Identify Case 850d master pin on track chain

dandugi

New User
I need to replace the seals on the track adjuster, but I cannot identify the master pin. All the pins are identical, there is not one with a marking or a drilled center. There is this one link in the chain that is different than the others, image attached. I don't want to start a sledge hammer on the wrong pin.
cvphoto94457.png
 
Some rails have a split rail "Master" held together by the four pad bolts.

Usually there open to get to the nuts like the rest, but you can see the serrations of the two half's.

Yours looks different but I bet you pull those pad bolts and it will separate.
There probably tapped blind holes.

Secure the track with a come a long first.
Tom
 
You got the SALT tracks (sealed and lubricated track) on your machine, you do not remove a pin, like TGP says remove the pad from the link in the picture and the track link will split, that type track will not split by removing a pin as the shoulders of the bushes ride in a boss in the link carrying seals to hold in the lubricant.
AJ
 
Well the next problem I have is that this joint (master link) is welded on the other side of the machine. That track tension seal doesnt last longer than 10 minutes. I don't know
what my options are other than cutting it off and then having to replace the chain on that side.
 
(quoted from post at 16:00:40 07/13/21) Well the next problem I have is that this joint (master link) is welded on the other side of the machine. That track tension seal doesnt last longer than 10 minutes. I don't know
what my options are other than cutting it off and then having to replace the chain on that side.

I would take the bolts out to get the pad off, secure the chain in a manner to get the strain off the master link, then try to AirArc or grind the weld off, before I just cut and destroyed the link.
 
At best you have a mess. You probably can grind the weld off but those old links are notorious for the bolt that holds the pad (and the rail together) twisting off. Get a good heavy 6 point socket and heat that link right where the bolt goes and then a long bar. Maybe you will get lucky. I am perplexed by your comment that the seal only holds 10 minutes, looks to me like you have never replaced the adjuster seal.
 
Steady up, no need to cut anything off, take the pad off out of the way, use a 4 inch grinder and grind off the weld, with a sealed and lubricated track it is not the done thing to remove any of the pins as the lubricant gets lost and the seals damaged, special filler required to fill it with oil again, if you think you can replace the adjuster seal then you are fit to grind off a bit of weld and give it a few wallops of a sledge hammer and split the track, clean up any blurs from the alligator teeth and its ready to go back, four new bolts and a smidgen of anti seize on them, before you damage anything find out the price of a new chain.
AJ
 
Thank you everyone for the good replies and advice, I will probably give it a shot with the grinder then next week, too much rain this week. I've only had this machine a few months, but I'm slowly getting
things on it going again (fluids, filters, rebuilt angle blade cylinders, replaced a few hoses, etc). I'll try and post back later what success I have if any....
 
Well as my late father used to say none of us was born under one and everything is a learning curve I have but in a lifetime in the repair business starting off before hydraulics were common and every thing was cable operated, your 850D is a long track dozer, if it's got the blade mounted inside the track and you can't get to the link on the inside you could consider slacking off the adjustment fully, get the slack in the track to the front and take it off the idler without splitting it and pull it to the side so you can pull the idler out, pump out the piston of the adjuster and reseal it, I should not have told you that way as I am supposed to go by the book, the book is right but sometimes when a fully equipped shop is not available one has to make do with what's on hand, remember nothing falls up but everything will fall down and with equipment everything is heavy so don't trust things like blades or buckets to stay up if something is accidently loosened.
AJ
 
I was curious if this would be possible, I don't know exactly how much slack would be available though. This 850d is not a long track. I am guessing that it would not be very easy to take on or off without
splitting, given the weight of the track and all. It might not even be possible with the shorter track.

cvphoto94601.png
 
That is a very decent looking tractor, the tracks look to be in good shape, I would say you would get the track to come off if you get all the slack to the front and the idler fully back, (I've had some drivers that would have that track off in seconds when it was not needed to be off) the blade will push the idler back and pull the track forward for you and I would say that it would come over the idler, there is nothing easy with equipment repairs it all takes a bit of muscle, swearing cussing etc to get things done, if you can't get it off you will have to grind off the weld, can you see why it was welded in the first place, if it has an issue it might be best to leave it alone and struggle to get it over the idler.
AJ
 
I haven't been able to get to the machine all week, rain every day, and its 30 miles away at the farm. I was going through all my pics, I did actually find one I took last week of the welded link, here it is.
Looks a bit worse, I see the pad was welded too. So I'm guessing the previous owners probably stripped the pad bolts out or something. I will see if I can get enough slack to get the chain off intact.
cvphoto94639.png
 
I'd agree with you that it is a bolt issue, probably stripped the threads, you can see it is a fairly amateur attempt to weld it but it's holding and that's all that's needed so it's best left alone, most of the guys on here tend to do it that way as out on the land track presses are not on hand and in lots of cases the track comes off on it's own, when handling the track watch out for the gap between the pads it's a bad place to have the fingers when they close, good luck
AJ
 

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