drive sproket alignment to roller frame on d69u

looks like possibly the sprocket rings were replaced at some point, it is possible that they weren't aligned properly during the welding process, also might want to check the outer bushings/bearings on the track frame, they help keep the track frame aligned, and they are usually worn out, this lets the track frame move to a toed out position which can cause the rollers to rub as well. they are about 8 inches in diameter and are under the big plate on the end of the dead axle and outer sprocket shaft bearing. Sprocket shaft bearings on the outer end of the dead axle could also be toasted which would let the sprocket move around and also potentially contact the rollers.

there are no adjustments on the inner track frame bushings, but if they were worn out they would also contribute to a toed-out or toed in condition for the track frame which could cause roller contact.

if he shimming is correct, (i don't recall any shims in mine, and don't have a parts book with me to look) then you could just as easy cut the sprocket ring off and weld it in the proper place. i did a sprocket ring swap between two sprockets as i had one with a bad sprocket and a good hub, and one with bad hub splines but a good sprocket. they were off the machine and i laid them on my big welding table and had a magnetic base dial indicator set up to make sure my ring was welded on straight and true and round. i just used 7018 rod to weld the rings on.

i can't remember if it was on here, or the ACME forum, but Mike Meyer and EDB replaced the sprocket rings on a RD6 and did a great job of documenting the process with write up and photo's. there are also some good conservation bulletins posted in the technical section for undercarriage repairs.

My brother in law used #12? machine screws with small washers and nuts to clamp the spoke and hold the proper alignment and welding gap when he welded sprocket rings in place on his D4D. It came out great.

Check that the axle is not bent. If the axle is bent toward the front the sprocket will be running closer near the roller.