Cat 951-C in my sights

[kshansen]

Spent quite q few hours removing broken bolts.

Drilling, heating, welding on washers and nuts.]

Like Bill Scranton the welder who retired a few years back from the quarry I just retired from told me once when I was fighting some broken bolts in a crusher bowl, "Just remember, You just have to be smarter than the broken bolt!" Well that and more stubborn! Have a feeling you are more of the first and a bit of the latter one!:notworthy

 

[Nitelite]

Just keep on keepin on!

I have the roller frame laying on its side in the shop. The three 5/8" bolts are the ones located under the tractor that attach the roller frame to the loader frame. The first thing that I did was to grind the broken bolts level with the surface as shown.



Next, I drill through the bolt and out the other end. At this point I don't know what method I will use to remove the bolt but once drilled, I can not loose center of the bolt later on.


Next I drill twice more with successive bigger bits. I try an ease out that usually won't work, even with added heat. Being really careful not to break the ease out off in the hole.


Note how well the Harbor Freight drill bits cut the grade 8 bolts by the shavings they leave. The bits are not so hard that they break off in the hole. They just bend if you side load them. I have a nice set of titanium bits but the least side load and they will break off in the hole.


44 assorted bits were $7.00, what a deal!


After drilling three times, trying a ease out, trying cherry red heat, welding on a nut and washer, nothing has worked on these three 5/8 bolts. In the morning I will burn them out with oxy acetylene down to the threads, then I will use a pick to unwind the threads out of the hole and then clean up the existing threads by running a tap through them. For the best outcome in a situation of this sort it is best to do such a delicate burn out operation when you are fresh and have plenty of patients. If I fail to burn out the bolts and clean up the threads then I will drill and tap oversize to 3/4". I would rather not have to do that.

Sometimes you come out better to just cut the lights, lock the door behind you and go to the house before you screw up something and make it unfixable. Tomorrow is all mine and a new game begins, old man VS machine!

 

[Nitelite]

The three 5/8" bolts that I am currently working on are shown on page 36 of this thread in post #527. By far, they are the toughest to deal with that I have encountered.

 

[mopar65]

I have the roller frame laying on its side in the shop. The three 5/8" bolts are the ones located under the tractor that attach the roller frame to the loader frame. The first thing that I did was to grind the broken bolts level with the surface as shown.

View attachment 137308

Next, I drill through the bolt and out the other end. At this point I don't know what method I will use to remove the bolt but once drilled, I can not loose center of the bolt later on.
View attachment 137309

Next I drill twice more with successive bigger bits. I try an ease out that usually won't work, even with added heat. Being really careful not to break the ease out off in the hole.
View attachment 137310

Note how well the Harbor Freight drill bits cut the grade 8 bolts by the shavings they leave. The bits are not so hard that they break off in the hole. They just bend if you side load them. I have a nice set of titanium bits but the least side load and they will break off in the hole.
View attachment 137311

44 assorted bits were $7.00, what a deal!
View attachment 137312

After drilling three times, trying a ease out, trying cherry red heat, welding on a nut and washer, nothing has worked on these three 5/8 bolts. In the morning I will burn them out with oxy acetylene down to the threads, then I will use a pick to unwind the threads out of the hole and then clean up the existing threads by running a tap through them. For the best outcome in a situation of this sort it is best to do such a delicate burn out operation when you are fresh and have plenty of patients. If I fail to burn out the bolts and clean up the threads then I will drill and tap oversize to 3/4". I would rather not have to do that.

Sometimes you come out better to just cut the lights, lock the door behind you and go to the house before you screw up something and make it unfixable. Tomorrow is all mine and a new game begins, old man VS machine!

nitelight that's what i did. me 941 had the same 3 bolts broke off. oh oh course i had to do mine with the roller frame still attached to the trackloader. after i drilled out all the bolt holes, i could not find my 5/8th tap. so i said the heck with it and drilled and taped them f0or 3/4 bolt.well i must of did something right, because that was last summer and they haven't feel out yet.lol

 

[Nige]

The three 5/8" bolts that I am currently working on are shown on page 36 of this thread in post #527. By far, they are the toughest to deal with that I have encountered.

When you have them warm rather than hot try melting some candle wax round the thread area. It ought to wick into the threads themselves right down to the bottom and make removal a lot easier. You should be able to spot the melted wax being sucked into the threads if you watch closely.

 

[Nitelite]

No such luck

When you have them warm rather than hot try melting some candle wax round the thread area. It ought to wick into the threads themselves right down to the bottom and make removal a lot easier. You should be able to spot the melted wax being sucked into the threads if you watch closely.

Candle wax didn't stand a chance with these three. They just never gave up. I ended up drilling to 1/2" and running a 5/8" tap through to clear the original threads.


It is done!


This roller frame has no broken bolt issues. I just needed to drop it down to provide access to replace the sprocket rim. I will reseal the track adjuster where it sits.


This rail is in the shop.


It just takes time to get around to all of it.


Someone has replaced the sprocket rims before. As can be seen in the picture, they did not remove the roller frames but rather cut the new rims at 10:00 and 5:00 and welded them back together as they welded them on to the old sprocket centers.

 

[Nitelite]

nitelight that's what i did. me 941 had the same 3 bolts broke off. oh oh course i had to do mine with the roller frame still attached to the trackloader. after i drilled out all the bolt holes, i could not find my 5/8th tap. so i said the heck with it and drilled and taped them f0or 3/4 bolt.well i must of did something right, because that was last summer and they haven't feel out yet.lol

Mopar, if you drilled and tapped those three bolts while you were laying under your machine, my hat is certainly off to you. That probably required a lot of resting between sessions. Oh my aching arms!

 

[Nitelite]

I have noticed that there is a lot of interest in the procedure of replacing track adjuster seals. I am taking quite a few pictures of the operation as I repack the adjuster pistons. It is easy to see with the roller frames off and starting with the front idlers pushed all the way rearward. I hope to get this entire procedure all on one page which will be page 42 of this thread and beginning with post # 608.

 

[Nitelite]

Rebuilding Caterpillar hydraulic type track adjusters.

I have noticed that there is a lot of interest in the procedure of replacing track adjuster seals. I am taking quite a few pictures of the operation as I repack the adjuster pistons. It is easy to see with the roller frames off and starting with the front idlers pushed all the way rearward. I hope to get this entire procedure all on one page which will be page 42 of this thread and beginning with post # 608.

Loosen the track adjuster relief valve about two turns. Push front idler all the way back by placing the draw bar pin in the sprocket tooth and backing up so that the track chain tightens up and pulls the front idler backwards all the way so as to expel all of the grease from the adjuster.

I am working with my track chain already removed, so that is how the pictures show this rebuild. Just to mention but not to confuse the issue, once the procedure is thoroughly understood it is not impossible to remove the adjuster piston without pulling the barrel out of the spring thus eliminating the need to split the track if you can get enough slack chain.

Use whatever method you have available to push the front idler forward. My best method, considering that the frame rail is not on the tractor is a Port A Power. Normally you can pull the idler forward utilizing the loader bucket or in the case of a dozer, chain the idler to a tree and back up just enough to move the idler forward.


Remove the four bolts from the adjuster as shown


In order to remove the barrel from the inside of the spring the idler must move fully forward and then the barrel needs to be rotated about 1/4 turn to gain clearance.


It is close, but it will come out.


Now, you can extract the piston out the front or rear of the barrel. Actually, there is the option to leave the barrel inside the spring and use channel lock pliers to just extract the piston from the barrel. Clean up is difficult if the barrel is left in position.

 

[Nitelite]

Rebuilding the track adjuster continued

After removing the piston from the barrel note the spiral retaining ring that retains the seal on the end of the piston. Catch the end of the retainer with a small screwdriver and roll it off, replace the seal and roll the new retainer from your kit into place. .


Retainer removed


Use a small screwdriver and a hammer to wedge, pull apart and replace the two fiber colars as shown.


The rebuilt piston can now be lubed and slipped back into the barrel from the front end. A sharp whack from a hammer handle may be required to persuade the new seal to recede into the barrel.


As pictured, the remaining o ring and the nylon ring seal the front end of the barrel where it bolts the barrel to together at the flange. In the picture the new o ring is fitted with the nylon o ring fitted over the top of the rubber o ring with the tapered side down against the rubber. Coat those two o rings with a film of grease to hold things in place during final assembly. Note, the larger o ring fits inside the flange opening before re fitting the barrel into the spring. The purpose of that larger o ring is to seal dirt from entering around the outside of the barrel.

 

[Nitelite]

Track adjuster rebuild continued

Replace the newly rebuilt barrel and piston assembly back into the spring.

This large o ring might be rotted and missing when you disassemble. It fits inside the lip of the spring opening, just before the barrel is refitted.


My kit for the 951. About $25.00


The resealed piston fitted back in its barrel.


By whatever means available to you, push the front idler rearward to bolt up to the adjuster flange. You can push the idler back with the loader bucket or a bottle jack against the dozer blade. I, again, use the Port A Power.


Last, close the relief valve on the track. Pump new grease in to tighten adjuster. Crack the relief valve to bleed any trapped air and close it tight. Move machine forward to make the final adjustment.

Might as well do the other side while the tools are out and it is fresh on your mind. Hope this information proves to be helpful.

 

[jughead]

and people tell me cat parts are expensive. try a d 75 s komatsu kit just the outer dirt seal cost 140 plus bucks from the dealer. did find the complete kit else where but cost 5 times what u paid.

 

[dixon700]

I just read the entire thread you've done quite the amount of work to that old machine. My hats off to you. You'll have a great machine for many years after all the fine work you're doing.

 

[kshansen]

Nitelite, was flipping through an old book and found a picture of one of those track loaders you like! Looks like it would be fun to operate with those "short" levers.

Also note the high tech ROPS system.

 

[Nitelite]

He don't have a lot of computer problems with the old gal. He is really running some tight tracks also. There is a lot of difference between a sun shade and ROPS and I can't imagine the purpose of such long levers. Those guys really worked for a living!

 

[Nitelite]

Thanks for the reply Dixon 700. It has been an adventure for sure. It is almost too hot to work on the old gal with the thermometer busting 100. I did go out yesterday and rebuild the left track adjuster. Next order of business is to cut off the old sprocket rims. It will be tedious work cutting them off of the sprocket while they are still mounted on the tractor. An accurate cut line is a must and then there is the decision of whether to use oxy acetylene or a plasma cutter.

I am thinking to clamp the new rim to the old one. Get it turning and adjust until it runs true, and mark inside the new rim with soapstone and just start cutting. Whatever method I decide to use to do the cutting you can bet that my pucker power will be just about as tight as the tracks on the old T7 in the previous post above. I hope it is a measure twice, cut once type of deal.

 

[tctractors]

Nitelite, firstly we had some odd days of rescent with the temp' hitting up around the 36c spot, things are back to normal for our Summer around the 16-18 c so its still a bit toasty, on the rim cut task might I suggest you remove the outer cap from the hub, this is 6 bolts 3/4" AF socket needed,under this cap should be a load of grease also a centre hole in the end of the dead shaft, use this to scribe a datum cut line from, you also need to measure from the main frame to the inside of the sprocket the distance the rim stands out from this set point, do a bit of maths on the old rim width against the new rim width, then come up with the distance you need to be from the set point, after you have cut off the rim you need to weld onto the frame at the set point a strip of metal cut to the required distance, then throw on your hoop and tack weld away getting the rim to match up with your datum strip by running the sprocket around via the motor, I just use a tape measure with the distance needed Tip-Exe'd on, but I have done heaps of the re-rim stuff so have more confidence at this task, all credit to you for sticking at this job its not easy to get things going as its all hard work.

tctractors

 

[Nitelite]

Thanks for the tip tc. That sounds like a better approach than mine. I had considered removing the hub but was hesitant on the account of the possibly breaking another bolt. Sounds like it is worth a try, and I will. I am just in no hurry in the midst of all of this heat. My new sprockets and chain are a month old at this point and show no wear at all.

 

[The Peej]

where's the update?

 

[Nitelite]

Things are sitting just where they were. My heart problems prohibit my working in such a heat wave as we have had lately. It has been running 100 degrees and I need 70s or at least mid 80s to be able to proceed. All of the track frame work has been done. The new chains are rolled out under the machine. The sprocket cut lines have been marked out and ready to cut. I just need cooler weather to work in. For sure, I will update when I continue the project.