Caterpillar D2 D4 D3400 Pony Engine Crank Shaft

Showing 1 to 5 of 5 results

Lineshaft Restorations

Topic Author

Offline

Send a private message to Lineshaft Restorations

Posts: 23

Thank you received: 0

Greetings all.

New to ACMOC forum and new 1941 D2 5J owner as of May 2018.

I recently took the pony engine crank shaft 4B903 from my 1941 D2 5J tractor to a well respected N. Texas automotive engine rebuilder to have the rod journals reground. Both were 0.010" out of round. Each of the two had different measurements but were worn the same.

The shop said they would not touch it because the crank had been welded. The crank had been stamped 0.030 which presumably meant it was 0.030" under new dimensions.

Upon much closer inspection, I did see one crank throw had been welded. It was not a perfect weld but very good by my reckoning. There were some dings in the crank like the engine may have had a rod failure. In short something bad happened but it must have been repaired. In spite of the repairs this pony was not well cared for-lots of metallic sludge in the crankcase.

Anyway, is a welded crankshaft a good reason not to regrind the rod journals? There is plenty of material to work with. The down side is custom Babbitt inserts would have to be made. Anyone have any luck with a parts engine crank shaft? Suggestions? I'll post pictures once I figure out how to. Each forum seems to have different way of doing things.

Thanks, Patrick

https://www.youtube.com/watch?v=s9rpdPQ-4dc

Please log in or create an account to join the conversation.

Wed, Mar 27, 2019 12:46 AM

Old Magnet

Offline

Send a private message to Old Magnet

Posts: 16,696

Thank you received: 19

Get the crank magna fluxed. If not cracked get it ground with no guarantee.

Please log in or create an account to join the conversation.

Wed, Mar 27, 2019 1:43 AM

ccjersey

Offline

Send a private message to ccjersey

Posts: 4,422

Thank you received: 0

I think you are already into the custom bearing range even if you got it finished at exactly 0.040" undersized. My 5J3501-5J10561 book shows a maximum 0.020" undersize bearing.

I expect the welding would confuse the Magnaflux process anyway.

There should be better cranks out there. Lots of ponies coming off to convert to direct electric start. Maybe you would consider that? Old Magnet has figured out the measurements to bore the clutch housing and get the correct starter drive and nose etc.

If you want to keep the pony, the crankshaft itself and the complete block assembly interchanges between all the D2 models and all the 212 graders so there's a bunch of them out there.

D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time😄

Please log in or create an account to join the conversation.

Wed, Mar 27, 2019 3:04 AM

WA7OPY

Offline

Send a private message to WA7OPY

Posts: 217

Thank you received: 0

Reply to ccjersey:

I think you are already into the custom bearing range even if you got it finished at exactly 0.040" undersized. My 5J3501-5J10561 book shows a maximum 0.020" undersize bearing.

I expect the welding would confuse the Magnaflux process anyway.

There should be better cranks out there. Lots of ponies coming off to convert to direct electric start. Maybe you would consider that? Old Magnet has figured out the measurements to bore the clutch housing and get the correct starter drive and nose etc.

If you want to keep the pony, the crankshaft itself and the complete block assembly interchanges between all the D2 models and all the 212 graders so there's a bunch of them out there.

Some shops are over fussy, if you understand there will be no comeback if it brakes I see no problem in grinding it for them. Pony cranks should not be that hard to find. It might be a good time to convert to electric start and forget the pony...WA7OPY

Please log in or create an account to join the conversation.

Thu, Mar 28, 2019 9:46 AM

Lineshaft Restorations

Topic Author

Offline

Send a private message to Lineshaft Restorations

Posts: 23

Thank you received: 0

Reply to WA7OPY:

Some shops are over fussy, if you understand there will be no comeback if it brakes I see no problem in grinding it for them. Pony cranks should not be that hard to find. It might be a good time to convert to electric start and forget the pony...WA7OPY

I really want to keep the pony motor. It is nice not having to worry about a battery.
Besides I have invested time and money in its restoration so giving up now would not be a good thing.
If anyone has a lead on a pony short block with a decent crankshaft or just a crankshaft I would appreciate it.

Patrick

Please log in or create an account to join the conversation.

Fri, Mar 29, 2019 12:15 AM

d2gary

Offline

Member

Send a private message to d2gary

Posts: 1,282

Thank you received: 1

Reply to Lineshaft Restorations:

I really want to keep the pony motor. It is nice not having to worry about a battery.
Besides I have invested time and money in its restoration so giving up now would not be a good thing.
If anyone has a lead on a pony short block with a decent crankshaft or just a crankshaft I would appreciate it.

Patrick

I might have one that would be ok to grind. I'll have to pull one out of a block. Probably cant get to it until later this weekend

Please log in or create an account to join the conversation.

Fri, Mar 29, 2019 2:05 AM

Showing 1 to 5 of 5 results

Upcoming Events

View Calendar

Caterpillar D2 D4 D3400 Pony Engine Crank Shaft

Follow Us on Social Media

Upcoming Events

The Century of Caterpillar

Clarendon Classic

Chapter 18 100 Years of Caterpillar - Kingaroy

Yorke Peninsula Field Days

Testimonials