Gearbox bearings

[collinsa]

Anyone had an issue with noisy bearings from gearbox at low speed < 15mph (25kph)
Was escorting a cyclist a few weeks ago on a charity ride and the noise made me think the bearings on the output shaft were shot. Sounded like crap
Problem is the bike sounds reasonably normal at road speeds
Honda tech took it for a ride and said that at 11 years old and 160km he considered it was normal and what he expected

[PastoT]

I have an 02 and haven't noticed any noise but will take note next time I'm out. in saying that I don't know the complete history from the PO and I have changed out the differential oil in the last year and a half. I notice the engine and tranny is quieter after an oil change. The back end only takes like 4 oz of fluid and since the bottle contains way more you might try a flush and fill. I'm sure if its low it would make more noise, but in the process you can eyeball the old fluid and see what if anything it contains (metal shavings, dirt, etc). I think atop the differential is a capped over breather than might allow small debris to enter, so changing the fluid and running a bit then repeating might be a good idea. Mine drained without issue and just discolored as I expected. This doesn't mean a bearing or a universal isn't worn and getting noisy. Certainly put your bike on the center stand and see how much play the rear wheel has and if it makes noise when you spin it. I'll bet someone can chime in on the amount of free rotation the rear wheel exhibits while in gear, too much could be an issue/indicator of wear. If you have real concerns or find something bad I'd find a low mileage trike take-off and swap the whole rear-end out. Still I'd try fluid change first, it doesn't last for ever.

[collinsa]

Thanks PastoT
The diff is fine and I change the oil every 12 months regardless of mileage - only takes a dollar or so of oil
My problem is with the gearbox - the primary drive shaft / first motion shaft - sounds like the bearing is running rough
I am not sure if I have just become overly sensitive to the noise because the Honda Tech says it sounds normal to him

Due for an oil change soon so I will check oil for metal filings

[PastoT]

Well I've always questioned the "techs" beliefs, a lot of sounds are subjective and it comes down to experience. I don't have that experience but I think I'd notice if something sounded off or changed with my own bike. I certainly understand your concerns, some would just turn up the radio! LOL Anyway if it come down to a repair I did read an article elsewhere and they were pretty adamant that rebuilding a rear end was more expensive with questionable outcome than replacing it with a trike take-off. I think replacing the whole shooting match would be my option if there was too much play in the rear drive, wheel, etc.; it would certainly be cheaper but that also depends on availability.

[collinsa]

Job done and back on the road
It was a combination of clutch springs. clutch chart bearing and a failing primary drive shaft bearing that was making all the noise.
The mechanic told me I had made a good call and the faulty bearing was scorched on the inner race and destined to fail
With me removing and replacing the engine and the mechanic rebuilding gearbox and clutch the parts cost me $US735 (all gearbox bearing and seals, new clutch basket, new clutch shaft and clutch plates) plus about of $US700 for labour I now have an as new bike good for at least another 12 to 15 years

Also took the opportunity to have the rear shock serviced and changed the fork oil in the front having previously replaced the for seals 15 month ago.

I own a hydraulic bike bench and had a mate weld me up a frame to hang the front end of the bike to remove the engine so with extra hands it was not a major drama.
Biggest issue was the engine hunting when restarted.
Removed the engine again and found a leak through the inlet manifold gasket and an injector with a bit of grit causing one cylinder to flood.
Once reassembled it started first try and having cleaned out the crap from the inlet manifolds due to using 91 octane fuel in is running better than ever.
Only plan to 95 or 98 octane from now on and will use a top end cleaner spray in through the throttle bodies at each air filter change

Used the stainless steel mesh from the air filter to cover the air intake ports and silicone self binding tape to cover the mesh ends

Few photos of the frame, engine intake and engine are attached

All in all apart from having to remove the engine the second time it was a very satisfying exercise to do the work myself and save so much $
because the Honda dealer quoted 26 hours to remove an replace the engine plus the additional work on the gearbox and clutch.

Ride safe

[WingAdmin]

Wow, excellent job! That was a lot of work, very glad you got that bearing sorted and the bike up and running right again! Good work!