Working on a 1978 955L 13X left side track adjuster. Track started losing tension during use. It would pump up to the correct tension, but would become slack immediately after any use. Started to repair as per instructions in factory Cat manual. Removed shields, broke track, unbolted yoke rod from adjuster. Next step is to slide front idler forward, but it seems frozen or pinned. Tried a pry bar, then a 1.5 ton come a long, then a choker around the idler and the other end rigged to a tooth on the bucket and roll the bucket to pull the idler forward; this all with the hydraulics maxed out. Nothing. I can pump grease in the adjuster fitting and get the idler assembly to move forward, but by no other method, and the yoke rod is free in its hold point on the adjuster. What am I missing? Anybody got any ideas?
The yoke is machined fit to the adjuster.... after the bolts have been removed it sometimes take a good whack with a maul to separate the two.
I'll check this again tomorrow, but I'm pretty sure I was able to see movement in the contact point of the yoke rod and adjuster. It may not be lose enough though. Thanks for the input!!
Look where the idler rides on the track frame clamp, theres some wear strips that keep it from moving up and down too much. Unbolt them and the idler will move forward.
OK, I'll check this tomorrow as well. I loosened four bolts on the outside of the idler clamp today and it didn't make any difference. I figured that taking the front idler apart was the next step, but I didn't want to do more work than I had to. I guess I'll just have to start taking stuff apart until it moves. I just wanted to make sure the wasn't some kind of hidden stop or pin that is stopping the show. I am assuming the idler and yoke is designed to just slide off the end of the track frame.
Look on the inside of the track frame. I can't remember exactly how it's put together, but you'll see the that it slides on the top rail of the channel. Look at the bottom picture in my previous post...that's the idler you're facing if you were standing in front of the machine.
Take a look at items 28 in the drawing. They're four heavy springs (encased in rubber from memory). They push down on the wear plates that bear on top of the track frame to take the up/down play out of the idler assembly. The four springs are tensioned by four bolts which push down on top of them. Loosen the bolts and the idler shoud slide free.
Looked at the loader a little today, but didn't get very far due to rain. I will post updates as they come about. Thanks
Since you are moving the idler past its normal running position something may be catching on a sharp edge. Like a worn/not worn spot. Releasing the spring pressure like Cmark mentioned sounds like a good thing to try.
Push the idler back a inch or so to relief pressure. Remove 1 or 2 of the shims #20 and you will have no more problems. Been there and done that!!
Sorry for the long delay on getting back to everyone about the track adjuster, but dad and I finally got back on it this weekend. He ended up getting the idler to slide off of the track frame by loosing the bolts that hold pressure on the vertical springs in the yoke. This helped, but it was still very tight and took a lot of pulling pressure with the bucket and a big pry bar until it finally gave up. After cleaning everything up and rebuilding the track adjuster, we noticed that one of the inner lower track frame idler slides was damaged. What had happened was a couple welds had broken holding on a wear strip allowing dirt to pack between it and the surface that it was welded to causing the strip to become a wedge and pinch the idler preventing it from sliding normally. We cut the welds loose, cleaned both sides and then reattaching. Installation of the idler assembly went smooth and after about 30 min of use the track remained tight. Hopefully that's that for a while!! Thanks for all the help!! Attached is a picture of the repaired wear strip. Hopefully it took.