Question about how tracks operate

I am working on a case 310 crawler. trying to remove the tracks. Am I correct in assuming the pin inside the bushing rotates/moves and the track pin is stationary in the rails. HOPEFULLY someone will understand what im trying so say. thanks norm

You are right in your assumption. The pins are stationary in the rails. I'm not familiar with case crawlers, but if you are breaking the tracks they may be like the older caterpillar's and have a master pin that has to be driven out. Done that many times. If this is the case and need a hint on the procedure give me a holler.

Honestly now days it depends on what kind of tracks your looking at. In most of the older dry, as well as the lubricated SALT tracks, the pin is fixed in the side rails of the female link, and the bushing is fixed in the side links of the male link. That being the case, the pin turns within the bushing in each type, with the major difference being one is lubricated, and the other not.

A few years ago CAT designed a new type of track that somehow allows the bushing to turn also. This is supposed to allow even wear around the bushing and prevent having to turn them like you had to do with the other two styles.

Now, if your asking how to get the tracks apart, here's that. With the SALT tracks there should be an alligator link. Basically it's a split link that has serrations to provide a lock between the two halves, and then uses the pad bolts to hold them together. With the dry type tracks, there is a master pin. The bushing in the link with the master pin is shorter than the bushings in all of the other links to allow the track to come apart. Usually the master pin will be identified by a dimple in one, or both ends. Too, if the tracks are old and somewhat loose, you'll often find it has a bead of weld around it to keep it in.

If it's welded, you've got to get rid of all of the weld first. If not welded, and still tight, then prepare to spend some quality time swinging a 10lb (or bigger) sledge hammer to get it out. What Dad and I always did was one of us held either a railroad spik hammer, or a custom made bar, against the pin. While one was holding, the other was swinging. This will get all bit the biggest and most stubborn pins out. Even with that said, you may still find you need to heat the link, or maybe even wind up having to cut the pin out. It's no fun either way, but it can be done with a little effort.

Good luck, and post back if you need any more info.

Thanks for the input. I bought a case 310 crawler last year and a parts crawler. Summer/winter project. I have always been able to take the tracks off without breaking them on some other crawlers I had but theres not enough room to do this on these. the one track has a pin with nuts on each end. I got it out with not to much trouble. when the nuts were tightend they were just about flush so it would seem there wasn't a lot of rust/dirt accumulated in them. 2 inch nuts. its a learning experience especially when you tell someone these don't have steering clutches to fool with as they basically work like a tractor. thanks to you all. have a nice day. norm in missouri

I think the rotating bushing is just a loose bushing over the regular bushing. That is the way it was on Cletracs built 80 years ago. Interesting that Cat went to Differential Steering and rotating bushings that Cletrac pioneered so long ago. Cletrac had a high track tractor, the Model F, back in the '20's. To give Cat their due, Holt built the "humpback" , an elevated sprocket tractor back in the teens I believe.

I've always been curious about the design of those model Cletracs, and have wondered what influenced how they were built with the elevated sprocket. Fast forward to the similar configuration that Cat went to, relatively easy to understand its less of a load on the dead axle, sprocket, and in short a lot easier to work on all around in comparison to the previous design, lot more detail to it, but its ironic to me, when you see these old crawlers with a design like that. I think the high clearance, small caterpillar tractors of the same era(post BEST/HOLT merger) also had the elevated sprockets. Maybe given the proven earlier design, oval tracks if you will, they spent a lot of time R&D and it took until the late 70's when it was finally released. Be good reading to learn how that evolved, what the problems were and how it came to prove out, before full production started.

Go to the link below from where you can download a file about undercarriage,it is IH based but applies to most tracks,it's free and easy to get,just go to the link,its a bit slow to load because it's in PDF format,once it loads you can download it by clicking on the floppy disk icon in the black menu bar at the bottom.
AJ
http://www.external_link.com/PDFs/undrcarguide.pdf

Go to the link below from where you can download a basic explanation of everything you need to know about undercarriage for the older tractors,it is IH based and its free,its a PDF file and needs time to load.
AJ
http://www.external_link.com/PDFs/undrcarguide.pdf

Below is a link to download all you will need to know about tracks for the older tractor,its in PDF format and need time to load.
AJ
http://www.external_link.com/PDFs/undrcarguide.pdf