Anyone ever seen a sprocket like this

[LT-x7]

I don't have a whole lot of experience with these but I've never seen one anything like this. How is it possible it wore off every other tooth?

 

[monster truck]

That is caused by the track chain stretching. When the individual links stretch, or the pins in between wear, they no longer match the distance between the sprocket teeth and will wear down every other one. By this same principal it is also common for dirt bikes to break every other tooth off of the sprocket. This is one of the more extreme examples I have seen on a piece of equipment though.

 

[LT-x7]

That makes perfect sense, thanks for the explanation.
Could it also be caused by running the track extremely loose? I know this machine has had a problem with the track tensioner for some time. It's amazing how much more wear there is on this side of the undercarriage compared to the other.

 

[QuickTrax]

What machine is this??

 

[monster truck]

It is much more likely to be from the track being too tight. Too much tension on the track will cause accelerated pin wear and stretch the links.

 

[OneWelder]

I suspect the chain was shortened because of wear - if you get a situation wear the # of chain links is divisible by sprocket teeth , the bushings hit every other tooth so same teeth always wear

 

[John C.]

That looks like an old excavator sprocket. I suspect the chain has been worn out for a very long time. Probably has many broken bushings and I'll bet the front idler support blocks are out the end of the track frame.

Really at this point it doesn't matter what caused it. It is so far past its useful life that who would even care?

 

[Dominion 410]

sprocket

Yep,they got the last dollar out of that one.Looks like a 200 series Cat sprocket.

 

[LT-x7]

It's an old 235c cat excavator.
I was just curious what caused it because I would assume if the sprocket was replaced the new one would wear the same way in a short amount of time unless the problem was corrected.

 

[monster truck]

It's an old 235c cat excavator.
I was just curious what caused it because I would assume if the sprocket was replaced the new one would wear the same way in a short amount of time unless the problem was corrected.

Correct!

 

[Komatsu 150]

I suspect the chain was shortened because of wear - if you get a situation wear the # of chain links is divisible by sprocket teeth , the bushings hit every other tooth so same teeth always wear

I'm sure this is the answer here. There is never supposed to be both sprocket and chain with both even or both odd numbers.

 

[monster truck]

I'm sure this is the answer here. There is never supposed to be both sprocket and chain with both even or both odd numbers.

The number of links and the number of teeth will not make a difference in wear as long as the space between the pins is correct. I worked for a company that removed a link from one track of thier excavator to shorten it. Almost all of the operators swore up and down that having a shorter track on one side would make the machine turn when it walked. Afterwords the machine walked as straight as ever.

 

[monster truck]

I suspect the chain was shortened because of wear - if you get a situation wear the # of chain links is divisible by sprocket teeth , the bushings hit every other tooth so same teeth always wear

The chain will Lengthen because of wear, not shorten. Either way it will have the same effect and cause the pins to no longer line up with the teeth resulting in the wear you see in the photo.

 

[mitch504]

The chain will Lengthen because of wear, not shorten. Either way it will have the same effect and cause the pins to no longer line up with the teeth resulting in the wear you see in the photo.

I think he means somebody took out a link, thus changing the ratio of bushings to sprocket teeth. This causes the sprocket to pull with the same teeth every time and half the teeth to never touch a bushing.

 

[JDOFMEMI]

I think he means it stretched to a point it could no longer be tightened, so it was shortened by taking out a link or two.

 

[monster truck]

Ok I gotcha, either way the number of links will have no effect on sprocket wear, the only thing that matters is the distance between the pins.

 

[mitch504]

Hey Jerry, don't you hate when somebody else is typing the same thing at the same time and makes you look like a copycat?
Mitch

 

[Komatsu 150]

The number of links and the number of teeth will not make a difference in wear as long as the space between the pins is correct. I worked for a company that removed a link from one track of thier excavator to shorten it. Almost all of the operators swore up and down that having a shorter track on one side would make the machine turn when it walked. Afterwords the machine walked as straight as ever.

When you remove a link the same same sprocket tooth will hit the same bushing every time it comes around. I'm not saying you're going to see much of a wear difference if the pitch length is correct but eventually there will develop a wear pattern. If the pitch is incorrect with a lot of stretch, I think the pattern will be much worse. My 2 cents anyway.

 

[OneWelder]

apparently I was not clear enough - I assumed you all could see the sprocket had been " Worn to Destruction" and pins and bushings were probably in similar condition
Try looking up hunting tooth sprockets, non hunting tooth sprockets
A lot of old machines - a lot of them Cat and International models, used a design where bushing hit every other tooth . when you turned pins and bushings you moved contact to the unused part of of sprocket
as far as wear goes it was found to be a lot better to use the whole sprocket

 

[JDOFMEMI]

Hey Jerry, don't you hate when somebody else is typing the same thing at the same time and makes you look like a copycat?
Mitch

:Banghead Yea, I just seen that. I guess good minds think alike. My problem is i open several threads, then browse through them, so if there is a new post, I will miss it sometimes.


Back to the U/C at hand though, and I bet the pins and bushings are in every bit as bad of shape. Certainly got their moneys worth out of them.