Kubota KH66 travel motor stuck after one revolution

[John V]

Hey, I’ve got a confusing issue on my trackhoe. It’s a kubota kh70, uses the same sprocket and tracks as a kh90. The right track is able to rotate one revolution of the sprocket and then it locks up. I turn it backwards and it does one revolution then gets stuck. Forwards one rev and stuck. I guess it’s a gearbox issue??

 

[John V]

Also I don’t see how it’d be related but right before this happened I had a hose for the boom cylinder blow. I got that replaced and works fine. The left side tracks normally. Nothing sounds abnormal in the right side gearbox when it’s working, then it just locks up and you can hear the pressure relief valve.

 

[Coaldust]

I was going to ask if a hose had been replaced recently. I’ve seen lots of weird things happen after a hose replacement due to contamination inside the hose, created from cutting and crimping.

 

[John V]

Well after limping it out of the woods using the boom and the little bit of travel it had, it popped loose past the stuck spot. I’m able to run the track but there is definitely a weird noise coming from the gearbox when it turns past that one point. I think I’ll have to take it apart and have a look inside

 

[materthegreater]

Does that have a planetary gear set integral to the drive motor like most modern machines have, or is it the older style with the separate gear case?

 

[John V]

Separate gear case, looks like this

 

[materthegreater]

Oh yes, similar to the old KH28L that I had. It may actually be easier working on that than a modern final drive. It may be difficult to find a new gear though, if that should be your problem.

 

[John V]

Somehow this bolt head broke off, which must have been what was jamming everything up. Probably busted some of the gear teeth when it finally broke loose.