D-4 78a final drive

well once again chris, if it is the same as a 7u i got the part for you. already out and ready to go, final drives and etc. if someone can confirm this, he will one his way in no time. if it is for the dozer i saw of yours, then i am guessing yes it will work. another trip to ohio might be in my future.

From my aftermarket interchange info that is a "no go" with 7U

You need a 4K4632 gear.
Fits 39A, 40A, 78A, 20J, 83J1-3259, 84J
The matching pinion is a 9H6980

maybe someone can fill me in better on this one. i am a little confused as to where this part is on the machine that he is looking for.

JAKE my dad is looking at a d 4 78 a a little newer than my d 4 7u it needs a bull gear. I guess i am trying to get an idea on how much to fix it. I shure was hoping that your parts would cross. Did you get the lincon welder fixed? I bought a contintal engine manual on ebay. Do you still need one?

My mistake...I was thinking bevel gear not final drive bull gear😮 😮
Let me get back on that one.

OK, similar situation, "no go" on D47U
Different bull gear number is 7K4458
Fits 39A, 40A, D4C's
Fits 78A, 22C, 20J, 82J1-3237, 83J1-1800, 84J1-1382, D4D's

Can't help you with cost but shouldn't be to hard to find used.

Matching final drive pinion is a 7K4512 if you need one.

jaker65 - The bull gear is the very large gear inside the housing (ham case) that is behind the sprocket. This is the very last gear in the drive train, and is bolted to the sprocket shaft.
This gear is driven by a much smaller pinion that is located at the top forward part of the housing, and which is attached to, and driven from, the steering clutches.

As a result, these parts are known as the final drive pinion, and the final drive bull gear.

thank you Oz dozer! that makes it 10 times easier on me. I am sorry i do not have the part chris, i was hoping i did. i didnt get the welder fixed yet, the seal i bought is just too big. i am probably looking at pulling the crankshaft to repair the rear seal. If you do have the manual on it, that would a big help for me! hope to get to come down again sometime soon. I still havent got to that radiator yet. the weather just been so cold around here, that i would freeze my hands to the unit.

Chris, give this place a call and is in western Pa. and is Cleveland Bros. used Cat parts store.The # is (724) 325-9478 and ask for Den Tressler if he,s available when you call.Get the parts numbers ready so to save time.

Chris - I think the part #s you are looking for are
6K1022 gear and 5K1022 pinion. But I think those numbers
change to heavier gearing. Cat Product Bulletin Ma 20 -1972
Sorry can't help on prices Cheers Al