450B track has no drive

[Chasman50]

I have a 450BC that all of the sudden the right track has no power to it. I split the track, removed the drive shaft, pinion shaft and clutch assy. I found no broken parts, pieces or anything else to suggest that there was something wrong. The steering clutch did stop the track to make a right hand turn, although when I let go of the lever and tried to make a left turn, there was no power to the right track. I looked in my service manual, and could find no reason there either for the problem I have. I took the steering clutch/brake apart & checked the disks & plates: no major wear or heat spots on them. Now looking at a parts blow-up, it could be the bearing housing for that side.

Any ideas?

Thanks!

Chas

[Lavoy]

Did you have enough freeplay on that side so the throwout bearing was not against the pressure plate fingers?
Possibly a broken spring in the pressure plate? Just a couple quick things I thought of.
Lavoy

[Chasman50]

Yup, I had the entire right side apart down to the ring gear. I only got as far as taking the cover off the left side to compare, and noticed a slight differance in wear between left & right. With the right clutch out of the machine, I reinstalled the pinion shaft and tried to turn it. It was solid. The throw-out brg is good, release springs & fingers have minimal wear along with the friction and steel plates. Linkage movement was normal. I can't imagine any water causing this effect. I hate to get a new pressure plate if the old one is still working properly.

I guess I'll put it all back together and get a total comparison then.

[Jack-the-Ripper]

I'm currently working on a similar problem. I found that the vertical shaft that twists the throwout bearing fork was contaminated by abrasive grit, mostly at its lower pivot. Combined with a broken return spring on the bottom of the same fork, this vertical clutch actuator rod was unable to return to a normal drive position after it had been actuated. If this were the case I would think you would have noticed it while removing the clutch/brake pack.

Ralph

[Chasman50]

Yeah, the system on our crawler is all moving. when the clutch brakes were replaced, all moving parts were reassembled with anti-sieze.

[Chasman50]

I put the machine all back together, and it worked fine for about 10 mins, then again no power to the right track. I took it back apart, and removed the pressure plate. I found that "Six States Distributors" in SLC, UT. can rebuild them for a decent price. I should have mine back, rebuilt by Thursday, 9-2-10.

Heck of a deal !