A track fell off my Cat 307. The idler arm seemed to be sticking out really far. It did not retract when left on bypass overnight so I put a block of wood on the ground and gently, slowly pushed the idler wheel in with the hoe. Got the track back on. No sweat and not my first time. Now the idler won't come out far enough to tighten the track. I've tried tapping on it. Raising and lowering and transfering weight to maybe loosen a possible bind in the slots the idler slides in. All while letting the grease pressure out and reapplying it. The wheel does retract via spring, now but won't come out far enough. Did I mess something up ?
If the track came off then the tension wasn’t there to begin with. Are you sure the adjust cylinder isn’t bottomed out on its stroke limit?
Pull the idler all the way out and check the recoil spring. Bob
Try to get a view of the bolt/rod and nut that holds the recoil spring plate (that the adjuster pushes) onto the idler. As the idler was 'out really far' you may have a broken bolt or the nut(s) has come off. When you forced it back together the bolt/rod might be jammed/catching and won't let the idler extend.
You can see the idler arm sticking out past the guides in that picture. Now, the face of the idler arm bracket won't come past the end of the guide on the frame. The other side, both side of the idler arm guides stick out past the frame about 7/16-1/2". I got it out of the woods and into my driveway and washed it and I don't see anything wrong with it. Not easy to see up in the track frame but I can see some nice shiny 2" diameter cylinder ! I'll fiddle w/ it some more before I take the track off again.... Thanks for the replies.
The spring in the red rectangle below is likely where you should be looking. That recoil mechanism is located in between the hydraulic tensioner cylinder and the idler. it wouldn't be surprising if you found it has come apart or even that the spring is broken.
Is the idler sloppy on the shaft? It looks cockeyed to me in the photo. Are the guides worn out?
Thanks for the picture, Nige. Hope the spring is OK cause even though I can find a new one for every other model Cat that's bigger, I can't find one for this. I got a better look up in there. The big shiny cylinder looks slightly misaligned with whatever it hits compared to the other side so I'll fool with that some. The idler wheel bearings/bushings seemed pretty good. The whole unit did not rattle around in the guides but I didn't reef on it all that hard. I do think that it is misaligned in the guides because one side comes out further than the other. And that's what I'll try to address today before I take the track off again.
I think it's over it. Whew. I let the grease out again overnight and pushed on it and wiggled it this morning. The guides are loose ! But measuring the spaces track>track , they aren't very different. So with the guides loose and no odd torque on the wheel, it pushed out to just about right. The track didn't fall off by it's self...there were some rocks and stumps involved. That round rock nearest was under the machine when it came untracked up above a little.
If that idler position in the photo above is with your tracks at the correct tension they it would appear that you are approaching the wear limit. If this machine only gets occasional use then removing a link from the track is an option.
Yes, Nige, I'd like to replace the tracks. They are a big loose mess. I'd like to try some rubber ones but can't decide on a brand. Only just starting that research.