Saginaw Manual Steering Gear Tech Tip #1. Gear oil or Grease. Which to use?

In Uncategorized by MWS Staff

Gear Oil Or Grease. Pick Your Poison?

There is a great deal of mis-information regarding Saginaw Manual Steering gearboxes around the internet, and in print magazine and DIY manuals.  Many customers take lubrication standards from 1940-60s repair manuals or from internet forums.  While this info was applicable then it is no longer pertinent today.

We are frequently asked which do I use?  Gear oil or grease?

The short answer can be both.  Reality is often murky. GM (Saginaw Division of GM) compounded the problem by poor word choice. Many GM manuals state to use “lube”.  And then state gear oil and grease.  GM further states anything adhering to GM4673M standards is fine.

What does this exactly mean?

Gear oil is often the first thing that come to mind.  Will it work, yes.  Will it leak, probably!

Can you use grease?  Sure. GM originally called for self leveling grease from inception until the late 60s.  But GM discovered the grease they were using was acidic! This caused pitting, and premature failure of internal parts.  So GM went to a lubricant, but now even that is discontinued (GM Part No. 1051052)

What about Chassis Grease? It is “stiff” and is not designed for steering gear usage”Straight” from the container.

So what will work?

  1. CV axle grease–If you can find it in large enough quantities.  Normally found in those tiny packets with CV boots.  Almost exactly replicates the original performance standards without the acid problems.
  2. Many folks will use a chassis grease mixed with 90WT gear oil. Keep in mind they need to be mixed together and then installed into the gearbox. Do not simply just fill the box 1/2 way up with chassis lube and top it off with gear oil.  They may never mix together.

Our advice–Use LITHIUM GREASE. Lithium grease has all of the properties of mixing 90WT oil with a quality chassis grease without the hassle of mixing. Lithium Grease is available in tubes, or tubs at any auto parts store, unlike the CV axle grease. Plus it won’t leak like using straight 90WT oil, and it won’t cause problems with acid build up.

We use Phillips / Conoco Super Sta Grease #2 (Lithium Grease)