Here's how the CCKW oil filter turned black..

[pfarber]

The original GMC 270 provided from the factory has been documented as GM-1504314. This is the now classic gray 'AC Type' oil filter connected to the GMC270 via two clamps and the oh so sexy AC oil filter decals.

So why are so many engines equipped with plain jane black filters? How do you know what filter to order?

Well, its easy.

The Army decided that there would be three standardized oil filters to replace specific manufacturers filters when they were damaged or needed replacement. Thay are shown below:

They are, from left to right: Senior - Strap Mounted (FSN 8-F-1440), Senior - Base mounted (FSN 8-F-1335), Junior (8-F-1330). Note that they are black and contain no manufacturer or oil change instruction decals. Also note Senior Filter - Strap mounted has the oil inlet fitting directly in line with the oil drain plug. This can cause issues on the CCKW as once installed on a CCKW, the drain plug will point toward the engine and will make using a funnel to drain the sludge/oil very difficult.

The size and number of filters required was determined by the cubic inch displacement of the engine they were installed on:

Junior	Up to 224 cu.in.
Senior, Strap Mounted	225 - 300 cu.in. (GMC270)
Senior, Base Mounted	1 filter - 225-334 cu.in.
	2 filters 335-709 cu.in
	3 filters 710 - 799 cu.in

For the CCKW the element was PN GM-1595502 but if you read the SNL, it also shows the FSN of the 'generic' oil filter part number 8E-1010 and that is what you would order (remember that just because a part is listed in the SNL doesn't mean that its a stocked item... or even that it can be ordered via supply).

For giggles, the 8E-1010 cross references to civy part numbers:

AC	S-12
FRAM	C-31
Michiana	SA-12800
Purolator	PD-50 Series

So, when a CCKW or jeep goes to higher echelons for maintenance (repair or rebuild) and they need a new oil filter off comes the pretty gray filter with the cool decals and on goes a generic black military standard oil filter.

For CCKWs the 'tell' for an oil filter is the alignment of the oil inlet and drain plug. If they line up its a generic filter.. if they are offset, its the original factory filter.

[pfarber]

This use of the standardized oil filters was part of he Armys overall standardization efforts. These efforts were ongoing, but mid/late 42 was the time frame it was really hit the CCKW.

Other standardization efforts specific to the CCKW was the switch to negative ground, 40A 6v genny/regulator, the instrument cluster (remember the very first CCKWs, about 40,000 closed cab, had civilian gauges right out of civvy trucks).