The GMC CCKW

After an oil change I needed more than 12 gt to get the level to the minimum mark. And that's to much.
The dipstick appears to be a self made one, so I bought a NOS one which is slightly longer. Unluckily the corresponding tube was not available.
After another oil change the level is still a bit low with a 10 qt refill.

So I measured the length of the dipstick and tube.
Length of the tube is measured with a tape measurer by hooking it under the pan seam and measuring to the top of the tube. See pictures
Length of the dipstick is measured from the FULL mark to the collar.

In my case it is:
tube length : 15 1/2"
stick length: 20 7/8" (collar to full mark)
between min and full mark: 3/4"
so in my case the oil level (FULL mark) is approx 5 3/8" below the pan top.

It would be helpful if anyone could measure their tube and stick length for comparison.

Thanks, Bart

my 353 tube is 14" lenth of dip is from 18 1/2 from full to the stop on dip stick hope this helps

Bart,

I measured two engines today and found two different results. I'm off to a gun club meeting meeting tonight. No time to post results.

Pictures and measurements tomorrow.

Stand by. I think we may have found the root of your issue.

Cat Man

Pristus,

So your level is 4 1/2" below the pan top. That level is even higher than mine.
I guess that after so many years and so many rebuiltds the right level is difficult to reconstruct.
BTW my truck is a Banjo with two piece pan. Maybe it makes a difference.

Bart

Hello Bart,

Well, this took some digging but here is what I have found. There are indeed several different oil level dipstick combinations depending on the engine and truck.

Just to review the history. The early 270 engines prior to S/N 270 266551 had a shallow one piece oil pan. The dipstick is on the right side, forward of the distributor and enters the engine thru a boss on the cylinder block casting. Oil capacity was 11 1/2 US Quarts. The DUKW always retained this shallow pan.

After engine S/N 270 266551 the G508 vehicles CCKW and AFKW changed to a deeper two piece oil pan. The oil dipstick tube was moved aft of the distributor and enters thru the side of the oil pan. Same dipstick as on the shallow pan. Oil capacity in the new pan was reduced to 9 Quarts (LO 9-801) at the same time.

Later yet, a sheet metal splash guard was added to the right side of the engine for the Cab Over AFKW trucks. (The DUKW engine also has this but the dipstick remains in its original forward location). After AFKW 8429 and CCKW 394677 the sheet metal splash shield was placed on all the engines. Many have been removed over the years, but if you have an engine that was once equiped with this sheet metal, and the two piece deep pan, the dipstick is aft of the distributor and is SHORTER than the non shielded "tall" dipstick arrangment. This is because the shielded engine dipstick comes up thru the sheet metal guard and remains under the top cover. I have one of each engine here and measured both to confirm the differences. The engine ignition coil is also in a different location between these two arrangments.

Take a look at the illustrations below for dimensions and take note of where the top of the dip stick is compared to the spark plugs and cylinder head top edge.

This information was confirmed thru the last edition of the ORD 9 parts catalog and and lot of paging several other CCKW and DUKW publications until it made sense.

The oil quantity is a little confusing as well. In TM 9-801 it lists
7 1/2 Quarts - Filter not drained - Element not removed
9 Quarts - Filter drained - Element not removed
10 Quarts - Filter drained - Element replaced







Double check you equipment and let us know what you find. Sorry I did not use my metric measuring tape (but I do have one!)

Cheers

Cat Man

Thanks Catman, this really helps.

My engine no is 270 186598 and should have the shallow pan. But it has the deep 2 piece one and no shield. It doesnt surprise me because its a rebuilt ex French army truck.
It has clearly the long dipstick because the tube is exactly 17,5" as you mentioned.
The new NOS dipstick which I bought recently is almost to your measurements; the collar to full mark is 22 1/16" instead of your 22 5/16".
I consider the difference of 1/4" between dipsticks as acceptable war time tolerances.

I am happy now to throw the old (too short) bubba made dipstick away. Or give it a second life as a hanger for paint jobs.

Thanks again, Bart