Rockwell RC-33 planer / "extreme pressure oil"?

[David Peterson]

My first and, hopefully, last planer. I bought it in great shape from the original owner and it runs like a top. Even the knives came sharpened.
Question: What is this "extreme pressure gear oil" that is called for in the manual? Is there any particular brand or weight that I should use? Thanks very much.
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[James Baker SD]

Gear oil has additives that allow it to still work under "extreme pressure" such as the small space between meshing gear teeth. Motor oil has different additives that allow it to work under high heat conditions. Most auto supply stores will have gear oil in quart bottles. The weight scale is different for gear oil so (and this is approximate) 50 weight gear oil is similar to 90 weight motor oil.

James

[Larry Edgerton]

There are gear lubes made for racing applications that have a greater impact strength. Basically it squishes out slower.

One that is commonly available and would be awesome for such an application is Redline Shockproof.

We used a lubricant in our off road race truck differential that was $140 a quart. It helped the rear diff take the landings behind a 900 hp motor, and was worth every penny.

Redline products are reasonable, and available at just about any parts store worth walking into.

[Peter Quinn]

Most manufacturers selling these 15" Asian import planers recommend any 70W-90W hypoid gear oil. Costs about $3 per quart at most auto parts stores. Delta's special gear oil sold by the pint was almost $45 with shipping from them when I inquired. Criminal. I have been using castrol for years and it works great. If it can handle the rear end of a dump truck, it can handle the gear box of a small planer.

[David Peterson]

As always, really helpful info. Thanks, gentlemen. I know woodworking but have never been at all knowledgeable about motors and gears. It's terrible to admit that I've never even been inside an auto parts store. The time has come and the Castrol oil sounds like the ticket. And 900 HP, Larry?? Seriously? My Suzuki GSXR has 165hp and I can barely hang on if I give it a full blast. Sounds good to me!

[James Baker SD]

oops, I had it backwards. 90 weight gear oil is similar viscosity to 50 weight motor oil.

[Larry Edgerton]

If you are using your machine in the cold look to synthetics. They are thinner when cold but thicker when hot. I am a firm believer in synthetics in extreme conditions.