Identifying Master Pin vs. Master Link

[ke6gwf]

general rule of thumb is if its pitted replace it that being said its all up to you. what does your cash look like for parts. can you afford it if not clean it up best you can and hope for the best. it may last 10 min it may last 10 years so its up to you. personally i would replace it with a new one. recroming is also an option dont know the cost or how well it will adhere and someone on the forum will be able to tell you better on that subject of recroming.

I don't know what parts of the shaft are exposed or are bearing/sealing surfaces, but if the rusty section is the seal area and the turned down portion doesn't need chrome, I would go to my local cylinder fab shop and have them chop the shaft off at the yoke, take a new piece of shafting, turn it properly and weld it on. I know my local shop can re-rod a cylinder cheaper than they re-chrome. If the necked down portion is a seal/bearing surface, than ignore me!

 

[Tommy]

Wow, thanks for all the good info.

And please excuse my ignorance, but this is all new to me. I have no idea what kind of chains they are, but will look for an I.D. Pretty much had to burn the old master pin out all the way to the bushing on both sides to get it out. The replacement master pin is from Komatsu and looks like it will fit. Not sure if all the pins have dimples on both sides, but I'll check. They definitely do on the outside. The dimple on the new master pin I bought is a larger diameter than the dimples on the other pins. The old one had been hit with a hammer enough to flatten out the end where you couldn't really tell what it looked like prior to install. It does have a dimple also.

I can afford a new shaft if that's what it takes. I don't really want to do this again unnecessarily. The pitted area on the shaft is in the area of the seal. How much movement is there in the shaft other than when you're adjusting the track tension?

Regarding the final drive seal, I'm assuming that's what is leaking based on where i'm seeing the fluid. It started leaking right after the track went slack and almost came off the machine before I realized what was happening.

 

[Tommy]

John, the seal is accessed from the outside. It took a 2 foot pipe wrench and a sledge hammer to get the nut off the spindle. I made a puller for the hub and it took some serious stuff to get it to break loose. After that the seal was a snap. I've never seen a seal like it. 2 o-rings mounted inside 2 separate metal flanges. The two flanges meet in the middle, being pressed together by the o-rings (see photos). It's hard for me to see how they will seal it, but we'll see. Still haven't made a decision on the yoke shaft coming out of the track adjuster.

 

[John C.]

Nice job on pulling the flange and getting to the seal. Those types of seals are called duo-cone seals. The biggest keys to installing them are making sure the landings where the O rings sit are absolutely clean and not touching the metal rings with your bare fingers. I take a rag and dip it in oil to coat the rings before assembling the parts.

Thanks for the photos. I didn't know that flange came off.

 

[Tommy]

Nice job on pulling the flange and getting to the seal. Those types of seals are called duo-cone seals. The biggest keys to installing them are making sure the landings where the O rings sit are absolutely clean and not touching the metal rings with your bare fingers. I take a rag and dip it in oil to coat the rings before assembling the parts.

Thanks for the photos. I didn't know that flange came off.

No problem on the photos. The parts manual showed the seals going from the outside in. The last thing I did was smear a coating of oil on the rings, but I did it with my finger. I suppose if there's any dirt on the mating surfaces, it's gonna leak. I know I touched them, so should I tear it apart, clean the rings and do it over? I haven't even bolted the sprocket on yet, but the hub is nutted on. Probably would release pretty easy since it's just been put on.

 

[John C.]

Don't worry about it. Motor oil on your finger won't hurt anything. The body oil on your skin is what gets them.

 

[dblaneyfan]

Put your master pins in a deep freezer for a day or two before you start to drive them in, it helps out just a tiny bit.