steering gear lube...one more time please

[Robert B.]

I did a search and read all the good info about the correct steering gear lube to use in my '73. I searched the GM electronic parts manual starting with p/n 1051052 and as others have mentioned it is obsolete and dead ends before any reference is made to 12377985. The p/n recommended by people here is 12377985. The tube identifies the contents as "chassis grease" and the '73 repair manual states not to use EP chassis grease in the gear box. Realizing that 1973 was a long time ago perhaps the grease is formulated differently and higher tech.

In any event what was in my steering box was black and very viscous like about 80W or 90W oil and not very much of it. Could that have been original? I used a big big seringe my wife (the nurse) brought home and injected 120cc (4 oz) of the grease into the bolt hole in the top of the gear. I used the upper bolt hole but I would recomment using the lower bolt hole to fill. You can't overfill and have to leave room for airation and expansion. The repair manual states not to overfill but doesn't say anything about what "full" is.

Anyway here's a pic of what I did that might help others. Following the fill I adjusted the worm gear and end bearing clearances and rebuilt my steering column and things feel really good now. My steering use to be very sloppy, clunky and noisy.

[Joe L.]

Re: steering gear lube...one more time please

I did a search and read all the good info about the correct steering gear lube to use in my '73. I searched the GM electronic parts manual starting with p/n 1051052 and as others have mentioned it is obsolete and dead ends before any reference is made to 12377985. The p/n recommended by people here is 12377985. The tube identifies the contents as "chassis grease" and the '73 repair manual states not to use EP chassis grease in the gear box. Realizing that 1973 was a long time ago perhaps the grease is formulated differently and higher tech.

In any event what was in my steering box was black and very viscous like about 80W or 90W oil and not very much of it. Could that have been original? I used a big big seringe my wife (the nurse) brought home and injected 120cc (4 oz) of the grease into the bolt hole in the top of the gear. I used the upper bolt hole but I would recomment using the lower bolt hole to fill. You can't overfill and have to leave room for airation and expansion. The repair manual states not to overfill but doesn't say anything about what "full" is.

Anyway here's a pic of what I did that might help others. Following the fill I adjusted the worm gear and end bearing clearances and rebuilt my steering column and things feel really good now. My steering use to be very sloppy, clunky and noisy.

Robert-----


GM #1051052 was a very common GM manual steering gear lubricant of about 90 wt viscosity used from the 50's until August, 1978 when it was replaced by GM #1052182. That product was available until a few years ago when it was discontinued. There may be a supercessive part number but I can't find it. No matter, though, because while this lubricant was widely used in GM steering gear applications, it was NOT used for any 63-82 Corvette.

1963-82 Corvettes used lubricant GM #1052084. This is a much higher viscosity lubricant of about 160 wt. It was discontinued from SERVICE in May, 1997 and replaced by GM #12377985 which is what you have. That is the correct lubricant.

If you found what appears to be 90 wt-like lubricant in the steering gear box, then I'd say that someone previously installed the wrong lubricant. Believe me, it's always seemed to me that everyone and his brother thinks that the common, lighter weight steering gear lube (i.e. the 1051052 or 1052182) is what's used in Corvettes "because all other Chevy's use it". It's NOT the correct lube for a Corvette, though.

If I were you, I'd remove the steering gear box, clean it up internally as necessary and install the correct lube. By the way, you don't need to struggle with a syringe for topping off the steering box. You put the grease cartridge in a grease gun and inject it into the bolt hole thusly.

Also, I note that the color of the GM #12377985 seems to have changed. The product that I've seen and used is a much darker color.

[Gary R.]

Re: steering gear lube...one more time please

You're better off removing the box as Joe said to properly adjust and lube it. I do a lot of these and many times I see where grease was added through the holes but went no where as the old, dried out grease is an effective dam. I posted pictures of this on my rebuild threads on the other forums.
Chances are the box needs attention as well. Many have been "adjusted" in their life and are way out or worn out. Corvettes get a bad rap for steering boxes and brakes, in truth they are poorly serviced many times creating the myth they are not good. Properly setup and rebuild, there is no need for aftermarket "upgrades"

Good luck

[Jim S.]

Re: steering gear lube...one more time please

Saginaw engineering always recommended, "a good grade of lithium based chassis grease" for their manual gears. There are probably better greases available today (30 years later) but I am sure that chassis grease will work.

Jim

[Duke W.]

Re: steering gear lube...one more time please

Due to the Corvette's tight packaging and high engine setback the steering gear is right next to the exhaust manifold, so it gets "cooked" a lot more than on other model lines.

For this reason I recommend a full synthetic base NGLI #2 general purpose/wheel bearing grease with a drop point of at least 450 degrees F - the same thing you would use in the rear (and front) wheel bearings.

A synthetic oil base is more resistant to oxidation, so it's the best choice for these "lubed for life" applications. I'm not terribly concerned about the soap base, but most are probaby lithium.

Duke

[Joe C.]

Re: steering gear lube...one more time please

Use any high temp chassis grease for the reasons mentioned above. Steering gearboxes were originally filled with ordinary chassis grease.

[Gary R.]

Re: steering gear lube...one more time please

I use the new Mobil 1 formulation in the boxes but no longer in the bearings. I use Timken bearing grease in the bearings now. The new mobil grease is thicker then the older formulation and I found it really tightened up the bearings when I set them to 0015 endplay. Using the old mobil or the Timken at the same spec they were fine.

[Joe L.]

Re: steering gear lube...one more time please

All-----


GM specifies that the steering gear lubricant used for Corvettes must meet GM spec 4673M. They also caution that chassis lube meeting GM spec 6031M should NOT be used.

We know that the old GM #1052084 met the GM #4673M spec. Presumably, since GM officially replaced the 1052084 with the 12377985 the latter should meet the GM #4673M spec. As far as what other greases meet the GM #4673M spec, I have no idea. That's why I recommend the 12377985.