Got a few leaking bottom rollers on the old 941 that I want to rebuild if it is feasible...…….good idea to try? I will definitely not buy new cat rollers for a machine that hardly gets used, but would like to try the rebuild option on one or two to start with to see how it works. There are about 5 to do in total. Are they likely to need both bushings & seals? I just wanted to try to be somewhat prepared before yanking out a roller...….. I have a parts book, but never having seen a roller apart before, it all looks greek to me...……...
you can get replacement shells with bushes already installed. Offroad Equipment would probably be a good point to start. www.offroadeq.com/ You may need to replace Duo-Cone seals at the same time, or the Toric rings if the metal parts are still good. This guy re-shelled the rollers on a 955 and the story is told (amongst other issues) here ........ HeavyEquipmentForums
Ok, thanks. We ordered both the Duo-Cone seals, the Toric rings & a retainer clip, enough to do one roller & go from there after we see if it is successful. The shells look ok, externally at least, so if the bushings are still good we will leave them to be reused. BTW are the cap bolts that hold the rollers on coarse or fine thread? I wonder how they will come off? Note on the one pic, the one bolt is broken off. I did spend some time yesterday reviewing the 955 roller rebuilding that you had mentioned from a couple of years ago. It was helpful.
A couple of thoughts. A complete Duo-Cone Seal assembly includes two silicone rubber Toric Rings. You don't have to buy them separately unless you plan on just replacing them rather than the complete D-C assembly. The bolts that secure the end caps are 3/8" coarse thread I think. Post your Serial Number and I'll sort some parts listings out for both double & single flanged rollers. These will work so long as you don't have aftermarket rollers installed (look for the Cat logo cast into the end caps).
Ser # is 80H2988 on the 941. The seal kit ordered is both the Duo-Cone seals & the Toric Rings, if we understood it correctly. The part # for what we ordered is # 9W5224 which we understand to be the whole group. Hope we have that right. I was referring to the bolts that secure the rollers to the track frame (4 bolts) & wondered if they were coarse of fine. I believe they will be 3/4" diam.
The Duo-Cone Seal Group for your track rollers is listed as a 2M-2858 which upgrades to 9W-5224, so it appears that you have the correct P/N. Attached the parts listings for both single and double-flanged rollers. The bolts that secure the rollers to the track frame are actually 5/8" coarse thread. Do you have access to the necessary 224-9466 tool to install the Duo-Conde seals..?
No, we were going to try it without. Can we do it without one if we are careful? Do you remember if the 955 man that rebuilt his rollers used the tool or not? I could always look back in the post to see if he mentions it. Thanks for the helpful pdf files as well!
You can do it without, it's just that the tool makes it a lot easier. On a really big seal it would be pretty much impossible without the correct tool. It helps to understand how the seal works, and why everything must be 100% oil-free for the installation. In the diagram below the Toric ring #2 is jammed between the ramp #7 and the corresponding ramp in the housing (not shown). When the ring #1 is pressed down the Toric Ring rotates in an anti-clockwise direction and becomes "the spring". If the Toric Ring is allowed to slide on one or both of the ramps it will not function as a spring and the seal will most probably leak. The #1 mistake that is made installing Duo-Cone seals is that it's a pretty tight fit to force the Toric Ring past the Lip #8 on both sides. The first thing that folks do is to grab some lubricant to help the process, but if you want the seal to work right after installation that's the last thing anyone should be doing.
I have done it with out the tool. It is alot easier with it though. But can be done without. Be very careful as all of the corners are very sharp on the steel rings. You can end up with many cuts just like a paper cut in a heartbeat.
10-4 on the cut hands I never had the luxury of a seal tool I always use a blunt screw driver but do not roll the o ring in you have to push it in as you hold pressure on the metal seal and yes always install dry and make sure the part where the o ring goes is cleaned up good
It was a long time ago but don't the rollers have to be put in a press to separate them? I remember in school I went for work experience at a heavy equipment repair shop and spent a day pressing rollers apart with a horizontal press designed for it. I'd guess it was a 75 ton or larger press. When pressing they would start going tick, tick, tick and then a big bang when they finally came loose. You could see the pressure build on the gauge. I think you had to turn one of the mounting flanges 90 deg's in order for them to come apart. I think it was so the shells could be rebuilt on automatic equipment or just new shells installed. The shop had 2 idler rebuilding machines that used to run 24/7 back in the day. I also remember having to cut a hole in the side plate on hollow idlers so the heat from welding wouldn't build pressure inside. After they were built up, you'd weld the circle back in. It was easy to tell if the idlers were ever rebuilt because they'd show the patch welded back on. http://www.maruma.jp/pdt_r_ip.html
Got one roller off the machine & got the two retaining rings off & one collar off, but the other one is giving trouble......seems seized to the shaft. Any tricks to getting it off? We positioned in in a press just to hold it steady for us to work on. On the one end that we were able to get apart, it looks like the duo-Cone seals may be good, but will have a better idea once they are cleaned up. Just doing one roller at a time to see how it goes, as winter is setting in here & don't want to have too much apart at one time.
Does this help at all..? Probably a lot of penetrating oil (and a fair amount of patience while it soaks in) required...... HeavyEquipmentForums
Good idea! I guess I missed that when I read that guys post from the other night, but that makes sense for sure. I do have a heavy vise too! Stay tuned...……….
No use re-inventing the wheel. I'm sure the end caps are well rusted in place. The two P's spring to mind - Penetrating oil & Patience.
Success!! The vise, penetrating oil, two adjustable & a few taps on the one side with a 2lb hammer & it got things moving. Thanks for the tip!
Ok.....now I get it, once it is apart & cleaned up. The rubber ring needs to twist up the ramp in order to hold tension against the metal mating Duo-Cone seals, thus the need to be dry. If they were lubed they would slide & not have the intended effect. BTW the old Duo-Cone seals on the first roller taken apart are about 1/2 the thickness of the new ones but they look good...…...reuse them, only changing the Toric Rings & keep the new ones for the next roller if it is worn worse?
How does the width measurement of the wear surface of a new seal compare with the one you removed..? That's the shiny bit in your photo above.
Mating surface width on the new one as shown in your sketch is approx. 1/8" & old one is about double that at 1/4".
How wide is the face in total on your seals..? Is the wear surface still pretty smooth or is is grooved from dirt getting into it..?
Old one is .627" & the new one is .652".
It sounds like the old one should be good to use again. The condition of the surface (as in how badly grooved it is) would probably be the clincher to re-use or replace. Any chance of a close-up photo..?
Here is one set of the old seals. I looked at them with our mechanic & we think they are worth salvaging the seals & just change the Toric rings. If it doesn't seal well we will start changing the seals along with the rings.
Hard to tell from a photo but they don't look too bad. Try reinstalling that one with new Toric Rings in it and see how it goes would be my thoughts. The perceived wisdom regarding Duo-Cone seals is that once you disassemble a working one you should really replace it. The theory being that you'll never get the two metal faces back in exactly the same alignment as they were previously. If there are any significant scratches or grooves in the faces caused by dirt getting into the seal that makes it even worse. However I can recall quite a few that I've seen pulled apart and put back together again without even replacing the Toric Rings and they worked fine afterwards. I think you ought to be OK.
Have been off this for a while & just getting back into it. Pulling the caps off to better reach in & clean the inner ramps for the Toric rings. One roller at a time, as the winter weather is moving in & don't want to have too much apart at one time, as the machine is outside. Going to use all new bolts that hold the caps in place...….
That one looks to have cleaned up pretty well.
The other bushing assembly came out with more difficulty, so we had to use the press on it. What is the best way to clean up the ramps that the Toric rings ride up on, on the roller shell itself? They are fairly rough. We took the bushings out to get better access for cleaning. Put the pin back in to shove the bushing assembly out.
They need to be pretty rough in order to grip the Toric ring and allow it to roll and perform as a spring like it’s supposed to. A good spray with any cleaner that doesn’t leave an oily residue on the ramp should do the trick.
I used to use a small wire wheel in a grinder to get as much of the dirt and rust out as possible. There will be some pitting but the new ring will almost always fill the spaces when reinstalled and pressed tight from the opposing seal half.
This is bringing back some memories!
Finally had some warmer weather today, so back on re-assembling that roller that was started on in Dec. Outside work so have to pick our days! Just have to put oil in it & reinstall it, then on to the next one.... That will have wait a while though as it's still winter here & the install happens outside...……...
Finally getting back on the track roller project again. Cant believe it was Feb when last working on this......nice weather now so time to resume the project. For the oil in the track rollers, would the TO-4 # 30 be the correct oil to use today, or is it better to stick with the old standard #30? Have the To-4 in stock...…..
Got the LH side bottom roller installed & oil in it. Got going on the RH side where there are at least two that leak & need rebuilding. Had to split the track in the RH side as I took a link out a couple of years ago & couldn't get enough slack to get the rollers out. Cut a mouse hole in the track frame where two of the bolts broke off too high up to get ahold of them. Burned out the slugs from the top carefully, then ran a tap through....threads are good. Now onto roller #2 rebuild...……..have it apart now & ready to clean up.
I haven't rebuilt a roller in 20 years. When I could buy them for under 200 bucks I quit beating on them.
Time consumers, hard to justify unless absolutely have to rebuild your own.
Well, the Cat rollers are over $600 CDN & I did get a couple of Berco to act as spares while rebuilding the cat ones & wouldn't you know it, they are not a fit, not even close. We can buy a seal set for the Cat from Cat for around $120/set, so at this point we will keep on with the rebuilds, one at a time as time permits. I must admit, it is hard work though!!
Put the 2nd roller on & filled it with oil & now it's onto the 3rd one. Just two to go now!
I checked my supplier just for the hell of it. The Single flange roller assembly was $182.00 each, the double flange was $197.00 each. KDS brand I believe.
When checking costs on the single & double flange bottom rollers I asked for the Cat Classic option to keep the cost down & they only offered OEM only. Looks like $555.68 for the one style & $686.43 for the other...…..ouch, that's why I decide to rebuild.
I wouldn't put classic parts on my push mower now days. The quality has been crap for awhile.
Rebuilt 2 more bottom rollers today. We are starting to get good at it now!
Nice job. Are you saving up for some replacement track shoes already..? I hope so.
No tack shoes on the horizon for me......this old machine is just a hobby machine on our " little farm" here & gets used very little. The old shoes will serve me ok for the little bit that I use it. I am just glad that leaking rollers are fixed for now!
Shoe retainer bolts get much thinner won't have to worry of taking them off, they will self eject!!
You are right about that...….those bolt heads are getting mighty thin!! Luckily I have a 20 or so new ones waiting to take their place, should they start popping off!! After buying the loader I ran some weld beads to "thicken" the grousers bars at key points & there is still lots left, so I should be ok for a few years at least!
There is the ole beast, raring to go again!
Almost strikes me as to either Wrong shoes, wrong rails for shoes or rails so worn Pin to Bushing as to be shot with the gap so wide. My old AC is worn slick where even then the shoes still overlap when flat.
I think you're right about the shoes being either wrong for the rails or just badly worn DM. That was the reason I made the comment in the first place. There doesn't seem too much in the way of internal pin/bush wear that I can spot. Look at the wide range of variation in the gaps between adjacent shoes. Even more pronounced in the same photo over the back of the sprocket.
I think the shoes are just "very worn" & hence the gaps between shoes. A couple of years ago I took one link out of each side when the track adjusters were rebuilt, so the links had stretched considerable, but I think this is a case of extreme shoe wear. The lead & back edges of the shoes are almost razor sharp!! I predict I can still get 200 hrs out of the shoes & that equals 8 years time for me!!
I did notice they do still have lead and trail edges just separated a LOT, has to be incorrect shoes. Mine at .160 and excessive pin to bushing wear.