Berco rails

Replacing a link is quite a job even if you have the correct equipment. Is the link worn enough to affect the integrity of the chain? Are you going to use the machine daily or just a few hours a year? "Loose" can be subjective so can you get a photo of the rail? Might be possible to ream it out and install a bushing to save the hassle of changing the link if the link is otherwise OK. .
On the other side I don't know of many Berco parts left anywhere unless by chance you could find on laying around somewhere.

another way could be to fill the holes with bronze and re drill to size. is it only one hole that ovalled or have they all ovalled on that link?

it is possible to rebuild grousers too by welding a piece of medium tensile bar to each grouser using low hydrogen rods.

Grouser bar is the correct profile and steel alloy for building up grousers.

Before looking at replacing links I would cut the old bolts out, grind any burrs flat and then put new bolts in and torque them up to the correct tension. You would be surprised how big an oversized hole a correctly torqued bolt can hide. Bolts in track plates and links are not a machined fit so they have a small amount of clearance even when new. Even better would be to fit a replacement shoe on it with new torqued up bolts. I have done this several times with good results provided all burrs are removed and the holes in the plate are not worn dish shaped then they usually stay tight indefinitely..

Grouser bar is the correct profile and steel alloy for building up grousers.

Before looking at replacing links I would cut the old bolts out, grind any burrs flat and then put new bolts in and torque them up to the correct tension. You would be surprised how big an oversized hole a correctly torqued bolt can hide. Bolts in track plates and links are not a machined fit so they have a small amount of clearance even when new. Even better would be to fit a replacement shoe on it with new torqued up bolts. I have done this several times with good results provided all burrs are removed and the holes in the plate are not worn dish shaped then they usually stay tight indefinitely..

Thanks for replies. This looseness is the track shoe bolts. I have not removed loose shoe yet. I like the idea of oversize bolts, that definitely may fix it. The shoe plates are thin, grousers have been built up in past with bar. This is a case of old shoes being reused on new rails I think. Shoes are just wore out. Couple are cracked and bent. The current shoes are 18". I'm wondering if new shoes are available. I believe these are 1/2" in bolts.

What are your intentions for the machine?
If it's just one or two grousers and you intend using the machine with the current undercarriage for a year or two still, then I'd just weld the grouser to the link for the time being. Nothing you can't cut loose at a later stage.

fit new bolts and see what it feels like the bolt are probably worn a bit too metal on metal rubbing wears both parts. did searc for grouser plates a couple of yrs back and the cat parts system did have a listing for the part numbers still. so new grousers may still be available. would be a bloody expensive exercise though. one thing about worn grousers they wont grip aswell if the going gets tough more likely to slip so less likely to strain something in the driveline and break a part that isnt available anymore. you can rebuild anything if you have the ability or the money to spend.

I will look for good used shoes or aftermarket new if available. Either way I will use new bolts. I do know of a set of used but brand new looking shoes. 2 problems with these shoes is they are 13" shoes. Also I suspect it would be 31 shoes per side, its an ag tractor ,and my machine currently is 32 per side. I would prefer the 18", but this used set is very low mileage.

a good used set may just be the right choice but something to remeber are you going to earn money with it, or just do a little work around your place or demonstrate it at a event or is it purely a display machine. if its just a display machine and only needs to move itself on and off transport then replace the loose bolts and leave it alone. no need to create work for yourself and the resulting hole in the wallet.