Hi all,
I've found this D7 3T with LeT cable blade but I need some experienced advice to decide if to buy it and restore.
I think it doesn't run for some years and the risk is that engines (both diesel and pony) and transmission may be jammed or have some inside rust due to water entrance.
Which are the easiest checks I could make to verify if it's restorable?
This kind of machinery is not very common in Italy and it's the third I see in my life, so I think it would be hard to find spares too.

I am still have some use spair parts for d7 serie 3t

I see a nice can over the exhaust!

If you can buy it for scrap price, then you won't be out of a whole lot of money if it isn't fixable after all. Many of the replacement parts for those old machines seem to be made in Italy these days:D There will be some parts that just aren't available new any longer. I would expect the LeTourneu PCU might be the hardest to come up with clutches for. You do have the double drum control there, so you could perhaps use the best parts from both sides the get the dozer working.

You want to check for water in the engine crankcase(s) and gear cases. One of the best ways to do this if you can is to loosen the drain plugs and see what begins to seep out as you loosen the plug. You can allow any water to drain and then perhaps catch a small sample of the oil that should follow to see what kind of condition it is in and look for metal debris in it. If it looks pretty good, I would wait to run the machine before draining and replacing so you can circulate the oil for a little while and remove a lot of the contaminants with the first change. Just have to be cautious what you start up with so you don't cause damage.

You will also want to check the cooling system for coolant or if none is present, check the engine and radiator tanks etc. carefully for cracks from freeze damage. If no coolant, fill the system with water and see what happens. Perhaps someone drained it.

Finally attempt to turn over the engines. Many old diesels can be turned by grasping the fan blade and turning it while holding the belt tight on the back side. One that has been sitting will most likely need a stronger method like a bar into the flywheel through the timing window cover or a socket on the crankshaft pulley bolt.

What is the serial number?

Tracks and undercarriage will most likely be the most expensive part if you can't use what you have. What are your plans for this tractor?

Post more pictures!

Thanks a lot for your reply.
First of all the owner is not completely persuaded to sell it, as his old father will not agree. Then if succede in the first step, it depends on the price and the status.

I'd like to restore it and make it run again in original conditions, but I have to estimate if it's possible and how much it will cost.

I just had a quick look at the machinery and took the picture I published. I expect to come there soon with much time and with definite things to check. I'll certainly check the serial number and the status of the things you suggested.
Furthermore I'll take some more pics to show the gear in detail.

Try to determine whether it got parked running or if something broke or wore out so that it could go no further. That bit of history could help determine what this is going to cost.

Yes, I'll try to investigate about the history!

Where may I find the serial number? I suppose somewhere on the chassis.

Look for a tag on the left side of the engine near the rear just under the head. If it's not there, look for 4 rivets. .usually the numbers were stamped into the engine block before the tag was attached. There's usually another tag, or stamped numbers on the left rear of the transmission but with the winch, those numbers might be covered.

Could be a 4T, used by the combat engineers in WWII, look for the serial number tag on the back above the final drive filler cap, left side.

Some observations from the photo, looks like it is missing the double deck sheave assembly on the LeTourneau PCU ( power control unit ), but aside from that, which is a non essential item unless you want to run scraper or other towed piece of equipment, it looks complete, heck you even have the lights on it, and the track pads look nice, you could measure the undercarriage to see how much it is worn, though it may be a wild assumption as many tractors this age are worn out, good pads can be on thin rails and worn pins and bushings, you may be surprised to find that it's got a good undercarriage.

I own 1 that looks just like that one, and another of the same serial number, one of my favorite models the 4T, as ordered by the U.S. Government for the war.


With the compresssion release on OFF, and the starting engine disengaged, master clutch disengaged, trans and forward/reverse levers in neutral you should easily be able to turn that diesel motor over by hand.

The LeTourneau PCU may be difficult to get parts for, but bearings and such may be able to be cross referenced, driving and driven cones may need new friction linings, though these are simple in working principle, a mechanically inlcined person should be able to adjust and repair one of these. Would not stop me from owning one.

The good thing about these is that they made about 50,000 D7 tractors that were about identical, subtle upgrades and minor changes before the 3T series ended, it is possible for this one to be a 3T, as that series started in 1944 and ended in 1955, 28,0000 + built 4T's were 1944-1945, 9999 built, previous series to the 4T, 7M had the same amount built, + the 6T and the 1T which were low production = about 50,000 D7 tractors of this almost identical series.



With that many, though you may have to import parts, you should be able to find most parts, + there are some still available, aftermarket and so on, was a popular tractor that was used in all kinds of applications, lot of em parted out in scrap yards and many probably gone to scrap, still a lot of sources to check, now is the time though, I'd not want to have a basket case needing a lot of parts in 10 years the way things are going. These make a great farm dozer and crawler, old, not all that powerful, but darned reliable.


The dry master clutch, is one of the only weak areas, still fine for a part time user, but you have to check that one out, not hard to pull, not sure about having it relined with friction materials, you must keep the pilot bearing greased with the appropriate grease, one that stays put, don't want to over grease ot it may get on the linings.


Also, there are a few important things to know about the starting motors on these, if you do not want to jeopardize it, or cause any damage to what is kind of costly to rebuild, I could at a later time describe what you should know, I like the starting engines and know that when properly taken care of and used, they are excellent for cold weather starts, and have other benefits, when not taken care of and or in good repair, they can be frustrating to some people.


Good luck with purchasing it, might be a decent tractor if those pads are any indication of the undercarriage wear, one of mine turned out to be a true low hour tractor with minimal wear on it, you can tell it sat in a military depot until 1970 because of the pitting in the track pads, and other signs, all add up, some tractors and hour meters can fool you, but they certainaly do exist, if it was used by the U.S. military and ended up in private hands after the war and not used like many were by contractors, could be possible, and in your neck of the woods, there probably are not many around, I don't often see them on this side of the pond and there were an awful lot of them around.


Also be aware that the best manuals for these are war department technical manuals, sometimes found on e-bay, complete books for this tractor, hard to find and a bit expensive sometimes.

they are a good cat and easy to work on. parts in north america are easy to come by. you can follow along as i work on my d7 4t with is the miltary version of the 3t.

kingofobsolete.ca/caterpillar_d7_4t_KING...OBSOLETE_WEBPAGE.htm


thansk
KoO
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