Cat 953a under carriage rubbing questions?

[JD8875]

Moving the lower pivot forward before you bend/break an adjustment shaft is much easier. I was in the same boat last summer. Getting the bolts out of the master link is the hardest part of replacing the adjustment shaft. The bolts holding the pivot mounts to the track frame were no peach either. I suggest getting the torch bottles filled so you have plenty of heat. Then buy new bolts to put back along with a big can of anti seize. You will know immediately if the last guy anti seized the bolts or if he just threw them in the holes. I moved my pivot mounts forward using two ratchet boomers and short chains off the bucket teeth once they were unbolted, it went pretty smooth.

Good luck
John

 

[Scrub Puller]

Yair . . .

Getting the bolts out of the master link is the hardest part

The bolt together masters were just coming in as I was going out.

There were (I think) three types. One had a series of small "alligator" teeth, one (I think from Berco) had a single large tooth and there was another with two uneven sized teeth.

I thought they were micky mouse, the ducks guts or any other way you wanted to say marvellous . . . it beat the crap out of a jelly gun or flogging master pins in and out of eights and nines with a FBH.

I see on various machinery sites reference to issues getting bolts out which puzzles me as I recall no issues. There were no such things as impacts and all trackbolts were tightened with a couple of blokes swinging on eight feet of pipe.

Coming off was the same and I loved how you could heat the link cherry red in line with the bolt and they'd crack loose real easy and you could often back them out with a half inch ratchet.

For us trackies they were the best thing since sliced bread.

Cheers.

 

[Heavey Metal]

Hopefully the op will see the bad bearing when he breaks the track.

 

[Georgia Iron]

I managed to get the tractor back to our shop. Took my backup machine and picked up this one. 320 mile round trip of hauling loaders. Lost one 17.5 tire, and cracked another tire. Lucky I had one spare. Got 2 miles to the gallon.

I welded the track adjuster rod back together and that held all of about 10 feet. I ripped another ramp completely off my eager beaver trailer and turned a 1.5" steel bar into a pretzel and ripped all the hinges in half. Then of all things the ramp wedged in the tracks and tried to roll back around and jamb between the tractor body and grossers. Making it almost impossible to get off since the machine was still just barely balancing on the rear of the trailer.

But I got the 200 lb ramp loose and home we went.

The rock gaurds do indeed have another set of bolts to move the idler forward. Which is what the service manual tells you to do also. I have located the alligator master link and I will be in the process of breaking the tracks apart. Cat track adjuster rod cost is $300.00, cat classic aftermarket adjuster rod is $115.00. I am unsure of the quality difference. Any ideas if it matters?

I am unsure of the idler bearing as of yet. Will post repair pics as it occurs.

 

[Dickjr.]

Sounds like my luck. On my 943 which I have back running now , If I had moved the idler forward it wouldn't have lasted long. Maybe a couple hundred hours. My bushings were worn to the point they were flaking metal off. The pins have heavy wear as well. Yours may be in good enough condition moving the idler would get you a lot of time. I'm curious to the condition yours are actually in. Look at my thread and check out the pics of the bushings and segments.

 

[Georgia Iron]

I made it down to Cat today and was able to view both brand track adjuster rods. Cat brand and the cat classic part brand which is an "aftermarket part". Cats was $300.00. and the classic was $115.00. Can you tell which is what?

The seals were another $15.00.

 

[Georgia Iron]

I also did a little prying with my 10' pry bar. I lifted the broken adjuster up from the bottom. As it moves up the yoke moves away from the idler and the tracks tighten accordingly. It appears that the only reason the bar broke is because the idler bound up when it touched the yoke due to improperly over extending the adjuster bar too far vs not adjusting the rock gaurds/idler brackets forward to compensate for wear in the under carriage.

A friend I spoke to told me that once the wear exceeds adjustment, the rental company he used to work for has a second set of track adjuster rods that have been trimmed approximately 2"s in length. He stated they moved the under carriage adjusters back to start, then gas axe out one link in the track, saveing the alligator master link. Using the shorter adjuster they then run the under carriage to destruction.

 

[ship660]

Glad to see your on the way back to digging dirt. I have shortened some tracks on 953b&c models before. I would just cut out a pin and link. It is hard on the final drive segments it would also mess with the phasing of the rail. Instead of 40 links now 39 made more noise and occasional popping noises. The last one I did the guy ran it for another 1500 hours. Do the math at $100 an hour.

 

[Dickjr.]

I'm guessing the cat classic was the one with no paint on it. Got to save where you can. I have used cat classic with good luck on certain items. I'd use a cat classic for this in a heart beat. It seems to me that taking a link out could cause a whole other host of problems to come in the future. I would think it would be hard on the final drives. I guess if it had enough wear the pitch would agree with new segments because of the stretch. G I are you planning to short track your machine?

 

[old-iron-habit]

Cat Classic parts are made by manufacturing subcontractors and are not held to the same metallurgy as true Cat. Unless you are literally abusing the crap out of it,which I do not think is the case, the classic aduster will work fine. Good luck, Sounds like you are on the correct track. No pun intended.

 

[Master Link]

In post #3 look at the swing arm on the idler. You notice that it has gone past vertical toward the end of the roller frame. Anytime you see this there is internal wear on the pins and bushing in the track. Pumping your tracks out extends the rod out too far and there is not support for it so sometimes it breaks.

As far as taking a link out it has no effect on the final drive. The pitch on this chain is 6.91" and it should be 40 links long. The pitch is from the center of one pin to the center of the next pin. So making the chain 39 link long you still have the 6.91 pitch. However the pitch does start changing as internal wear increase. What happens then is your bushing start riding up on the teeth of your segments causing them to wear the tips thinner and then eventually breaking them off.

Taking a link out is the common thing to do for most smaller contractor as they can usually put off buying new chains for a while if money is tight.

Hope this info helps.

James

 

[ship660]

Thanks for the info James. I didn't know for sure about the pitch. I just knew they made a lot of noise and would pop on the segments from riding up on them. The rails where very worn on the ones I took a link out of. The guy I did it money wasn't the problem it was always time. I could take a link out in about 2 hours compared to changing the undercarriage. He would run them until time was available to change it out. All of the guys I work for seem to be in the time crunch mode more then money crunch.

 

[Georgia Iron]

I located the alligator link and broke the tracks. 1/2 drive sockets would not cut it. I needed a breaker bar with 3/4
Drive and a 15/16s socket to get the bolts out of the pads.

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Of course the bolt that holds the adjuster rod to the yoke broke off due to corrosion. This left some of the bolt in the yoke which held the pin in from coming out. I had to make a home made threaded puller to remove the side pins which held the yoke on. Then I was able to get it off and bore out the broken bolt to remove the pin.

I have not been able to get the rest of the broken shaft out of the bushings it rides in. Any tips?

 

[Cmark]

The broken shaft should have nothing holding it in. You may have to weld something to the end so you can get a grip of it.

 

[Dickjr.]

When I worked on my 43 , the shaft moved easily in and out. I wonder if you can get a big pair of vise grips on it and pull it out. Have you found your new adjuster rod yet?

 

[Georgia Iron]

When I worked on my 43 , the shaft moved easily in and out. I wonder if you can get a big pair of vise grips on it and pull it out. Have you found your new adjuster rod yet?

Yes I bought the cat classic aftermarket rod. The shaft that broke actually had some significant wear in the bar. It also appears the break took some time to occur. It is possible that it is bent a little in the bushing. For any one that is breaking a track for the first time, make sure that you stay clear of the track when you pry the alligator clamp apart. The track weighs enough to break your feet and legs when it flops towards the ground.

This is the first time I have split a track. I was surprised because my pins look really good. They have been turned but they look to have very little wear. Yeah, me. The guy that sold me the machine told me the under carriage was about 45% life I guess he was not giving me a sales pitch.

Second question. My next task is to rebuild all my lift cylinders. I bought a chain wrench at harbor freight but it is no where big enough to loosen the caps. What do you guys use.

 

[Dickjr.]

GI , I can recommend one thing for sure. Take the cylinders off and take them to a hydraulic shop. I tried to do this on my backhoe. The piston is so tight I couldn't pull the rods out of the cylinders. Those cylinders are heavy and the retaining nut torques upwards of 5000 ft lbs. It will cost some but its a convenience to drop em off and pick them up fixed. Those guys have the proper tables required to hold the cylinders while rebuilding. It can be done the way your doing it. I've heard people say they heat them cherry red to get them loose , I'd hate to do that to an expensive part. BTW to answer your question I used a BFP , big freakin pipe wrench.

 

[Georgia Iron]

Well, My track adjuster rod was one stuck sob. I ended up buying a 5 ton pull back ram and welded a big chain to the broken end. The bar was corroded and bent and crammed full of rust and dirt. Broke my weld twice and pulled a smaller chain apart. Ended up taking 2 7018 sticks to get the weld and big chain to hold.

This $50.00 ram payed for itself. Got it at harbor freight. If you have ever had a high bill from cat for this kind of work, I can understand why. Everything takes so much time.

 

[Dickjr.]

Looks like you will be up and running soon. I picked up my replacement final yesterday , dropped it off at the shop this morning. Your 19Z would not fit my 03Y , my tractor is a narrow gauge. We still might talk later on about it. Looks like your idler mount rock guard bolts came out ok as well. Post up some finished product pics.

 

[JD8875]

GI when you start back together remember to apply anti-seize to every bolt you touch. I was never a believer in it until I tore my 53 down for an adjuster rod. Anti-seized bolts back out, the rest of em twist off. If you don't do it for yourself do it for the next poor fella.

John