Standard Rear End

[Guest Rick Nolen]

I have a 37' Zephyr with the std. rear end, what would be the proper fluid for this?

[Phil Knapp]

I believe that 1936 and 1937 Lincoln Zephyrs used a "standard" rear axle gear set. From 1938 and later, the rear axle gearset used "Hypoid" gears.

My experience with early Fords indicated that 90 weight gear oil was specified.

I'm attaching lubrication specs from the 1939 Lincoln Zephyr owner's manual and a Texaco publication. Both indicate that 90W is used.

Here in Texas, where it gets HOT, I've been using 140W gear oil.

If your rear axle leaks, 140W won't leak out as fast as 90W!

[Mssr. Bwatoe]

i am using new synthetic 75-140 its great..........i though i missed something so...i tore it back down after 1 year..5000 or so miles...looked clean as a whistle..nice and quiet.. lots of new cars use it..i put in my trans too....

[Guest DADDIO65]

I am an Amsoil freak... I use straight 140 weight in my 39. Although there was never any "whining" in the gears, I like the fact that there is no breakdown @ 110 degrees in a Cornhusker summer. Just my preference though..

[DavidAU]

As your rear axle is fitted with a Spiral Bevel type crown wheel and pinion you should NOT be using any type of oil made for Hyphoid type rear axles.

I looked at the Penrite oil site and see they recommend Transoil 140

I also looked up the Ford service book and in accordance with service bulletin 4000, April 15, 1938, the rear axle oil should be drained and refilled every 6 months or every 5000 miles.

I dont think you will find many people doing that these days.

David