Running out of options I have a question about bearing material. I have two pony blocks for my D47U one has so many freeze cracks and repairs but still leaks so I've gutted the good parts and lean back to the original block that slung a rod. I can bore and sleeve the cylinder but the bearings have spun in the block has anyone ever made a new bearing from 660 brass or 932 bronze or even delrin? I know the aluminum bearings are original but having spun the new ones don't fit correctly. Should I give up and try to get another block or try to loctite them in place? The locating pins are missing and I'll make new ones to fit if i can't get them. Getting some part numbers together to have my local Caterpillar dealer see what is available. The cracked block did offer a good crank and rods that should polish up fine. Had a couple different people offering blocks but never heard back from them.

I did buy some 660 years ago to do up a pony. May need it soon. That was suggested to me by an old time machinist.

I have made bearings for D6 pony,same set up larger size. Bronze with babbit lining cast in and machined to size. Not really difficult and working for me. You may need to bore the housing slightly oversize and make a custom size bearing.

660 aluminum would be preferred and easiest on the crank journals.

I am still have a poney block 5f9341 for D2-D4

you can use loctite quick metal to bond the new factory bushes in to place. check the bearing housing with a bore guage and micrometer comparing against the new bush outside dia to make sure the wear is within what quick metal can take up. loctite super bearing mount or 609 retaining compound are other choices if the gap is tighter than what quick metal can do.

REMEMBER for loctite to work properly mating surfaces must be spotless and oil free. clean parts with thinners and follow with the loctite cleaner.

a forum member had posted pics of a set of bronze thrust washers he had made to prevent the crank end float problem that ruins the bushes and breaks magneto gears.
it was really well done.

here's a tip given to me by an old farmer and machinist make a couple of timber wedges to support the pony flywheel when it not running as the vibration of the machine and the flywheels heavy mass can cause the crank to pound out the bushes the flywheel side in particular.

You have one for sale or looking to buy one?

I think the factory material would be 6061 T-6 AL. I would stay away from Delrin as it will absorb water and can cause swelling. if I was doing it I would just get the holes in the block to clean up so you got a nice round hole then just make a custom main bearing. quite simple for a machinist or someone that can do a bit of lathe work. I made a custom size one for my #12 grader as my crank needed work so I just added the clearance to the bore.