The GMC CCKW

I have a chance to salvage parts from a 1941 GMC CCKW. They told me I could take what ever I want, but the dash, because it was radioactive. What? Really? Comments please? Someone told me it might be because the instrument cluster had Tritium gages. Is that possible?

Yes, many WW2 instruments contained radioactive materials to give a luminescence under light critical circumstances. Sometimes it was the indicator needle only that had the substance applied, sometimes indicator marks or numerals.
As a source of radio activity poisoning, vehicle instruments have been largely disregarded because of the small quantity of material used and the fact that it is contained in a sealed environment unless accidentally or purposefully compromised.
Some fob watches also used radio active material and no one seems to make a song and dance about them despite the fact they were made to be carried on the person. You wouldn't carry one today but nor are they kept in lead lined containers to my knowledge.

David

Off the subject motto - I was wondering what oil is best to use in the transmission and transfer case - I have been using 80-90w but it has been suggested 85-140 would be better - thoughts?

Hi Sixbysix,

I have been using 80-90w but it has been suggested 85-140 would be better - thoughts?

I think a lot depends on the temperature of the environment you plan to operate the truck in.

This website shows some viscosity curves for various gear oils. Note that the viscosity for 85W140 is higher overall, but is much, much higher at cold temperatures than 80W90 .

https://www.widman.biz/English/Tables/gr-dif.html

Since neither the transmission nor the transfer case in the CCKW have oil pumps, they rely exclusively on splash lubrication to ensure that all of the gears and bearings receive adequate lubrication. With a higher viscosity oil, my concern would be that during warm-up, some internal components could become oil starved, due to the lack of oil being thrown around internally. This would especially be a concern if the vehicle was operated in colder temperatures.

This would also be of concern in the corporate (aka banjo) transfer case. The rear ball bearing for the rear, trailing axle driveshaft output sits in an extension housing, outside of the transfer case main housing. Gear oil has travel through another ball bearing in order to get to it. If the gear oil is really thick, it might have a more difficult time navigating that route.

Just my 2 cents worth.

Best Regards...