D2 pony crankshaft thrust bearings

Well it’s been a long time since I posted about my D2 pony motor, but I’m happy to report that it is all together, running and starts my Diesel. I’ve got a couple hours on the pony and its working good. My new design (search previous posts) for controlling the crankshaft thrust loads went together well. I determined that I did not care for the way the thrust was controlled all from one end, so redesigned the way it works. It was my opinion that the crank pounding back and forth on the main bearing ends is what caused the locating dowel to fail allowing the bearing to spin and close off the oil port, thus causing the bearing to fail and allow the crank to jump around until it snapped in two. By using two large sintered bronze thrust washers and machining the case and rear end cap to fit them in, I now control the forward and rearward thrust from separate ends of the crank. The main bearings were rather pricey, so I made my own out of 6061 T6 aluminum as discussed by others on this site. It was a lot of spin work and careful measuring, but they were free so worth my time. I found a used crank on this site and polished it up. I had to re-sleeve one cylinder to refit the standard piston I had and that went well. My local Cat dealer here in Wisconsin (FabCo Cat Rental) was able to get all of the gaskets and seals I ordered. That’s amazing to me for a 60 year old machine, but easier than going elsewhere. I can drive up to the door and pick up my parts. I’d put them on the parts resource list. Piston rings are from Hastings, but I only saved about $30. I didn’t take too many pictures of the job, but here are some. Thanks for all the support and advice. We were successful.
PS. OM, It looks like the pictures didnt upload in the right order for me either..


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I like your thrust bearing solution.....probably should have been built that way to begin with. What did you settle on for thrust clearances?

On that pony flywheel, I'd recommend finding a replacement. That missing chunk is probably big enough to affect the balance.

Thanks OM,
The original design made no sense to me. I was shooting for about .015 inch but ended up with .020 after final assembly.
As heavy as that flywheel is I figured the broken out chunk was better left alone. I thought of drilling some holes opposite the break to guesstimate balance but decided against it. Maybe I,ll find a flywheel someday.
I appreciate your help.
Now I need to get the Diesel running right, but that will need to wait till Spring.

Nice improvement, When I got my D2 the thrust could have been measured with yard stick, you could see the crank floating in and out as it ran, in my case the dowell pin was missing.

when i rebuilt mine 10 year ago i locktighted the mains and dowels in, then crossed my fingers and hoped it would stay. lucky i don't run my machine but average once a month. u done alot more than cat woulda done back in the day. good luck

Nice job! Thanks for posting the pictures too!

Chad Enyeart

With an upgrade such as you have done, profits would have dwindled as far as repairs, parts, labor etc.