New D2 3J - Where to Source Diesel Piston Ring Set after Freeing Motor?

My advice is keep it simple Chris, unless you love hard work and spending money, you are off to a good start with the diesel / ATF soaking, you can clamp those cylinder liners down by using some steel offcuts, large washers, and the head studs, so you can watch your pistons move. I'd get some suitable emery cloth and hand scrub those bores clean of any rusty crud, wipe them clean, then try and roll the engine backwards after a good soak.

If you jack the tractor completely off the ground you can then roll the tracks with a suitable long bar wedged between the track plates, or if you don't want to jack her up, put the tractor in 5th, and very gently have a buddy pull her a few inches backwards with a winch block or slow strong vehicle. If you can go backwards then forwards very very gently, to "bump" those pistons free, you will be good to go. If they don't pop loose, light a fire in the bores, use a 50:50 oil and diesel mix, with a rag as a wick.

Once you have the pistons loose, you can then see if the liners are badly damaged, or they need a hone, or they are OK. If they need a hone, you can simply run a thick bead of grease around the outside edge of the pistons with them at bottom dead center obviously,  then hone the bores and give them a good clean out after.

Cat cylinder liners are made of the hardest steel on the planet, so don't be nervy, in fact Cat used to suggest using the powder kitchen cleaner Bon Ami poured down the inlet manifold, as a good way to bed in new rings and liners if they hadn't settled in on their own and were burning oil or slobbering!!

Once you get everything loose and clean, put her back together and get her out in a field working hard for a few days, you might just find you have solved all your problems. If, after a few days hard work you find she is burning a lot of oil, or slobbering badly, or hard to start, then by all means get a set of rings for her, contact Florin Tractor Parts in Sacramento, if they don't have them, they will know who has.

Now just to clarify, I'm no top flight Cat Mechanic like a lot of folks here, just a simple fella without a fancy workshop, but I have dragged a few dead Cats home over the years, one, a stuck 3 cylinder RD6 diesel that I couldn't get loose after several weeks of diesel / ATF down the bores, I filled completely to the top with used engine oil and let that sit for a few days so every internal part of the engine, like the crankshaft and camshaft, and timing gears, all got a good soak, and that worked. It took about 160 litres of old oil, but that is a big ol 9 litre engine!

Those early Cat diesels are a low compression diesel, and there is a heap of rings on the pistons, 4 compression and 2 oil rings, so even if your top ring might be nasty, you still have 3 more good compression rings under it, and I'm always amazed how well a worn out Cat engine starts and runs!! It's not unusual to re-use the head gasket too, if it looks alright, just give it a light coat of Permatex Aviation Gasket Sealer.
Good luck, and as I said, keep it simple initially.
Mike

Gentlemen -

Thank you for your input and responses, I appreciate it. More info to come in the upcoming weeks I hope.

Chris

If you do need rings Chris, that first one you list, 5B907, you need to add a zero to that part number for it to work in 2022, it is now 5B0907, the Cat part search function only works with a minimum of 6 digits.

I use both the Cat Dealer and the Machinery Trader website to search for parts, it shows who has those parts all over the world, and will usually show any updated or alternate part numbers.

I just had a quick look and the first 2 rings are available at Florin Tractor Parts and other suppliers, but the last one looks harder to find. They will be out there, if not off the shelf, there are piston ring companies that can supply them, I've had new rings made for my dead Cats.
Mike