Re: Gear Lube and Bronze/Brass Redux

Posted by Tim Cole On 2012/8/21 7:32:10

Dear Pat:

You do not have to worry about EP additives in your transmission. It is all steel.

However, the unit requires SAE 160w summer and 90w winter. Some people put 250w in them, but Packard warned against too heavy an oil - especially in winter.

I don't know how 85w-140 performs, but you can get 160w from Lubriplate or PittPenn.

For the case of Synchro transmissions, I tested copper in GL-5 and found that it did react. However, I usually found that most of those transmissions were running for years with EP in the transmissions so whatever damage was to be done had already occurred. For cases of shot synchros the GL-5 seemed to improve shifting, but the synchro transmissions are all living on borrowed time which is why I like the non-synchro series Packards best.

Also, modern EP is less reactive than the old stuff, but a call to Mobil found they concurred that GL-5 is still reactive. The Military spec for GL-5 being bronze tolerant notwithstanding.