Kubota KH90 track problem

[Treefeller]

I have a 3.5ton Kubota kh90 with the old track off and the tensioning ram compressed as far as possible, had to use a ten ton jack, but cannot get the new track on by about 50mm. The track size is 300x109x41 . The old track was 300x52.5x84. Counting the lugs on the tracks gives 41 for the new and 42 for the old though I cannot see that one lug would make such a difference. I have removed the idle wheel and cleaned out but cannot remove the ram as it appears to be stuck/ rusted in place. Struggling with this so any advice appreciated. Thanks.

[Muz]

On an old machine like that they would usually have 2- 3 inches of free travel but it sounds like yours is too short. You are comparing a longer track well worn with a shorter new one with no wear ! The best you can do is remove the idler assembly and tensioner wheel from the frame and clean out all the dirt to make sure your ram is fully retracted and there is no dirt obstructing the position of the tensioning unit from seating fully home, your other option is to cut a link off your old track, that will work for a while , but the pitch will be so far out your sprocket will wear like buggery , but thats how the old boys did it

[Treefeller]

Track problem.

Many thanks for your reply. I have already done as you have suggested in removing the idler and clearing out all the dirt and crud and was then hoping to be able to remove the tensioning ram to check it but it is immovable . Looks like it’s rusted in place , I cannot see any bolts holding it in place and assumed that it would be free floating. I haven’t been able to source a workshop manual to see how the ram might be held in place. I have been spraying diesel around the ram via the greasing plate to see if this will loosen any rust but this has not been successful so far. The old track is unusable as it is broken in two places with delamination of the rubber. Do you think that the ram will be free floating ? Cheers kirk

[Muz]

Ah .. I assumed with a machine of that age the track was steel .. so you cant cut anything off it .. the tensioning unit should be a self contained piston with a base plate which was usually quite thick . Ive never had one out of a machine that old, but certainly the later KH machines were self contained units, you could get something through the side hole and under the the base to lever it out.

[Treefeller]

Track problem

Thanks for that, I will continue with attempting to get the ram out.

[Treefeller]

Track fitted

As an update to my problem. The tensioning ram piston would not retract fully (the ram was seized or rusted in place) I removed the idler wheel assembly and continued pumping grease into the ram until the piston came out. On examination it was clearly badly rusted where it sits outside the ram. I cleaned the rust and was able to get a polished finish and replaced the piston then with the grease nipple removed I was able to push the piston right home. It was still a tight fit to get the track over the idler wheel but I managed with the aid of a ratchet strap. Thanks to all for any help.

[Muz]

As an update to my problem. The tensioning ram piston would not retract fully (the ram was seized or rusted in place) I removed the idler wheel assembly and continued pumping grease into the ram until the piston came out. On examination it was clearly badly rusted where it sits outside the ram. I cleaned the rust and was able to get a polished finish and replaced the piston then with the grease nipple removed I was able to push the piston right home. It was still a tight fit to get the track over the idler wheel but I managed with the aid of a ratchet strap. Thanks to all for any help.

Good job. The real fix is to replace it with a proper chromed rod or similar as the rust will just bubble up again, you can get them made quite easily to spec from a good machine shop