M6800 1-2 gears out, 3-4 work ok transmission broken

[KFhunter]

Looking for resources on fixing/rebuilding the 4 speed transmission. It's mechanical 4 speed with high/low lever down by left hand and fwd/neut/reverse lever up by the steering column.

While in 2nd gear the shift lever started wobbling back and forth bad in both high and low 2nd gear, hard to hold onto so I was using that gear cluster sparingly finally it went bang and I heard grinding noise. fished planting using only 3 high and 4 low which sucked.


So now I got some time to dig into this thing see what it would take to fix. Not finding much online, I know Kubota will charge *a lot* to fix.

She blew at the 792 hr mark. Oil levels good and clean looking on all the dip sticks, I planed to change all the hydo oil out at 800hrs and do a big service with all fluids change out.

 

[rbargeron]

If you unbolt the shifter plate you may be able to get an idea if what's failed. With one rear wheel jacked up the trans can turn while you check it out. Likely the tractor will need to be split for the repair. The WSM and parts list will help you plan the job. With loader detached, some of the subframe may be able to stay in place, depending on if front driveshaft can be taken down.

Back in 2001 there was a thread on TBN about M6800's popping out of second gear - TBN member JRP reported about it here.. Not sure its the same issue but it could be related.

Kub made different transmission mainshaft versions during the product run - S/N will be important. Kub may even be willing to help with parts? Good luck, Dick B

 

[KFhunter]

I'm waiting on the WSM from messicks, the tractor will need to be split and transmission rebuilt, tempted to redo the clutch as well. It's working fine but I think it's 50% or less. Problem is I need this tractor soon for haying.

working on a splitting stand now. This will be my 2nd tractor split job so I'd like a good solid splitting stand to keep on hand.

 

[dfkrug]

Yeah, you should do the clutch, too. If it is a dual dry clutch, then it is certainly
tougher than a single. Realignment when reattaching was the hardest part for me.

As for the gears, shafts, bearings, and forks inside the tranny, I found the Kubota
docs to be excellent, and all parts available on a 15 yo B21.