,

Sorry for delay replying, I've been working away.

Well the bike is now back together and running fine and without the oil leaks.
I bought the bike cheap because it had some faults, so don't know if the g/box had been overfilled. The input & output shaft oil seals were leaking along with the clutch rod seal.

I've adjusted the thottle cables and it runs fine now.

My friend has just bought a GS1200 and it has about the same amount of transmission play at the rear wheel, so thats reassuring.

Cheers, Chris

a quick test for this is to select top gear (or 5th) and you should have a one to one ratio between the input shaft and the output shaft

Hi Jaythro,

Not sure what your quick test is for, but if you're referring to the lash in the drive, it's because the dog teeth for each gear engage into slots and not other teeth like most g/boxes. The higher the gear the larger the slot. Seems a strange set up, but the slack in a chain drive does the same.

Regards, Chris