D4 7J cracked oil pan

Very common problem. Comes from the really poor design feature of mounting the equalizer spring directly to the oil pan.

Yup, OM is on the money. Cast iron is a rigid crystalline molecular structure and doesn't take shock loading or flexing well at all. It tends to have all the malleable and shock absorbing properties of a toilet bowl.

I get it's kind of a crappy design, but is there a remedy for this issue. Reinforcement? or simply replace with a hopefully good pan.

Maybe some insulating material such as UHMW plastic or brass sandwiched in between would help.

I would suggest an elastomeric pad of durometer hardness of at least 50 that is used in bridge bearings---either plain or reinforced with steel plates

Hey jmvmopar, I've got a pristine oil pan off of a D4400 power unit engine that I tore down for parts, it came out of a dragline. Actually now that I think of it I remember selling you the fuel pump drive gear from that engine a few years ago. It looks identical to a tractor oil pan, and has never touched a spring as the engine was mounted on skid type mounts. There is a "but" though, this D4400 is older than your 7J, it's from the 4G RD-4 era. I don't have the parts books or knowledge to verify if it would interchange with your 7J or not, but if it can be determined that it would, I would like to sell it and get it out of my shed, plus I'm not that far from you.

For what it's worth, by eye-balling the pan it looks identical to the one that's on a 5T near here, but of course that is far from conclusive. I can get the engine serial# and any casting numbers that might be on the pan if you're interested, but it's gonna have to wait for daylight first, lol.

Takes a s/n to check!!!!!!

OK went out this morning and got some numbers and pics, engine serial #4H327SP. Snapped a couple pics of the pan too as long as I was into it.


Casting number and numeral code, likely inconsequential but just FYI.

[img]http://i802.photobucket.com/albums/yy310/TRNelson/photo%20203_zpsiivbankr.jpg[/img]


[img]http://i802.photobucket.com/albums/yy310/TRNelson/photo%20204_zpschyb47fy.jpg[/img]

[img]http://i802.photobucket.com/albums/yy310/TRNelson/photo%20205_zpsjcmjvs8l.jpg[/img]

OK, that's half the s/n requirement, need the 7J s/n.
There is interchange but it takes a big jump to later 7J s/n's.