The Stovebolt Site Forums The Shop Area Driveline Steering Box Lubricant

I didn't want to hijack Roads Scholar's thread but this is related to his.

I have no problems with my steering. It doesn't jump around, there's no slack it it so I'm probably just poking a hornet's nest here. Anyway, I decided to look inside and it's packed with thick reddish brown grease.

Jon G suggest a 50/50 mix of Corn Head grease and 90w mineral oil in order for it to reach all areas of the gear itself.

I'm not removing the gear or rebuilding it. There's really no way to get all the thick grease out without disassembly.

What I was wondering is if it would make sense to add 90w mineral oil to the box and hope that the action of steering operation would mix the grease and oil together inside.

Or, should I leave well enough alone and forget about it?

That's a very good question, Otto. I can see where adding the Mineral oil could loosen up the grease that's in there but I'm also thinking about it creating a leak at the seal on the shaft. I "overhauled" my gear box by installing new bushings and a new seal and then filled with cornhead grease. My initial issue was play in the output shaft ( a lot ! ). If you end up going with the oil added, let us know how it turned out if you would.

Otto - I did what you are describing and it promptly ran out my pitman seal. Bright side, found and eliminated one more leak.

Once I replaced the seal, I did the 00 cotton picker grease.

Steering works, no leaks. I should probably just leave whatever kind of grease is in there alone. No need to open another can of worms.

Sounds like a plan. Don't like worms.....unless they are on a hook.

As I believe I mentioned before I am only speaking for the AD trucks...and I will admit I only have only spent 62 years fiddling with them. You folks can use corn head grease if you wish. Undiluted it is not correct and not what was meant for the AD steering gear and there is explanation of that by GM. If GM wanted you to use a thick grease, they would have not put a pour-in plug at the top...that much should be easily understood. And they would not have written this in the Shop Manual:

"The steering gear is filled at the factory with a special all-season gear lubricant. Seasonal change of this lubricant is unnecessary and the housing should not be drained. Whenever required, additions should be made using a lubricant which, at low temperatures is fluid and will not "channel" or cause "hard steering" and which will provide satisfactory lubrication under extreme summer conditions."

GM goes on to explain the pipe plug is positioned so as to prevent over-lubricating and that you should never use a pressure gun to force lubricant in the unit.

It is a design issue...the engineers had reasons for wanting it this way. If anybody in the audience is pouring corn head grease out of a grease tube into that hole, please take a video of it. I would really enjoy seeing it happen. Below are a couple of images of corn head grease. It is packaged in a grease gun tube for a reason.

The thing with thick grease is, it gets pushed out of the way and doesn't return. You could very well have a box full of grease and still have the gear teeth going metal on metal, and it's even worse if the gear box has a line of roller ball that run on the worm shaft.

If you pull the side cover off the gear box and carefully dig out what you can, you can make room for room gear oil. You then can reinstall the cover without changing the adjustments. At most you might have to cut a new gasket. Add some gear oil and work the steering back and forth. Your reddish brown grease is likely contaminated with rust, giving it the reddish brown color. At the lowest point in the gear box is the lower worm shaft bearing, most were barrel shaped and hard to come by, this is where water sets. I had to throw away two worm shafts before I found a good one due to crappy rusty grease.

I agree with you , Jon. I'm just wondering what I should do in my particular case. The grease inside my steering gear has been in it for more than 25 years at least.

I'm experiencing no problems with the steering but I got curious and removed the fill cap yesterday and discovered that the contents are more grease-like than oil-like.

I'm not going to remove the gear box so whatever is in there is probably going to stay in there.

Jon, would you recommend adding 90w mineral oil to the box? Would that accomplish anything?

I'll see if I can get a close up picture of the grease in the hole.

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