seized D2 electric start pony and engine

Forum,
What are the possibilities of loosening up a seized D2 engine and electric start pony? What are the possible ways seizing happens?

Mr. T. Minnesota

The most common way an engine gets siezed is getting water down the exaust stack. The problem can vary from mildly stuck to a cylinder full of water and badly rusted. Many old Cats have been freed up and brought back to life. Pull the valve cover and make sure the valves are free, get something like Kroil in the cylinders. If starting engine is siezed too it is pretty easy to remove the heads and see what's up.

what worked for me is acetone/atv soaking for few days THEN VIBRATION can you put tension on crankshaft some way and vibrate the crank. Did this on F20 and was amazed just tapping on crank handel with high-lift jack pullimg up on crank handel

The first thing you need to do is think about what you want to end up with. If this engine is in a vehicle you really want to restore, then you have to understand that it's not going to be cheap project. I'm doing one of these engines right now, already crossed the 500.00 mark just between injectors and pony motor gaskets. Your engine needs to be removed and carefully disassembled. Do not mess with miracle lubricants or apply force to the crankshaft. Even if it does turn, the rings will probably be stuck in the aluminum pistons and you'll have to take it apart anyway. Why waste time and risk damage? In it's present state, it may be valuable to a Caterpillar collector, if it hasn't been damaged by force. There are plenty of guys at ACMOC who would be happy to give you a price if you should decide not to proceed with the project. Their knowledge is invaluable if you want to go ahead with it. You might as well go over there right now and find out how to make or have made an injector socket. Sooner or later, the injectors will have to come out. You won't luck out on this one, you must have the right tool. And a darn heavy one if they're stuck.

whats an acmoc?

Antique Caterpillar Machinery Owners Club

Got a rebuilt D2 pony ,new rings bearings and seals.Best offer.Also have a nice running 1948 d2 with blade and winch,all works nice but will only go in a straight line! Pony also runs good. Hoss

There are two types of stuck,water or dry.If water and set a long time bad rust and corroision can be the problem.If dry stuck,like inside building or covered exaust the whole time parked(not can blown off and replaced after a rain or snow)you might have a chance without a tear down.I have "busted" quite a few loose in my day,but chances are pretty slim its going to be a "user"