I have an older 977H 53A. It looks like I will have to replace and repair the tracks. What tracks interchange with it . I can't read the link numbers. But the master link is readable. It is 2S1750. It has been hitting the link pin retainers on the carrier roller flanges. This seems to have been going on for a long time from the wear marks. But now it is getting excessive on the left side. The roller right in front of the sprocket on the right side is bouncing around without bearings. I haven't lifted the machine to see what is up with the rest of the rollers. Though at least some are still rolling smoothly. Wild question, has anyone ever converted a machine like this to rubber tracks. I don't have any rocks and it would be awful handy to be able to cross the road or run down to the neighbors to dig a little. Not to mention dominating the 4th of July parade. robertbible at gmail dot com robert
This is the site I look to for track interchanges: http://dracoequipment.com/Parts Links and Pages/All_Cat_107A.pdf As for their list, D7, D7C, 977 E,H,K If the link ears are hitting the rollers, first look to the dimensions for the links, then look at your rollers, most likely they are worn so far the flange is extended and hitting the rail ears. Time for rollers or a trim if not already done and rails, 37 link 8.0 pitch. If the pads have no grousers left then you will need shoes too.
that is kind of what I was figuring. I did not know that you can trim the flanges. What I am worried about is that it doesn't have the 977 track. The tractor has been around and at some point someone was pretty free in using whatever fit. I sure don't measure 8" pitch. I will go back with mics and check again. I will also recount my pads. I was hoping to pick up a set with some life still left in it. I noticed that the 977L and some other D7 have 8.5 pitch... thanks for the reply...
A 53A was originally intended to run on 8" pitch track links. However 2S-1750 is a standard LH link (not master link) for an 8.5" pitch track group orignally fitted to a D7F of 93N/94N prefix. As far as I can see there are 2 heights of link - 4.93" (Std.) and 5.23" (extended life). Do the bushes on your tracks appear to be running correctly on the sprocket teeth, or is there so much wear you can't tell..? For the carrier rollers there are 2 different Part Numbers available depending on what height of link you're using. This may be your problem.
To get your track pitch, measure from pin to pin across 4 links. There is also a chart to tell when you are at maximum wear to links. Wear Limits - Pins and Bushings Do not consider for lubricated chains 4 sections of the link assembly To determ ine the average internal pin w ear m easure across a piece of chain com posing of 4 links (5 pins). The track section, w hich m ust not include the m aster pin, should be on the upper side of the track and w ell stretched. 75% w ear is recom m endation for pin and bush turn (noted in green) Caterpillar | International | Allis - Chalmers | Fiat | Landini - ** | Case | John Deere | Komatsu Machine Model New Percent Worn Chart 25% 50% 75% 100% mm in mm in mm in mm in mm in Caterpillar 935,D2,933C,D3,931 622 24.48 625 24.6 628 24.71 632 24.87 637 25.07 D4,933E,G,955c,941,943 686 27.00 689.5 27.14 693.5 27.31 698 27.48 703 27.67 D6,951,955C,561 686 27.00 690 27.17 694.5 27.34 699 27.51 704 27.71 D5,955K,561C,951C,953 702 27.64 706 27.79 710.5 27.96 716 28.18 722 28.42 D6C,D7,572,977,D8,583,955L, 963 813 32.00 817.5 32.18 822.5 32.37 828 32.59 835 32.87 D7E,F,571,572E,F,977L,973 864 34.01 868.5 34.18 874 34.4 880 34.64 887 34.92 D8H,583H,983 915 36.01 920 36.21 925.5 36.43 932 36.68 939 36.96 D9Super,D9D,E,G,594 1042 41.03 1046.5 41.20 1053 41.45 1060 41.73 1070 42.14
Chart did not copy as well as expected, drop down to the 963, just below is the wear numbers in mm first then inches with 813 and 32 being new dimension or 100%. 32.87 or just under 33 inches is full worn out for 8.0 pitch, for the 8.5 pitch the next line with almost 35 inches totally shot.
Not all rollers can be trimmed, if they were trimmed once then they won't necessarily take another, need to find a decent used or fairly new or even a new one to get measurements of the diameter of the rolling surfaces, yours may just be due to change, especially if bearings are done. At the outer edge of the rollers look for cutting torch marks, that would be a tattle as to trimmed before.
I finally got back to this... If I measure 10 links, I get 87 inches. From the chart that appears almost worn out for 8.5 pitch.. e.g. 0.4 x 87=34.8.. I count 38 links. This tractor has an Oregon forestry heritage and they were pretty cavalier about swapping parts; if they fit or could be made to fit... I suspect that the sprockets and tracks were changed at some point?? If someone has a line on 8.5" pitch tracks and idlers that are use-able please drop me a line at robertbible at gmail.com
You might check with your local Cat Parts and Service Rep. Those guys usually know what is going on in their areas, and will know if there is a set of "farmer" undercarriage laying around. This is hardware removed from a daily use machine that has enough wear left to last a farmer or occasional user for years. Regards, Clark
Okay, It is 13 years later, and I haven't done anything on the tracks. I am retired now and we have a bigger place and I either need to fix them or get another machine. I have looked at a couple of 977Ls but have not been impressed.(trading one problem for another) Okay summary: 977H 53A Tracks are 8.5 pitch with 2S1750 indicating D7F The drive sprocket also measures 8.5 but is not segmented. The track rails are labeled 977H. The bottom roller has a casting number CAT8S3111 ( which I can not find any reference to) I am thinking of buying a new set of chains for a D7 I am not sure what rollers to order . Will the D7 rollers fit the 977H track frames Similar problem with the Idler. The Drive sprockets look okay. But, one side final drive is seeping!! This is a major investment in an old machine. But I have been maintaining and fixing the other things and it is pretty good machine. Especially when I start looking at what is available. It has effectively been a low hour ranch machine for 50 years. I am open for advice as to what to order and who to get it from. And any other 2 cents. thanks robert
You need new sprockets with new or even decent rails. See what sprockets are available. The problem with a 977 is cost. It is not cheap to do undercarriage on a 977 as in easily over $20K if you need rollers. Probably more than the machine is worth.
I'm afraid you will have to be more sppecific. There are five groups of 53A-prefix machines when it comes to parts. I don't know how undercarriage fits into that equation but if you are asking "what fits" then please supply a bit more information. The groups are: -1-1906, 1907-2999, 3000-4796, and 4797-8886, and finally 8887-Up. Don't need the exact S/N, just need to know which group your machine falls into. Can you see any numbers on the sprockets.? How about posting some photos of them.? In fact post some photos of the ilders, track & carrier rollers as well as the sprockets. Not a good Part Number I'm afraid. Again a photo could help with identification.
The D7F 8.5" pitch track groups have a total of 38 links including the master link. How many links do you have on your (assumed derived from D7) current tracks.? FYI 977 tracks are also listed as 8.5" pitch.
The d7-17a and 977H-53A track are 8 inch pitch and D6C track do not fit on and D7E track are 8 1\2 inchs like 977K
38 tracks 8.5 pitch. I don't see why I will need new sprockets. These appear in good condition compared to ones I see at auction.. The track frames are labeled "977H' The serial number is 53a2187 Engine number I use is 76A346 I have been looking at newer machines to avoid the investment in this older one. The problem is even an 80s 977L which is 20 years newer is going to have a lot more hours. The history on this machine is it was a logging tractor that was scrapped. An industrious operation took multiple of these machines and pieced together working 'Ranch' tractors. The Logging grapple was removed and replaced with a large bucket (probably not originally 977). The engine is from a D6 and the tracks are from a D7. The rear winch was removed and a Drott rear ripper tool bar was added to use the the third hydraulic function originally used for the log grapple My friends Dad bought it for his ranch in Oregon. They moved it down here to San Diego to build a house. I figure for the 30 years they owned it sat off and on for at least 15 years. I have had it for 30 years I have maybe 1000 hours on it. The pins are relatively tight. The hydraulics are strong and mostly new hoses and relatively leak free. The engine runs like a dream. The cooling system is all new. The turbo and injection pump were rebuilt when I got it. If someone would rebuild the undercarriage for me for $20K I would probably jump on it. My wife is convinced that if I decide to do the tracks, We will have a cat on blocks without tracks until I die.
So if that is the case how did someone manage to install 8.5"-pitch track links on a machine that supposedly takes 8" pitch without changing the sprockets.? Maybe they did change them. That’s why in order to help you we need to see some photos.
Worn sprockets on new rails will wear out the new rails much faster as will new sprockets on worn rails. They are designed to work as a matched set.
Yes they did something on the sprockets .. the track chain link is clearly 2S1750 which is 8.5,,, and everything measures that way
Yes they did something on the sprockets .. the track chain link is clearly 2S1750 which is 8.5,,, and everything measeures that way
Yes they did something on the sprockets .. the track chain link is clearly 2S1750 which is 8.5,,, and everything measures that way
picture
Is there a trick to uploading pictures. I tried attaching and dragging.. both with "oops there is a problem" I resized to a smaller pic with same results. I tried it in chrome and firefox with the same result.. thanks
Click on the "attach files" paperclip located on the bottom LH corner of the box where you type your replies. Select the file you want and upload it. Works with jpg & pdf files, may also work with other file types.
There seems to be some creative workers out there. I did not chase it down, or find out why, or even if for shure a salvaged 977K had what seemed to be 8.5" links. (I think this has been done before). I would not ever drop 20k on it. Then again the sentimentality of the machine may cause a person to try very hard to work it out. Posting pictures is a good step.