I have an OC 4 and need to replace one of the track rollers closest to the drive sprocket. Please talk me through the process and offer any suggestions you can. If you could describe exactly how to do this I'd appreciate it. I hope to take all the directions and suggstions to do this correctly. I'm also looking for a roller assembly if anyone has a rebuilt one for sale. Thank You, Chris
Hi Chris -
My work has been on OC3's, but they have similar components. Not sure if there's a top idler or not.
I position the unit so the removable master pin is 2 - 3 teeth back (not half way down) on the drive sprocket. This provides a ready-made gripping assembly to help hold the track in position while removing the pin. If the teeth are worn to a point, secure (heavy wire, 1/4" chain) the pad just ahead of the link pin to the sprocket, to keep the front track section from sliding off the tapered teeth. Loosen off the track tensioner (spring assembly behind the front idler), remove the master pin retaining key (It's probably a 4" spike!) and drop the track. Sometimes the master pin is welded - if so, you'll have to back the tractor up so you can get at the inside to grind off the weld.
Move back to the original position, put in gear so the sprocket won't turn, and drive the pin in, fold the track down. It's a bit heavy.
Block under the top track so if it rolls or slips off the sprocket it won't smash something.
Jack the tractor up so there's clearance between the track chain and track frame to remove the roller, securely block under the transmission, unbolt the roller and remove.
I've wondered after having done this if it's possible to get enough track slack for roller removal by backing the tensioner all the way off and pushing the front idler fully back. Haven't tried that.
I never tried it, but I doubt there would be enough space to drop the roller by backing off the track adjuster. Just something to consider,,, if you have one bad roller, most likely you have more bad ones. Once you go to all that work to get one off you might as well figure on replacing the others. When you take the roller apart in most cases everything is shot. Also check your front idler for play in the shaft/bearings. In my experience once you start tearing these machines apart, you keep finding more & more things that need fixed.
Got it all apart like you said. Thank you for the instruction. And, like was mentioned I think I'll rebuild all while it's apart. 1 wheel is totally shot while the others have slight movement. Getting the wheels apart maybe interesting.
Axle removal: Once you pry the seals out, there's a heavy snap ring on each side of the bearing retaining castings. I remove the one on the side next the oil fitting, then turn the roller over, support it on 6 by 6 blocks, and use a heavy chunk of brass rod (actually mine was the differential gear axle from a 3-ton truck, about 1 1/2 by 6") between the axle and the sledge to drive the axle and lower bushing retainer out.
They come hard, and the brass prevents the sledge from brooming the end of the axle. And driving on the solid end of the axle prevents buggering up the thread holding the oil fitting.Then remove the second snap ring, and use the axle to drive out the second retainer.
Good luck!
Jack