Caterpillar 935CII track tensioner repair

[jwalk2c]

Thank you all for this great forum and your generosity.
My 1993 Caterpillar 935C II s/n 5DJ00157 suddenly lost track tension on right side.
I was able to pump it back tight, marked the position as shown in photo, operated for aprox. 10 minutes and the tensioner has moved back about 1/8 in.
I then opened the bleeder and grease did flow out, and from the picture you can see that tensioner moved back about 1 inch more.
So now I have both tracks jacked up and loader on blocks. I found the alligator type master link and rotated track to a position I thought might be good for taking track apart.
I have searched and read all I could find on this subject but it’s not clear to me what all needs to be taken apart.
This will be the first time I have split tracks or repaired track tensioner, and before I start I have a few questions:
1.What is best location of track position to spilt track, and do I just simply remove 4 bolts holding the pad that has the plus molded on it?
2. After track is split do I pull idler forward to end of rail to remove yoke shaft from cylinder asy.?
3. Will removing the 4 bolts on seal cover allow me to remove seals?
4. How do I access the cylinder #18 in parts diagram? And is it necessary to remove #18?
5. Does anyone have access to service manual and procedure? I know I need to purchase one but just cannot at this time.
Thank you for any help you can offer.
Johnny Walker

 

[DMiller]

First item of note, the recoil spring assembly will need be caged and removed for this little operation, while in there the rail will have to be split and yours does have a split master link, replace these bolts on reassembly. The idler will need come off the rail truck to remove the adjustment rod and mechanism. Get the tractor up on heavy blocking as a first start, You may wish to measure the rails but by appearance they are pretty well toast. And yes a service manual is of the utmost importance right now as the recoil assembly is dangerous on its own let alone never having taken one off.

 

[jwalk2c]

Thank you very much for the reply.
I was able to get a copy of the procedure from a friend at Cat. It is media number SENR3547-00.
It instructs to remove idler, and yoke assy. and the four bolts holding the head assy.
In side the head there is one seal and ring.
The pictures in this bulletin do not show the spring caged, but in the normal position..
Is it possible that SIS is wrong on this? And somehow left out the step of caging the spring.

btw; Thanks for the tip on the rails. I do need to learn how to measure them.
If I send more pics of the sprocket and rollers , can you give me an ideal how much more damage I will be doing running these rails?
I am only using this loader for my personal use and I probably will put no more than a 100 hours a year on it.
If I knew engine and transmission will hold up I would not mind spending money on rails.
The 3204 cranks easily but does smoke at times,and has blow-by.
I have ran about 25 gal of fuel and the oil level has went down a quart I would guess.
I do not know hours on machine as hour meter was stopped at 4100 when I bought it.
Oil pressure stays up and temp is good.
But not knowing history of engine, and my lack of experience, one can only guess how long engine will run.
Thanks again
Johnny Walker

 

[Nitelite]

Johnny, considering all things when talking about old iron, the engine smoking and burning a little oil can be considered a minor problem. I overhauled my loader engine when it was using two and one half gallons of oil every three to four hours and that gets expensive! I have not needed to add any oil since the engine overhaul. new rails, pads and sprockets weren't that bad either. My track adjusters were much easier to overhaul than yours seem to be. I had to do the dozer and loader track adjusters (four adjusters) as they all seemed to start leaking at about the same time.

Run old iron WOT today and don't worry about tomorrow, shik happens, just curse it a little bit and fix it as it happens, then run some more with a the wind and a smile on your face as she survives and talks to you one more time. Sometimes I even catch myself answering her. After all, there are still plenty of guys out there with picks and shovels, but man, look at you now!

 

[DMiller]

Appears yours is different to what I am accustomed. I can agree the four bolts should allow access without caging the spring after looking closer at the instructions. Just be careful around that recoil unit, they are unforgiving.

 

[Twisted]

Leave the tractor on level ground or you'll have to lift everything into place. Be careful as that chunk is heavy. No blocks until time to reassemble the master link. For this operation I split the track on the front idler, usually a little below center. Do not monkey with the big nut (#3) on the other end. Pull the idler/yoke/rod assembly out of the spring and tube. The seals on the end of the rod are the ones that have failed. The ones by the four bolts are basically dust seals and wear guides.

I did run into a dozer this summer that had a cracked rod but replacing the seals is the usual fix.

2-3 hours an a hand lining stuff up for reassembly will have you in the dirt again.

For an older machine for personal use, just run it with the rail and engine issues you spoke of.

Good luck and have fun!

 

[jwalk2c]

Thank you Mr.Miller for your advice and wealth of knowledge.
That spring reminds me of heavy truck spring brake chamber 'springs". I worked in parts at an International Truck Dealership for 35 years and there was always warnings and stories of the someone unbolting the clamp by mistake and the spring doing catastrophic damage.

 

[jwalk2c]

Appears yours is different to what I am accustomed. I can agree the four bolts should allow access without caging the spring after looking closer at the instructions. Just be careful around that recoil unit, they are unforgiving.

Thank you Mr.Miller for your advice and wealth of knowledge.
That spring reminds me of heavy truck spring brake chamber 'springs". I worked in parts at an International Truck Dealership for 35 years and there was always warnings and stories of the someone unbolting the clamp by mistake and the spring doing catastrophic damage.

 

[jwalk2c]

Leave the tractor on level ground or you'll have to lift everything into place. Be careful as that chunk is heavy. No blocks until time to reassemble the master link. For this operation I split the track on the front idler, usually a little below center. Do not monkey with the big nut (#3) on the other end. Pull the idler/yoke/rod assembly out of the spring and tube. The seals on the end of the rod are the ones that have failed. The ones by the four bolts are basically dust seals and wear guides.

I did run into a dozer this summer that had a cracked rod but replacing the seals is the usual fix.

2-3 hours an a hand lining stuff up for reassembly will have you in the dirt again.

For an older machine for personal use, just run it with the rail and engine issues you spoke of.

Good luck and have fun!

Thank you very much, I have enjoyed working on this machine.
So I can split track and pull idler forward without raising it off ground?
And if I understand correctly; the yoke shaft should pull out of spring area after I remove the head with the 4 bolts?
Then after repair raise it off ground to re-attach master link?
I have it on small blocks now but plan to visit sawmill and find larger timbers.

 

[jwalk2c]

Johnny, considering all things when talking about old iron, the engine smoking and burning a little oil can be considered a minor problem. I overhauled my loader engine when it was using two and one half gallons of oil every three to four hours and that gets expensive! I have not needed to add any oil since the engine overhaul. new rails, pads and sprockets weren't that bad either. My track adjusters were much easier to overhaul than yours seem to be. I had to do the dozer and loader track adjusters (four adjusters) as they all seemed to start leaking at about the same time.

Run old iron WOT today and don't worry about tomorrow, shik happens, just curse it a little bit and fix it as it happens, then run some more with a the wind and a smile on your face as she survives and talks to you one more time. Sometimes I even catch myself answering her. After all, there are still plenty of guys out there with picks and shovels, but man, look at you now!

Thank you for the encouragement and I agree with you 100 %. Over the past 30 or so years of building 2 houses, both on wooded land, and heating with wood, I have struggled with trees, with not much more than a chainsaw and a couple trusty Wheel Horses. Got a small 4WD tractor a few years ago, and this was a huge help, but this loader has been an immeasurable improvement. It cleared more in a few Saturdays than I had previously done my entire life (exaggerating)
Bought this loader almost a year ago, and before I put it to work I have been determined to go over everything I could repair or service. I don’t want to bore you with listing all but when I look at my records I have accomplished a good bit, but much more on the too do list.
Thanks again,
Johnny Walker

 

[DMiller]

If just splitting master link and breaking track won't need on blocks, but do set a block to catch the rail as it rolls off the idler. I use a come along to hoist the rails on my tractor up and not allow them to roll back off the top rollers, a short section of 3/8" link chain with two pin on hooks attached across a track pad makes a great handle to hook into. When you pull the split link bolts and track pad, replace the bolts on reassemble, cheap insurance.

 

[Nige]

If you have a contact at the Cat house maybe it might be an idea to have him download the procedure for splitting the tracks for you like he did for disassembly of the tensioner.

 

[Master Link]

The recoil spring should be in a capture position now. In the picture of your spring at the front of the spring on each side you see the spring stops? With these in place and the spring pushed against the backstop it's not going to go any place. Now if you wanted to take the spring out that a whole new story but you don't need to do that.

What your Cat dealer says sounds correct but I remember working on a similar type set up that we ended up having to drop the roller so we could pull that head off the cylinder because there wasn't enough room to pull it straight out. This was on a D4C or D5C which I know is not what you have but the set up is the same.

James

 

[little johnny]

I have replaced yoke and shaft on 931b new not available now can't get piston to depress shaft only goes in 4 inches needs another 4 repumped to make sure piston was free and repushed with 6 ton excavator stiil won't retract

 

[wosama931b]

I think there are a couple old thread on the recoil springs , the new replacement is a little different from the old . sam.

 

[jwalk2c]

I just finished installing the seal on my 935C, but I was able to push yoke/shaft back in by curling the bucket with 5 foot 4x4 to push yoke back in.Like you I needed about 4 more inches of retraction. This was my first job and it was a learning experience. I should have had the valve open that expels grease, before I did this, where did all that trapped air go?
It must have put extreme pressure on new seal. I will post pictures this weekend, but I think my cylinder and yours are different
Johnny Walker