I bought my first tracked machine, a CAT 955L loader, about 1 1/2 years ago and it's just been sitting unused and I don't have a feel for it yet. Last weekend I decided to take it for about an hour ride around my property on some old logging roads. Everything felt good on the machine but when I came to some rocky sections I thought the undercarriage was self destructing with all of the horrible noises it was making. It was like the final drives were skipping gears or the track bushings were skipping on the sprocket because the whole machine would jump along with popping noises. I know there wasn't any skipping taking place because a few times I was going slightly downhill and I did a test by placing it in neutral and letting the machine coast but the terrible noises and jumping were the same. The only thing I can think of is some sort of interaction with the rails and the bottom rollers but I don't know if there is a problem or do all tracked machines not like going over rocks? After I passed the rocks everything got nice and smooth again. I think the (SALT) undercarriage is in fair shape but I did notice that one track got very loose so I think I have a blown adjuster or broken spring but the tight track was making noises and jumping just like the loose one.
Basic answer broken parts. When I get into rocky stuff I just slow waaaay down and pay close attention to what is infront (going under) of me. Do you have rock guards on the machine?
Yair . . . OldandWorn. Hard to say from your description but if every thing went smooth when you got off the rocks chances are that every thing is fine. Running over rocks with a track machine is always rough and you need to idle down or decel. Cheers.
Thanks for the replies! Well, I was going slow as possible in first gear. Any less throttle and the machine would stop moving. Maddog, no rock guards but there is a guard on the lower part of the sprockets. These rocks are mostly large flat ones but they are almost completely buried with maybe just 1 to 3 inches sticking out of the ground. I would say that you could easily drive any automobile over them without damage if going slow enough. The same sort of popping noise and jerking happened even before I got into the rocks on a relatively flat road that is paved with shale. I crossed a small erosion channel about 1 foot wide and 6 inches deep. The machine made such a ruckus that I got off and expected to see something damaged on the under carriage. Maybe this has something to do with unlevel ground rather than rocks?
Could be some sticking bushings if the machine's been sat for 18 months, even though the tracks are SALT.
OldandWorn Please don't take offense at this, but could it be because you don't have any experience with the machine except in good dirt? Any time you put tracks on rock they make some ruckus, even when in perfect condition. Flat rocks are bad, as the grousers land on them, and make it rough, and even slightly burried rocks can make a rough ride. That said, it is always better to go easy and ask questions if it is doing things you are not used to. Nige mentions stuck bushings. If so, the tracks will take a "set" and will look lumpy instead of being smooth. This will make the problem of rocks worse, but will also make a rough ride even on good dirt. As this is an old machine, even though it has SALT tracks, the L might be missing. That would be the Lubrication that keeps the wear and noise level down. I have seen it many times when you get dry links and the track starts to stretch out due to internal wear. You mention one loose track. It could be the adjuster, or it could be a stretched track. Measure the distance from the fixed part of the track frame to the idler on each side. If they are the same on each side, yet one track is loose, it is likely stretched. Since I read that it is making lots of noise on you crossing a small ditch as well, I think it is mainly internal wear and dry links. You can run it until a pin breaks, then put a new pin in and go some more. I moved a large excavator recently, and with only half a track on the trailer and half off, the links and pads twisted about 15 degrees from level. It is pretty worn, and has broken pins several times. I just put a new pin in and run it some more until I am able to replace the whole link assembly. Without knowing how stretched they are, it is hard to say how long it will last, but keeping it on good level ground will help it. Good luck
No offence taken Jerry as this is the reason for my post. First time on bad ground and I’m trying to determine if I have a problem or not. The popping and jerking especially on that small erosion rut just doesn’t seem normal to me and I wasn’t exaggerating on how bad it was. I think the best thing at this point is to have someone drive the machine while I take a look at the tracks to see what is making all of the noise. I suppose I could have dry links but there is definitely no bunching or strange noises. Actually, I’m very surprised at how easily this machine will coast on its own if the ground is anything but flat. One of these days I want to try to inject or check the lube in the pins if that is even possible? I have never seen any oil in this area so they could either be lubed properly or dry, I just don’t know. I have a feeling that the seller knew there was a track adjustment problem because he mentioned that he likes to run the tracks loose when I asked about the sag but it just went in one ear and out the other at the time. When I got the machine home I adjusted the tracks and one stays tight but the right side drastically loosens back up after a few hundred feet of tracking. I think I adjusted it a second time but it keeps getting loose.
As Jerry said. Measure from the idler to a fixed point and see if the idler is retracting or the tracks are just stretching. Then you know what you need to deal with.
I did that when I first adjusted the tracks and I also put a mark on the frame. The idler keeps retracting.
Sound like the seals in the slack adjuster have taken a crap. Once you pump up the tracks do you see grease coming out around the back of the adjuster? Either there or where the zirk fitting is.
I haven't seen any grease leaking inside the little door that you open to access the zerk. I will need to take all of the shields off to get a better view of the spring and adjuster. Even after looking at the manual I'm still not sure where the seal is located or where the grease might be leaking from.
The seals are inside the cylinder your pumping the grease into. Sometimes the end is farther back and there is all kinds of dirt blocking you view. If you take off the shield I'm pretty sure you'll find a bid blob of grease. We had this happen a while back and your going to have to break the track down to remove the yoke that is mounted to the front idialer. If you plan to do this your self make doubly sure the crome on the shaft is in good shape. Ours was pitted bad from all that dirt packed around it.
OK, thanks for the info!
had to cut through a small bluff for part of my road. there was about 3-4 ft exposed in the road before i finished filling and my old d-75 loader felt awful when i ran over it. that is when i understood the space shuttle road being unpaved because hard pavement beat out the bearings on the carrier. i would say what u felt is normal.
To help inspect the track on my JD 450G dozer, I push both the blade and the rippers down and elevate the machine and cause the tracks to run while I carefully walk around and study them....the exact details of this procedure withheld as one could presume I have an operator helper .... point being this allows one to see what is happening. * If you look in your manual you can find the specifications and probably a procedure to measure/inspect the track to determine the new specs vs your condition. For example, knowing the links (I think these are the "rails") are worn and scalloped can help direct you to determine what is likely going on. Let us know if you cleaned out the packed dirt around the rod....and what you found out from your inspection. And what type of grousers? ** As to the operation, use care in making your operating motions when the tracks are not fully loaded uniformly (like on smooth flat dirt) as the machine will be 'jumpy' and more sensitive since the track friction typically dampens the response; when the track is on a point or bump near the CG of the machine it will respond more rapidly, of course this usually occurs when you are driving near your service truck or pickup truck since you wanted to be close to your tools and fuel etc, or a fence/gate post or a water line hose bib.....then ouch or close call occurs.
I think most 955's had triple bar grousers. I cann't remember for sure but I think on our 555g to check track tension you were to lay a bord from the front roller to the idelear and measure with a tape at the lowest point. I think it was 2-3 inches of sag.
I didn’t take my machine back out for a drive but I took a close look at the track rollers and I noticed that 3 are double flange and 3 are single flange. I think the jerking and popping noise might be the rails trying to go back into the double flange groove but they are hitting the smaller inside flanges of the roller first. From JDOFMEMI’s description of pads overhanging a trailer I can see this severe twisting happening on rocks or unlevel ground. The machine tipped a few times on the rocks so I know the entire weight on the machine was resting on a very small area. Bob and buckfever I believe I have double grousers and they have had bars welded on them at some point.
Well I'll be darned. I've seen a few 955's and they all had triples on them. But I guess you could put on any pads you would want.
Hang on tight!