I guess I drive backwards a lot in my D6C...

I was looking at the bushing wear yesterday, and I noticed one bushing on the right side was worn way more than anywhere else on the machine. The profile of the drive gear tooth is worn into one bushing about 1/8" deep All the other bushings have normal wear. This almost looks like a machined pocket in the bushing...

I do lot of back blading, bad habit?

Why would only one bushing have this? I marked the tooth that makes contact with that bushing to see if other bushings that mesh have excessive wear, but they look ok...

Hi ETD66SS,
my guess is that the Belville seals have failed in that one unit and allowed dirt in to wear the pin, and the bushing internally.
To check this set the worn unit up at the top just between the idler and the first carrier roller and put a suitable pin into a sprocket tooth and back the machine up to tension the track enough to just compress the recoil spring, set the brakes etc and measure the pitch of the worn bush link compared to others around it to compare the wear results. See attach. see how you go.
Cheers,
Eddie B,

"edb" wrote:

Hi ETD66SS,
my guess is that the Belville seals have failed in that one unit and allowed dirt in to wear the pin, and the bushing internally.
To check this set the worn unit up at the top just between the idler and the first carrier roller and put a suitable pin into a sprocket tooth and back the machine up to tension the track enough to just compress the recoil spring, set the brakes etc and measure the pitch of the worn bush link compared to others around it to compare the wear results. See attach. see how you go.
Cheers,
Eddie B,

Thanks for the tip, I will try that...

The wear is only excessive on the one side (driving backwards), it looks normal on the other side (driving forward)

I may be wrong, but I think he is seeing wear on the outside of the bushing, don't know how you would see 1/8 inch deep wear on the inside of the bushing. My guess is there may be one bushing that wasn't properly heat treated before installation. Do you know if your chains are Cat, or aftermarket?? Some people have had big time problems with certain Berco replacements.I don't think it couldn't be caused by a flaw in the sprocket because the bushing doesn't run in the same sprocket every time around.

George

"trucker1" wrote:

I may be wrong, but I think he is seeing wear on the outside of the bushing, don't know how you would see 1/8 inch deep wear on the inside of the bushing. My guess is there may be one bushing that wasn't properly heat treated before installation. Do you know if your chains are Cat, or aftermarket?? Some people have had big time problems with certain Berco replacements.I don't think it couldn't be caused by a flaw in the sprocket because the bushing doesn't run in the same sprocket every time around.

George

I bought the dozer with 50% wear on the pins & bushings. I've since put about 300-400 hours on the machine (a lot of that is idling). No, they are not CAT chains... I don't recall what make they are...

I did not see this wear last year...

And yes, I'm seeing the wear on the outside of the bushing, but only on the front of the bushing, the wear you get from driving backwards... The other side of the same bushing looks fine as far as the wear pattern goes...

It's a combination....got a worn pin....worse on one side which allows the pitch of that link to be longer causing more wear between bushing and sprocket tooth for that link.

"Old wrote:

It's a combination....got a worn pin....worse on one side which allows the pitch of that link to be longer causing more wear between bushing and sprocket tooth for that link.

So instead of the wear coming from driving backwards, the sprocket is actually broaching the pocket on the bushing when I drive forward because the pitch is too much? That makes more sense to me...

This is the same side of the machine I got a 4" dia log wedged in there... Maybe I damaged a link somehow?

I was driving backwards off a pile and the end of the log mashed through the sprocket & chain mesh... It got stuck between 2 bottom rollers... I inspected the area after the incident, but didn't really see a problem. This was maybe 40 hrs ago...

I kinda doubt that chewing up a 4 in. log would have any effect.....the recoil spring should take care of that. At 50% worn you are probably passing through the heat treated zone of some of the surfaces, especially if quality control is not that great.

"Old wrote:

I kinda doubt that chewing up a 4 in. log would have any effect.....the recoil spring should take care of that. At 50% worn you are probably passing through the heat treated zone of some of the surfaces, especially if quality control is not that great.

Well, hopefully I can get at least 1 or 2 more summers (400 more hours...) out of the UC before I need to do anything...

I was just very surprised to see this wear already, as it certainly did not look like that when I bought the machine...

Anyone have a rough estimate on new sprocket segments & turning of pins & bushings for a D6C?

Just a rough idea...

Now that I think about it, yes, the links on my D6C are Berco... My 225 has the CAT links...

Once again, OM is right. I was thinking outside of bushing and forgot that there is inside wear of the pin and bushing too. sometimes I have a hard time wrapping my mind around two ideas at once.
Once again, thanks to OM and edb for adding to my education. Too bad I don't get any smarter.

George