Hi, I'm new to the caterpillar forums. I'm looking at buying a 1950's Caterpillar D4 for $7000 in really good shape for it's age, in my opinion anyway. The first question I have is what year is it? The Serial Number is 6U11416. My second question is, how difficult is it to replace the clutch? He said everything works great except the clutch will sometimes start to slip a bit when under load pushing dirt after an hour or so of operation. Once it sits and cools down its fine agian. He has had it looked at by a mechanic, and he adjusted it as much as he could, and said if it continues or gets worse the next step would be a new clutch. What do you guys think?

The machine looks great in the one picture but hard to evaluate from the one picture. Can you post more pictures showing the undercarriage, drive sprockets, front idler area, blade pins and pushing, many experts on here that can give you a decent evaluation if they can see it. Undercarriage repair/ replacement can easily cost as much as the machine. Before I would get to excited about replacing the clutch I would make sure that the adjustment locks on the clutch are not slipping so that it is loosening itself up.
Good luck
Roger

that is a 1956 machine---from the parts book diagram it looks like you can remove the coupling between the clutch and the transmission and pull the clutch out the top of the housing.

Thanks for all the responses so far, here are some more pics...

That unit has the oil clutch option.....you can see the dip stick by the right brake pedal.

"McMOPAR" wrote:

Hi, I'm new to the caterpillar forums. I'm looking at buying a 1950's Caterpillar D4 for $7000 in really good shape for it's age, in my opinion anyway. The first question I have is what year is it? The Serial Number is 6U11416. My second question is, how difficult is it to replace the clutch? He said everything works great except the clutch will sometimes start to slip a bit when under load pushing dirt after an hour or so of operation. Once it sits and cools down its fine agian. He has had it looked at by a mechanic, and he adjusted it as much as he could, and said if it continues or gets worse the next step would be a new clutch. What do you guys think?

Have no idea where you are located. Any time I see fresh paint I get scared. Probably not a bad deal but here in Tennessee I know where their is one about like it with no problems and good bottom for $ 4500.00

Still can not clearly see the drive sprockets for wear, or the front idler to see how much adjustment is left. In the one side view it appears that the sprocket teeth are almost rounded over but can not really tell. Take a closeup up of both front idler and rail and also of the rear sprocket teeth between the track and the frame at the front of the sprocket. Measure the overall length of 4 track links, (center to center of 5 pins,). Measure at a place where the track is tight. That dimension can be checked against the wear charts to see what percentage of wear there is in the track chains. A badly worn undercarriage can cost as much as the machine cost to replace.

As Roger stated not only take the 4 link dimension but also the rail height to determine how much wear.
The price sounds a little high--i bought a 1955 7U last year for $2100, and everything worked and drove it on a trailer--needed minor fixing here and there---undercarriage at about 50%-75% worn.

Thanks for all the information guys, its very much appreciated! I'm going to go look at it agian tonight, so I will take more pics and measurements of areas described. I called an old CAT mechanic today so I could get an idea of how much it would cost to replace the clutch if needed. He said it almost sounds like it is slipping all the time, and just starts to loose its pushing power when things get too hot and start to really expand. He also said its and 15 hr job at $100/hr plus about $1000 for parts, plus tax, plus transportation. So he said make sure you knock off about $2500-$3000 off the top for that. The machine for $4500 in Tennessee sounds great, its just to bad I live about 13 hrs away in Ontario, Canada.

Looks like those pads on the brake pedals are really worn down. This tells me they were using the brakes a lot. Ask the owner if any of the steering clutch components have ever been replaced. Do your homework before buying the tractor. You do not want to have "Buyers remorse" later on. Must my 2cents worth.