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Hello -- Getting ready for a first drive in my 31 Standard 8. But, I want to swap out the trans, rear end, and steering gear lube before doing so-- is there a one-size-fits-all lube that I can use for all three? The manual I have has vague information in it. Also, I want to clean and repack the wheel bearings -- Does the castle nut need to be torqued to any precise number or is it just to get it snug to the point where there is a slight drag?

I use Sta-Lube SAE 140 Gear Oil in my 9th Series, should be the same for 8th Series cars as well, available from NAPA but you may have to order it. This gear lube is good for yellow metals which are present in these cars. If you run your car in the cold weather, you may need to go to a 90 WT in the winter, but make sure it is good for yellow metals, not all brands are. I live in South Carolina so cold weather is not a factor. I do have to double clutch the gear box for the first couple miles until the oil gets a little temperature to it.

Would Valvoline 85-140 be okay for this application? I've seen information that it's a GL5 gear oil but doesn't contain the sulfur additives and thus yellow-metal safe. Any opinions out there?

I note no one has responded to the second part of your question about adjusting the front wheel bearings. I was taught to tighten to the point of the first bit of preload, and then back off a small fraction of a turn. You may want to first tighten snugly to make sure the assembly of bearings, races and seals are all seated, but then back off until you can just feel the slightest amount of free play. One way to do this by feel is, with the wheel/tire removed, grasp the brake drum and backing plate and rock back and forth; if the bearing adjustment is allowing just the smallest fraction of movement between the drum and plate, you have it right.

As to lubricants, mine is an 11th Series but I don't think the requirements are significantly different. I use SAE140 GL-1 (straight mineral gear oil + defoamer) in my transmission and steering gear box and GL-5 SAE85-140 in the differential. I've been using them for decades and no problems.

Owen - Thanks very much

Okay, I will try to blow the smoke away on this issue of mineral vs EP (extreme pressure) oil.

When Packard introduced the first Hypoid gear set the EP oil used was a lead based soap (or something like that) that was reactive with copper bronze alloys. EP oil is needed because Hypoid involves sliding action which creates boundary lubrication conditions (read metal to metal). So anything going into the differential must be gear oil (GL-5 being the current standard). 85W-140 means that when the oil gets hot it will not thin below what a cold 140 weight oil would be.

Some automakers were recommending motor oils rather than gear oils for transmissions as late as the 1970's, but that was going out the window as early as the 1950's; for example, 1952 Chevrolet was allowing EP gear oil for manual transmissions. Today the non-EP transmission oil is rated MT-1, but the Packard non-synchro trans is an all steel unit so EP is fine for it. Some people are dumping heavy stuff like EP 250 into those transmissions because they don't want to learn how to shift. Those heavy oils just serve to wear the engine out faster and rob performance. I used to bomb around in Hirsch's 745 which had like 90W EP in it and the gear whine was so loud cars would move aside thinking it was a fire engine. Billy used to drive it through NYC and the Holland tunnel in second gear. Totally awesome.

The steering gearbox has bronze it as do the chassis parts, but today's EP oils are probably okay (EP in the Bijur should work just fine, and, you may not know it but 90W gear oil is equivalent to 50W motor oil).

Why do I say all of this? Attached is the military specification for gear oils. In it is the non-corrosion specification for copper. If you read the label on these gear oils you will find reference to the MIL spec on the label. That is your assurance they are compatible with bronze parts. And besides, who knows what has been in these units over the years?

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