My dad just picked up an old D4 from the widow of a guy who passed away earlier this year. The widow didn't know anything about it's history. The SN is 7U 38512. Can anybody tell me a year and/or anything else significant about this machine?

As high a SN as it is would probably be a later 1950s tractor as the next series the 39A & 40A came out in 1959. They were a good tractor and if in decent shape you can,t go wrong with one.It would be the wide gauge D4 and the 6U is the narrow gauge model of the same years built.The 7U started production in 1947 but my book doesn,t give specific years a certain tractor was made but as I said it is a high SN so was later made.

Thanks for the info.

hello bigkylewhite ,your d4 7u 38512 was built in 1956,weight =10500lb ,hp = 43 ,they built 44307 of them, 7u model has the d315 engine fitted ,bruce oz

You have a 1956 year , is it in good shape ? The bad thing about the that type tractor is when the master clutch wears out you have to pull the engine to replace it as i remember from years back . I my self would like to have a good D47U , they were good tractors .

Catman 580, no it,s not needed to pull the engine to change the clutch as we changed dozens of them at the Cat dealer I worked for and on later tractors they had a two piece cover over the clutch where the early ones had a long one piece that goes back over the steering clutches. We cut many of them on the earlier D4s so you didn,t have to pull the whole long cover.

The D4's in real good shape. Engine runs strong with good power. Steering works good. Tracks have a lot of life left in them. No oil leaks. Really couldn't find much wrong with it. Oh, the glow plug solenoid doesn't work - not a big deal to fix. He paid $4K and he's pretty happy with the deal.

SJ;
Your comment about cutting the long one piece top cover on the early D4
7U's got my attention. I just completed rebuilding the steering clutches, after removing and reinstalling this long one piece cover. Where and with what would you cut the top?? What would be used to reseal the top cover after cut??
Thanks for the info. Frank Gross

Instructions on D4 top cover splitting.
Can also be cut with sawsall.

Frank the dealer I worked for used to send them out to this machine shop and they cut it for them. I can,t remember if there was a bulletin from Cat just where to cut them or not. In the later D4 U series parts book they list 2- 3B889 gaskets to go where it was cut.I would think you could make up a gasket from material to go in between there to seal it and put some permatex along with it to help hold and seal it.Possibly if you looked when the cover was off you could see just where you could cut it. In the D4 6U11506 and up it looks like it,s cut down between the front and back of the valley in the housing and 4 bolts back from the front of the cover but you,ll need to leave enough material behind the 4th. bolt hole so it can be bolted up there in that area.I,d imagine a machine shop would have a band saw big enough to cut it as I never saw the shop we used how they cut it.Hope this gives you an idea of how it,s done.