D4 7u40392

That would be "57" year model. Where are you located? Pic of my D4 7U41493 "57" year.

Oh, ya ,lol Iv'e had good luck after I overhauled an engine out of crane. Valves would be rusted up and which ever valves were open the cylinder was shot.

Hi Kyle,
the short answer is yes the engine can be returned to running order but... The longer answer is that all parts are replaceable, so for example, if the cylinder liners are unserviceable due to rust pitting, then you can put new/used liners in it. Likewise, the crank can be turned down. However, depending on how bad it is, it could be expedient (not to mention cheaper) to locate a good running engine (for example from a tractor that has worn-out undercarriage thus reducing its value). A disadvantage to engine replacement is that the engine and tractor serial numbers won't match - this would not satisfy a purist but you might be ok with it.
Step 1 is to assess the extent of deterioration in both engines and then we can figure which way to go. Drain the oil in each compartment and check for water contamination. The water should drain first because it's heavier than oil. Use two containers - if the oil runs clear after draining the contamination, then you can save the rest and put it back in temporarily.

For the pony motor, don't worry if it's seized - there are lots of them around and the cylinder block and contents are essentially the same through all the years of the D2 and D4 (they used the same pony motor) - if it's in bad condition, just pick up another one for a few clams and swap your peripherals over (manifolds, mag, carb, etc.).
Post pictures and share status and we can help with advice. Pull the pony heads and top cover and take a look. For the main engine, if it can't be turned over by hand, pull the cylinder head and take a look - post photos. Check all four clutches for operation (pony, main, left/right steering) - for the pony clutch, you can remove the main clutch cover and with the pony clutch disengaged, try turning the pinion end by hand (make sure it's not latched into engagement with the flywheel ring gear). For the main clutch and steering clutches, you can tow it and see if they operate correctly.
Post photos, post photos : )

Cheers,
Neil

Thanks for the information guys, im located on vancouver island b.c. canada . Im looking at buying this d4 for no more than scrap price if the owner agrees , its definitely had its fare share of use over the years, if i can get it and it's to far gone then ill look for another d4 and keep it for parts. If i manage to scoop it up then ill post up pictures as i work away on it.

Does this model of D4 have the forward reverse lever?

im not very familiar with it yet so im not sure

Anybody know if the D47U ever had a shuttle shift?

Never knew that 7U series had fwd/rev shift lever. Some operators refer to it as a Johnson Bar.