The crankshaft on my 5J series D2 pony motor has about 1/4 inch end play. It seems to run fine, and I just never noticed it before. Is that any kind of normal?

Yes that is normal, right before it throws a rod and ruins the pony. You really need to fix that, it is running on borrowed time.

Do a search on this forum, there are several threads that deal with endplay/main bearings.

i had probably 8/10 d2/4 ponies apart, most because of endplay issues. all the ones with excessive endplay was due to missing front main bearing retainer dowel pin. all were found in the bottom of the block. about half these blocks had a crack in the retainer pin area which caused a loose pin. the very first pony i did in my d4 15 years back had this crack. i loctite the pin in and carefully used 2 drops of jb weld in the small oil resevior, 1 front and 1 rear. so far so good. good luck.

ag-mike - I understand the Loctite on the pin.

I'm not clear on the two drops of JB Weld in the oil reservoir. Do you mean you close off the two oil passage holes in the bearing, one on each side of the hole for the pin? If that is what you do, wouldn't that limit oil flow to the bearing? Also if I'm right, I assume you put the JB Weld in without the crank in place? If you did so with the crank in place, wouldn't the JB Weld flow down into the oil hole and lock the crank in the bearing?

I think I'm missing something. I can't figure out where else you might have used the two drops of JB Weld, though.

Please help, I need to do this for my 3J pony, which lost the pin probably thirty minute's run time after I rebuilt it.

Thanks,

Pete.

do not block off oil holes, the pin is flanged, i carefully tried to capture the flange of the pin to the front and rear edge of reservoir, the other oil holes are right and left of the pin. some of the blocks i worked on appeared to be center punched in the area of the pin as to try to clinch the pin tight in its bore. to me this was done in the field because maybe the word was out about these pins coming out. to me there isn't enough or designed cast iron in the area to center punch clinch the pin tight. most recent case my welding machine pony retainer pin was kinda clustered f..... up. it had alot end play, the pin was out and the larger bore for the pin flange had been center punched to small causing the flange not to seat all the way down. its like they punched it small and then tried to install the pin. if it doesn't bottom out in the seat it ain't gonna stay. good luck

call if u want, i don't communicate well in writing.

That is very helpful, ag-mike. I got it clearly now.

I was sure I was wrong about using the JB Weld on the oil holes, but I couldn't imagine where you were actually using it. Your explanation about the field treatment of the blocks and the overall problem makes it completely clear. Your recommended procedure is:

Clean up any modifications such that the pin will seat with the head firm and in good contact with the block boss.
Loctite the pin shaft into the bore to give it the best chance of staying in.
Use a drop of JB Weld on each side of the pin head to further help bond and retain the pin head to the block boss, which it should be contacting well.

Very helpful and clear. I'll need to do this soon before my very low hour rebuilt pony becomes a boat anchor with extra ventilation holes!

Thanks again for the help,

Pete.

"Garlic wrote:

That is very helpful, ag-mike. I got it clearly now.

I was sure I was wrong about using the JB Weld on the oil holes, but I couldn't imagine where you were actually using it. Your explanation about the field treatment of the blocks and the overall problem makes it completely clear. Your recommended procedure is:

Clean up any modifications such that the pin will seat with the head firm and in good contact with the block boss.
Loctite the pin shaft into the bore to give it the best chance of staying in.
Use a drop of JB Weld on each side of the pin head to further help bond and retain the pin head to the block boss, which it should be contacting well.

Very helpful and clear. I'll need to do this soon before my very low hour rebuilt pony becomes a boat anchor with extra ventilation holes!

Thanks again for the help,

Pete.

thanks 4 ur hekp

I opened up a pony motor and found roll pins substituted for the problematic pins. Appeared to be working ok but I don't know how long it had been in service. Anybody able to comment on the alternative? Seems it would be ok maybe with some lock tite? Still would have the oiling function.

were the roll pins taller than the reservoir sides? the original pin with its tiny flange sets down low in reservoir and has its own oiling hole. seems to me it should been engineered more better to keep the pin in. back then it was only press fit....