1939-1940 Caterpillar RD6/D6

3 cylinder diesel

Ex-military

This is a rare, unusual Cat, very suitable for restoration.
It looks like a shortened RD-8, a nice size for hauling.
The engine is essentially half of a 6 cylinder RD-8 of the time,
so it should be expected to have substantial parts commonality.
This is the second series of 3 cylinder RD-6/D-6,
with the shorter fuel injection pump and a bit more power.

Not running, but the diesel is free, and the pony is soaking.
There is no apparent reason it shouldn't run easily.

Master clutch looks good, lever snaps over as it should.
Steering clutches have a lot of material left, although the
steering clutch forks need work.
Everything is there except the seat cushions.

Pins and rails are excellent, no visible wear on bushings.
It rolls very free. One pin is partially broken, possibly
due to getting a stone.

Tin is good, some manageable dents, but very little rust,
as somebody has kept paint on it.

This was originally a military crane Cat, with a swiveling
Silent Hoist crane above the center. The crane was removed
before we got the machine, although the PTO gearbox is still there.

This machine would have spent its life in a depot environment.
As a result, it probably didn't travel very far on its tracks,
accounting for their excellent condition. Track plates are the
original old style street pads, with slots for bolting on grousers.

It has the oval fuel tank, normally located in front of the driver,
with the tube through it for the fuel injection lever.
Due to the crane frame, the tank had been relocated behind the seat,
but can easily be put back in front of the operator,
as the tank mounts are present.

An interesting restoration would be to reinstall a Silent Hoist
crane, as the same unit was commonly used on wheel machines,
and should be available in a boneyard.

Undercarriage is longer and possibly wider than standard.

We bought this rare Cat for restoration, but too many other
projects prompted its sale.

Copyright 1999 Dave Merchant
www.nesys.com