Re: Modern lubrication suggestions

Posted by Tim Cole On 2019/4/1 19:16:07

I never saw a rear axle specification prior to 1938 other than "See your Packard Dealer". From 1938 onward they specified 90w EP gear oil. There was a very good reason for the strange language. Packard pioneered the hypoid rear axle which requires EP - extreme pressure lubrication. So all Packard differentials from 1925 on require rear axle EP gear oil. Straight mineral oil is not an EP lubricant. Heavier than 90w will probably only create unnecessary power loss in the rear axle.

For the non-synchro transissions using heavier oils has been popular because it makes shifting a little easier for the novice. However, I like gear whine and always loved those transmissions with the standard oil. Using EP in the transmission is fine because they don't have any reactive metals in them. With 90w gear oil the shifting takes some practice, but the car sounds like a fire engine.