MisterX Posted January 29, 2006 Posted January 29, 2006 Hi Guys, Thanks for helping me out last time. TDM is running like a dream with the exception of a very nasty grinding noise coming from the gearbox when I accellerate in 3rd. I have accepted the fact that my gearbox is shot and fully intend to do a strip and re-build in the summer however I need to ask a few questions. Firstly, how easy would it be to do the strip and re-build for a first timer? I will not be pushed for time as I wont need the bike until next winter so that would give me plenty of time to complete the task. Secondly would it be easier to purchase a new engine and swap them over? One of the reasons that I dont want to do this is that I know the engine I have is good and whats to say the engine I replace it with has gearbox issues also. I understand that these early gearboxes aren't that good anyway (the worst on any bike I have had). Finally, I am still using the bike on a daily basis but just skipping 3rd every time I change up. Will using the bike in its current state make things worse i.e bits of broken up 3rd gear floating around the engine. Many thanks for you infinite wisdom, Rob, (MisterX) 1991 TDM 850
szzol Posted April 13, 2015 Posted April 13, 2015 Hi. Did you fix the noise problem with the 3rd gear? I just bought my TDM and I have the same problem. It's pretty annoying. Plus, I don't know why it's happening.
KevtheRev Posted April 13, 2015 Posted April 13, 2015 The noise from the gearbox could be due to a worn bearing getting ready to bail out , which could lock up the engine . Or you could have worn or chipped teeth on the 3rd gear pinion (cog) , which could also fail and lock the engine and/or break the crankcase . I hate to be the bearer of bad news but safety is paramount . You wouldn't have to be in 3rd gear for either of these scenarios . To fix the gearbox is a full stripdown unless the crankcase splits horizontally , in which case you may be able to turn the engine upside down and get at it that way .( I'm not familiar with the TDM 850 ) . The quickest and cheapest is to replace the whole engine with a good second hand one if you can find one . Maybe a rough one with a decent engine which you could try before handing over any cash . Best of luck man !
szzol Posted April 14, 2015 Posted April 14, 2015 Thanks for your answer. I would bet on the chipped/worn pinion. I guess if it would be a bearing, that should make the noise constantly. For now i try not to use the 3rd gear. I hope this way i can avoid doing harm to the gearbox until i can go to a mechanic. It will be a big job disassembling the engine to find out what's the problem.
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