Changing Track adjuster Seals on a Cat 939 .

[ianoz]

Can anyone help with the best way to change the track adjuster seals on a Cat 939 .Most of the excavator ones we have done had a bolt on head with the seals in there . This just has an open end tube that the rod goes into .
There is a seal, i assume is just a wiper seal in the end of the tube.
Problem is , the tube is almost hard up against the front track frame support.The Chrome rod goes though a hole in the support. Does the Track frame have to be removed . Or does the recoil spring/adjuster assemberly come off without the recoil spring Taking my head off .

 

[Bob/Ont]

Split the track pull the idler out, inspect the idler rod surface. Dig out the seals and install new ones.
Later Bob

 

[ianoz]

Bob , The end of the track adjuster tube is almost hard up against the track frame support ,It is a struggle to reach though it to get your fingertips to where the first seal is .Only a small hole though the support to get at it .

 

[Nige]

Mate, Bob's right. To get at that seal (there are 2 of them actually, plus a fibre wear sleeve - items 5, 6, & 19) you have to first split the track, then pull the idler & tensioner piston clear out of the cylinder. At that point you can go in and dig the old seals out and replace them. See diagram below - the "View of Area C" is what you're looking at. If you want a full procedure for the job then PM me your machine Serial Number and your e-mail address.

 

[nzpatch]

Check the chrome rod for pitting, mine (d3c) was very bad from the dirt sitting on the frames around the hole that it goes thru.and when we put new tracks on leaked so got new seals and chrome rod welded on. All good for 700hrs now.

 

[Bob/Ont]

Bob , The end of the track adjuster tube is almost hard up against the track frame support ,It is a struggle to reach though it to get your fingertips to where the first seal is .Only a small hole though the support to get at it .

Okay Ian, you can drop the frame down away from the hard bar or clean and tighten the nut on the recoil spring bolt and try to get the spring and pilot out. Think dropping the frame might be easiest and safest.
Later Bob

 

[ianoz]

Thanks Bob , see how we go with it .
Some photos of the track frame .Looking down from the top .

Hole you got to work though to get at it .

Recoil spring end of the Adjuster .

 

[Bob/Ont]

Ian, are you sure of where it was leaking? I have seen some of those pilots crack at the weld holding the cyl to the plate.
Later Bob

 

[ianoz]

Definately from the seal end Bob .

 

[1466IH]

I thought that those would be built more like the 963's and such but they are like the older style adjusters. I would leave the track together and pump up the adjuster enough to compress the Sprin then remove the brackets holding the spring after I wrapped a chain around the track frame and spring and then when you let off the adjuster it will let the spring out then remove it all and repair. I just did this on my 951c. Mine was leaking bad enough though that I also had to help compress the spring with a 1/2" chain and ratchet binder

Sent from my SAMSUNG-SGH-I317 using Tapatalk

 

[Tuckerdog]

Ian, are you sure of where it was leaking? I have seen some of those pilots crack at the weld holding the cyl to the plate.
Later Bob

Bob, mine appears to be leaking from the weld cracking. What’s the simplest way to fix this?

 

[Nige]

Sorry to tell you this but Bob/Ont passed away a few years ago. https://www.heavyequipmentforums.com/threads/bob-ont.58226/

Try posting a photo of the leak location. A machine Serial Number would also help. With that info someone ought to be able to help you.

 

[Tuckerdog]

That’s awful. He had helped me before.

It’s hard to get a picture of where it’s leaking. I haven’t torn it down yet. Just with my fingers gotten below the grease cert area and it’s leaking there, not on the end where wipers may have failed if I am seeing the diagram correctly. If I reach up from underneath where the track rollers are, I can get grease on my fingers just beneath where you would install the grease.

I had the undercarriage replaced maybe a hundred hours ago so it’s all new less the tensioner, so I hate to tear it all down again if I don’t have to.

Serial is 06DS02004

 

[Welder Dave]

Bob was very helpful to a lot of people and is dearly missed.