Hi Folks,

I have found a 1942 D4 for sale locally at a decent price ($500 to be exact). As a matter of fact the machine isn't but four miles from my home. This is somewhat fortunate for me since I have no good method to transport any iron of that weight. However, there are a few problems associated with the machine.

First off, this is going to be my first Caterpillar. Second, the owner mentioned that one day he was running the tractor and noticed aluminum flakes being expelled from the exhaust. At that point the machine was running on three cylinders. The tractor has not run in over a year. The pony motor is beleived to still run. Third, the undercarriage is a bit hammered. Fourth, the oil cooiler has been bypassed due to a leak.

As far as the engine itself goes, do these engines have sleeves and what are the pistons made of? I am not experienced with these machines, but have always been intrigued by them. Are parts for this machine prohibitively expensive? Any insight on this would be appreciated. Thanks!

Aluminum flecks in the exhaust is not a good sign, means a piston is going/gone south.
Bypassing the oil cooler is a very common solution to a leaking oil cooler and is not detrimental to operation (Cat eliminated the oil cooler in the late D4 series)

Undercarriage parts have a broad range of interchangeability among most all the D4's but can be pricey to buy new. All of it is readily available.

Engine parts for the D4400 are another story. Pistons, rings and liners are still available (after market) but bearing sources have just about dried up.

Prices will probably shock you. A visit to the Cat store for me usually runs about $300 for a lunch bag (not full) of incidental parts.

It sounds very much like a piston breaking up as that,s all that would be in there to throw bits of aluminum out.Yes it has wet sleeves in it as most all Cats do except a very few like the 1100s & 3100s & 3208s.Not sure on the very old gas engine tractors & engines. It should have the old D4400 engine 4 1/4" bore in it.I,m sure someone on here will come back where you can get parts for it.

Have a look at this thread. www.acmoc.org/ACMOC_BB/showthread.php?t=577

I never heard much about a piston coming apart until I started in on this D333, and everyone chimed in with their experiences. Look at the picture of the D333 block and IMHO do not run that D4 even for a trial run. It could turn into a mess quick.

Hi Folks,

I took a closer look at the D4 today. I guess the owner was impressed that a 19 year old kid was interested in his dozer haha. Fortunately I had my youngest brother with me to brush the snow off of it. The blade is (my guess) a good 8ft wide. Not only does this machine have a blade, but a Hyster winch marked "D4." Also, the owner mentioned that the machine came out of PA, perhaps an oilfield rig? The pony motor is also electric start. Also, the owner replaced one of the pistons, which he still had in the bottom drawer of his toolbox. Looking at the piston, the crown looks quite damaged, perhaps due to too much fuel, an injector problem as mentioned earlier? I am wondering if the piston is bothering on the same cylinder as before.

Also, Would anyone happen to have an approximate weight on this machine? What might I expect for a price on a new piston and rings? If not genuine Cat, someone had mentioned there are some aftermarket outfits producting pistons and rings? Would it be possible to obtain a decent used piston and sleeve from a parts machine otherwise? Thanks!