Hello there
I have been working on my D4,noticed its fitted with a WICO magneto.Also on the end of the serial number it says SP then US
During cleaning there is green paint under the yellow.
I have read somewhere that military D4 tractors were fitted with WICO mags.Can't remember where I read it.
Can anyone tell me if this is right?
Many thanks
Martyn

The SP on the SN means there is some special parts installed at the factory and some on here say it,s in the gearing but not sure unless there was a bill of material with the tractor which there wouldn,t be with an army surplus tractor.As for the US probably was made for the US army I,d think.I believe those older Cats had Eisemann mags on them but Cat used Wico on later tractors so they would fit the older start. engines I believe.

I have got a bit of work to do on the pony engine,compression is a bit low,will get the mag overhauled or replaced.The diesel runs very well,the track chain is nearly new,according to my track measurement chart they are new.Will post pictures when i resize them.Machine is not bad for 1942.
Martyn

Hello Martin,
You wil find most machines imported during WW2 were painted green, many rebuilt and painted yellow in later life. The WICO mag is probably a service exchange supplied by Bowmaker or Leverton in later life as well although the original was probably Eismann.
As for the SP, it is 'special parts' and in many cases it is a different gear ratio set for agriculture rather than earthmoving.
I know we had some on timber work many years ago which would pull anything in third gear while others had to go down to second, all down to the different gear ratios.

My machine is an D42T SP. Gear ratio continues to come up. Does anyone have an idea how to check to see what gear ratio goes with what machine.

The information regarding earthmoving versus agriculture is interesting. I suspect the agriculture would have the smaller gear ratio....any thoughts?

bernie

It was always my understanding that ag machines had a lower 3d and 4th ratio for ploughing and earthmoving higher gears for scraper towing. Top gear is the same as the input is locked to the output in top.
The US stamped separately on the serial number plate ws usually put there by the Cat dealer to denote an undersize crankshaft.

Hello Catsilver
Its another machine from Bill Butt,my mate may buy Bills Cat 955k,have you had any dealings with Bill's 955k? It has a ripper on it.
Martyn

Soory, I can't help much over that 955K Martyn, I've not seen it for about 10years when Bill was using it on a small tip not far from his house, I don't recall him asking about any problems with it though.
Most important, make sure there are no (or minimal) final drive leaks, the track frames bolts are tight and that the transmission doesn't overheat.
These were the main headache areas.

Thanks Catsilver

We have a 7J also with the SP and US7 stamp. I have heard the same thing of different gear ratios. I am currently looking for parts in the final drives. Both sprockets were ran loose on the spline. It also has OD paint under the yellow. Does yours have a cable blade? This one has one of those angle Letuorno blades.