Caterpillar 931 , 78U0438

Good evening everyone.

I bought a Cat 931 series 78U.

The right side does not steer.

The left side works.

I tried to remove the bulb as in the photo and everything seems ok.

The springs inside are also perfect.

When I press the right pedal the left track also stops, this is strange.

What could I check?

I attach some photos.

Thank you very much everyone.

I don't know anything about 931s but a common reason why older machines like 5U D2s behave like that is due to a broken component between the bevel gear and the sprocket on the side that unexpectedly stops driving, in your case your left track. It could be the bevel gear shaft, or the final drive shaft, for example.

Hi thanks.I have to say that pushing the pile of earth has a lot of force.The tracks rotate well and with force.Pressing the central brake stops everything.Pressing the right pedal also stops the left track.

I really don't know what to do or check.

I am guessing excessive slop in cross shaft bearings. Is it a pedal steer machine? Adjustment may make some improvements but to repair properly will require a lot of disassembly.

Hi.

I made a video .

If you can see it , you can see that the fork does not move at all.

Should it move ?

I don't understand how it should move.

Eventually to disassemble everything , do I have to remove those 6 bolts in the flange?

I don't even know how to get to the lower bolts.

Is there anything I can do without disassembling?

thanks .

Video link:

https://streamable.com/jqy6rh