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whats best oil or lube?

I use John Deer corn head grease. It's a self leveling grease that will not leak. You can get it at a farm implement dealer.

Depending on the year, original spec was 90 wt gear oil. In '55-56, Chevy issued a service bulletin updating that to a semi-fluid grease, due to customer complaints of leaking at the seals. That grease is NLA. Today the best substitute is NLGI 00 grease, which is semi-fluid and self-leveling. There are a number of alternatives available, but not all have particularly good specs. I've done a bit of research as a result.

Many use the John Deere Corn Head grease, which is NLGI 0, and even though self-leveling, a bit thick, IMO. J-D hasn't published full specs, which makes it hard to assess and compare. Since it is designed for a power-transmission gearbox, it gets fluid with the stirring/heat in that application, which may not be optimal for a steering gearbox. But, results seem OK based on what others report.

Many vintage groups recommend the Penrite Steering Gearbox fluid from Australia. Surprisingly, it has lousy specs - by their own literature it does not meet EP minimums. Other fluids like the Champion "00" marketed by Eckler's and the Super S "00" available from TSC also have specs that aren't great. Turns out that not all greases of the same NLGI grade have the same base oil viscosity, and their consistency is determined by the amount of thickener (usually a Lithium-based soap), not the base oil viscosity.

Others use a home-mix of NLGI 2 chasis grease and gear oil. That can be made with about the right consistency, but may or may not provide good protection, and will be prone to separate. Even others suggest STP, which IMHO, has no place in a gearbox. By my way of thinking, a commercial product is preferable.

Long story short, there are brand-name greases that are NLGI 00 and that have very good specs. I chose Chevron Delo EP 00 grease, which is designed for gearbox applications and has great specs and a base oil viscosity that matches well the original 90 wt gear oil spec for my '53 Bel Air. Shell and Mobil have comparable products. The problem with all of these is that the minimum quantity is usually a 35 pound (5 gallon) pail. There is one fellow who markets repackaged Mobilux EP 023 grease, which has good specs, and is an NLGI 000 (thinner) semi-fluid grease, Classic & Exotic Services - Mobilux EP 023 Grease, but it's pricey.

If you want more info on the Chevron Delo EP 00 send me a PM. I have excess available since I bit the bullet and got a 35lb pail... data sheet from Chevron is here: Chevron Delo EP 00 Grease PDS.

Thanks for info classic & Exotic are close to my house will give them a call. Rebuilding 1941 chevy 1/2 ton gear box.If does not work out will give you a shout for some chevron.

1ea, sending you a PM.

While most people think of the so called "grease" in the gear box it is really more like gear oil. Real "grease" would make it to hard to steer.

You are right, chassis grease - NLGI 2 - is not what should be run in a steering gearbox. Not because it makes steering harder, but rather because the grease will channel and not flow back to the gear and bearing surfaces, allowing excessive wear.

The original spec was for 90 wt gear oil in most vintage Chevys that I have worked on. Older vehicles may have used heavier weight gear oil. In any event, Chevy issued a service bulletin update in '55 due to customer complaints of fluid leaks. The SB updated the recommended fluid to a GM semi-fluid, self-leveling grease (NLGI 00, near as I have been able to determine), which is NLA. NLGI 00 has the consistency of ketchup, so flows readily, but doesn't have the same leakage issues that gear oil may have in older boxes.

Current semi-fluid grease will flow and not channel, and does not cause hard steering, so is a great option for these gearboxes. I'm currently using Chevron Delo EP 00 (great specs, including base oil viscosity equivalent to 90 wt gear oil and great anti-wear properties), and have some excess (minimum available size is a 5 gallon (35#) pail) listed at my cost in the Services Offered by Other Members classified forum for anyone looking for some repackaged in standard grease gun cartridges or quart-size jugs.

I have successfully mixed 90 weight gear oil and corn head grease (50/50) before and a good friend for years and years used straight STP (the thick stuff). He claimed it was better for avoiding seepage (which no matter how hard you try these boxes at some point will do). As dreep above said, do not use chassis grease.