Packard Forum Index » Post-War (1946-54)

Hi guys, I'm looking at Penrite oils for my engine, manual trans and rear axle in my 53 clipper, and their website recomends...

Engine: Classic HPR30, (a 20w60 that sounds good to me)
Rear axle: Mild EP Gear Oil (a SAE140 GL4 also sounds good)
Manual Trans: Gearbox Oil 30 (Not certain about this one)

Anybody have experience with Penrite gear oil? I'll only be driving in warmer temperatures...the sae scale for engine and trans oils is somehow different?

penriteoil.com/uk/nextpage.php?navlink=

Dankesch?n!
Mike

Packard recommended SAE 90 gearoil which Castrol UK website crosses to ST 90. The only spec Penrite mentions is viscosity and has 24.4 @ 100 degress C. The Castrol ST 90 has a viscosity of 18.6 @ 100C so on that part, Penrite would appear to be in the range of acceptable and maybe even a bit heavier which might be good for the warmer times. There does not appear to be a direct correlation with SAE numbers I could find otherwise.

Unless you're living at the equator, I'd say a SAE20-60 is WAY to viscous. Try something like Shell's Rotella SAE15W-40 or Mobil's Delvac, suitable for just about any conditions.

Not familiar with a 30weight gear oil, but it's MUCH too thin for a manual trans. Manual trans and differential can be the same, anything from a single weight Extreme Pressure SAE 90, to 120, or a multivis EP SAE85W-140. I use the latter year round in both my 34 and 56, for manual trans, steering gear box, and differential and have done so for many years. I generally buy this from Valvoline in 5 gallon cans, any autoparts store should stock it or be willing to order it for you.

OK, 20-60 might be a little thick, That's what some of the aussies here seem to be running. (Germany is colder than austrailia I guess) I had run 20-50 in the past, and last year ran 15-40 diesel oil, and will most likely go back to a 20-50 non detergent oil. Castrol also has a 'classic oil here in germany that I can get locally.

I can use an EP oil in the trans also? It's not bad for the synchros? Then I might run this 'Mild EP' which is an EP GL3 140...

Oh, and regarding this 30wt = 90 wt business, if you go to
penriteoil.de/visko.htm there is a diagram that has transmission oil (Getriebe?l) and motor oil (motor?l)...I wouldn't run the same oil in my trans as the engine, that would be a little crazy, these ain't minis we're driving here!

Re motor oils, just keep in mind the trade-off, the heavier oils provide more "cushioning" but because of their greater resistance to flow they are poorer and transferring heat. That's the compromise.

I've used EP gear oil in all manner of Packard manual transmissions for 40 or more years, never an issue. I do recall those warnings from the 50s that some EP oils were not compatible with "yellow metal" (bronze, brass) parts in some transmissions. I suppose there was some truth to that at some point in time, but to my knowledge today's EP oils have no such restriction. If you are concerned, I suppose you could contact Valvoline or Mobil, etc. and present the question to them.

I'm using 85W-140 in my 48's gearbox and 80W-90 in the rear axle. 30W gear oil is used in vacuum pumps and industrial applications. I wouldn't recommend it for the axle.