The other essential criterion for our steering gear lubricant is extreme pressure capability. The 1940 formula clearly states this aspect of the lubricant. I have seen recommendations at several collector car websites that state the opposite, but no explanation is given. I will provide you with the answer. The Pontiac worm and roller steering gear uses a bronze bushing to support the Pitman shaft; some extreme pressure additives are corrosive to bronze or brass and therefore incompatible. Our lubricant must feature a non-corrosive E.P. additive. Note that the formula has a Corrosion clause: “It shall not corrode any metal used for machine construction, either in the absence or presence of water.” Chlorine is a common E.P. additive that is un-acceptable due to its corrosive nature in the presence of water. Our lubricant must state that it is non-corrosive, and most of them do.
Note: This is also true for extreme pressure gear oils. Older automotive axles often used bronze or brass components; care must be taken when selecting gear oil for use in these cars. Some gear oils actually state they are non-corrosive to “yellow metals”.
Now that we know what we need, and why we need it; the task is find a suitable lubricant that is readily available. Fortunately NLGI grade 00 extreme pressure grease is commonly used in heavy duty truck applications for non-drive axle wheel bearings. These are synthetic or semi-synthetic blends that are far superior to what was available 50 years ago. Several refiners also offer quality E.P. greases in multiple NLGI grades. The most difficult problem is that of container size, especially the truck/trailer wheel bearing lubricants. The typical minimum size is a 5 gallon pail; obviously a truck repair shop is going to use large quantities of grease just to service the 6 non-drive hubs of a single tractor-trailer application. We only need one quart! My recommendation would be to take an empty 1 quart engine oil bottle to the parts department your local truck dealer or repair shop and ask to have it filled with 00 synthetic wheel bearing lube. I’m sure they have it priced by the pint or pound, as is typical for grease and gear oil.
The automotive E.P. grease is available in standard grease tubes, but 00 grade is not nearly as common as #1 or #2, as a special order item you would probably have to take a case lot of 12 tubes. By calling around, you may be able to find a distributor willing to sell you a partial case. A standard tube may contain from 10 to 14 fluid ounces, so you will need at least 2 tubes, if not 3 to completely refill the unit.
If your steering box is low on fluid, (it should be filled to the very top) and you only want to “top it off”, I recommend using non-synthetic, SAE 90 E.P. gear lubricant. The API rating is GL-5. Lubricant compatibility could be an issue; conventional mineral oil is the most likely to be compatible with the lube currently in your steering gear. If you know that your car has slight leakage from the Pitman shaft seal, take the time to find SAE 140 E.P. gear oil, it will be much more resistant to leaking.
I am hesitant to mix any modern synthetic gear lube with old lubricant already in the steering box. Gear oil is not formulated like engine oil; one important fact regarding new, improved engine oil is the stipulation that it can be used in place of previously approved oils without causing any engine damage. Gear oils, like commercial engine oil categories, must be compatible with the metallurgy of the components they are used in, so mixing gears oils can be problematic.
If you want to switch to any modern synthetic or semi-synthetic lubricant, you need to flush out as much of the old lube as absolutely possible. I like to use mineral spirits for flushing; it is readily available, inexpensive, and easy to dispose of by mixing with engine drain oil. I have a shop that takes my drain oil at no charge to burn in their waste-oil furnace; I even get my 2 gallon plastic jugs back.
You may find that once you have flushed and refilled your steering gear with modern lubricant, it develops some “play” in the steering wheel. The model year appropriate service manual contains specific instructions for the proper adjustment of the steering gear. The adjustment procedures must be followed exactly and performed in the correct sequence! These adjustments are sensitive and a slight change yields big results; so proceed carefully. The Pontiac steering gear is a well built unit and not prone to failure; but it is only natural after 50 or 60 years of service that it may need adjustment. If you take the time to service your steering gear and refill it with modern synthetic grease, it is unlikely it will ever have to be serviced again.
Opposite is the first page of the product data sheet for Unoba EP Grease. I included this because I wanted you to see the kind of information that you can find by searching oil company websites. Conoco/Phillips have some of the better looking pages; but the information contained is fairly representative of what you will find. There is a wealth of information provided; note the second bullet point under Applications which specifically calls out its use for water pumps on passenger cars.
The chemical formula is proprietary, so even the Material Safety Data Sheet (MSDS) will not reveal all of the ingredients. The application information, along with Features/Benefits will help you to decide if this grease is a good choice. You want to be sure the product description mentions rust and corrosion protection. This grease is also fortified with extreme pressure and anti-wear ingredients, which are not interchangeable terms or functions. Lubricants can have anti-wear additives but not meet extreme pressure requirements. Some companies also include packaging information, which this one does not. Since this product is intended for automotive as well as commercial uses, it is very likely to be available in standard grease gun tubes.
Specifications for Unoba EP Grease
This specification page is also representative of what you will find as part of a product data sheet (PDS). Some list less information, others even more. In my search for suitable steering gear lubricant, I was primarily interested in the NLGI grade, the useable temperature range and the Timken OK Load, ASTM D2509 number.
Note that several of the specification lines refer to ASTM tests. Formerly the American Society for Testing and Materials, ASTM International is an organization that develops testing standards for nearly every product in use worldwide. Test D2509 gives us a good indication of the ability of grease to withstand a load. The number shown is essentially pounds of force withstood. The specifications list the ASTM test used so we can make comparisons of products, knowing the tests are uniformly conducted and the results are meaningful.
This grease is available in 4 NLGI grades, which are determined by ASTM test D217. The next line lists the Thickener, some spec sheets use the term soap instead. Saponify is a chemical term meaning to convert a fat (oil) into soap by treating with an alkali. Basic grease is simply thickened oil.
The 1940 Pontiac formula used calcium soap, which is still in use. Lithium provides a more stable grease. The 1940 extreme pressure additive was Sulphur-saponifiable base; sulphur is also still in use, commonly in GL-5 rated E.P. gear oils.
The chart of recommended lubricants is on the next page. The PDS sheets are all available on the next page. I wanted to provide a variety of products; many of us have favorite brands we prefer to use, plus there is the possibility that you will have one or more local distributors in your area selling what you want.
Note: This is also true for extreme pressure gear oils. Older automotive axles often used bronze or brass components; care must be taken when selecting gear oil for use in these cars. Some gear oils actually state they are non-corrosive to “yellow metals”.
Now that we know what we need, and why we need it; the task is find a suitable lubricant that is readily available. Fortunately NLGI grade 00 extreme pressure grease is commonly used in heavy duty truck applications for non-drive axle wheel bearings. These are synthetic or semi-synthetic blends that are far superior to what was available 50 years ago. Several refiners also offer quality E.P. greases in multiple NLGI grades. The most difficult problem is that of container size, especially the truck/trailer wheel bearing lubricants. The typical minimum size is a 5 gallon pail; obviously a truck repair shop is going to use large quantities of grease just to service the 6 non-drive hubs of a single tractor-trailer application. We only need one quart! My recommendation would be to take an empty 1 quart engine oil bottle to the parts department your local truck dealer or repair shop and ask to have it filled with 00 synthetic wheel bearing lube. I’m sure they have it priced by the pint or pound, as is typical for grease and gear oil.
The automotive E.P. grease is available in standard grease tubes, but 00 grade is not nearly as common as #1 or #2, as a special order item you would probably have to take a case lot of 12 tubes. By calling around, you may be able to find a distributor willing to sell you a partial case. A standard tube may contain from 10 to 14 fluid ounces, so you will need at least 2 tubes, if not 3 to completely refill the unit.
If your steering box is low on fluid, (it should be filled to the very top) and you only want to “top it off”, I recommend using non-synthetic, SAE 90 E.P. gear lubricant. The API rating is GL-5. Lubricant compatibility could be an issue; conventional mineral oil is the most likely to be compatible with the lube currently in your steering gear. If you know that your car has slight leakage from the Pitman shaft seal, take the time to find SAE 140 E.P. gear oil, it will be much more resistant to leaking.
I am hesitant to mix any modern synthetic gear lube with old lubricant already in the steering box. Gear oil is not formulated like engine oil; one important fact regarding new, improved engine oil is the stipulation that it can be used in place of previously approved oils without causing any engine damage. Gear oils, like commercial engine oil categories, must be compatible with the metallurgy of the components they are used in, so mixing gears oils can be problematic.
If you want to switch to any modern synthetic or semi-synthetic lubricant, you need to flush out as much of the old lube as absolutely possible. I like to use mineral spirits for flushing; it is readily available, inexpensive, and easy to dispose of by mixing with engine drain oil. I have a shop that takes my drain oil at no charge to burn in their waste-oil furnace; I even get my 2 gallon plastic jugs back.
You may find that once you have flushed and refilled your steering gear with modern lubricant, it develops some “play” in the steering wheel. The model year appropriate service manual contains specific instructions for the proper adjustment of the steering gear. The adjustment procedures must be followed exactly and performed in the correct sequence! These adjustments are sensitive and a slight change yields big results; so proceed carefully. The Pontiac steering gear is a well built unit and not prone to failure; but it is only natural after 50 or 60 years of service that it may need adjustment. If you take the time to service your steering gear and refill it with modern synthetic grease, it is unlikely it will ever have to be serviced again.
Opposite is the first page of the product data sheet for Unoba EP Grease. I included this because I wanted you to see the kind of information that you can find by searching oil company websites. Conoco/Phillips have some of the better looking pages; but the information contained is fairly representative of what you will find. There is a wealth of information provided; note the second bullet point under Applications which specifically calls out its use for water pumps on passenger cars.
The chemical formula is proprietary, so even the Material Safety Data Sheet (MSDS) will not reveal all of the ingredients. The application information, along with Features/Benefits will help you to decide if this grease is a good choice. You want to be sure the product description mentions rust and corrosion protection. This grease is also fortified with extreme pressure and anti-wear ingredients, which are not interchangeable terms or functions. Lubricants can have anti-wear additives but not meet extreme pressure requirements. Some companies also include packaging information, which this one does not. Since this product is intended for automotive as well as commercial uses, it is very likely to be available in standard grease gun tubes.
Specifications for Unoba EP Grease
This specification page is also representative of what you will find as part of a product data sheet (PDS). Some list less information, others even more. In my search for suitable steering gear lubricant, I was primarily interested in the NLGI grade, the useable temperature range and the Timken OK Load, ASTM D2509 number.
Note that several of the specification lines refer to ASTM tests. Formerly the American Society for Testing and Materials, ASTM International is an organization that develops testing standards for nearly every product in use worldwide. Test D2509 gives us a good indication of the ability of grease to withstand a load. The number shown is essentially pounds of force withstood. The specifications list the ASTM test used so we can make comparisons of products, knowing the tests are uniformly conducted and the results are meaningful.
This grease is available in 4 NLGI grades, which are determined by ASTM test D217. The next line lists the Thickener, some spec sheets use the term soap instead. Saponify is a chemical term meaning to convert a fat (oil) into soap by treating with an alkali. Basic grease is simply thickened oil.
The 1940 Pontiac formula used calcium soap, which is still in use. Lithium provides a more stable grease. The 1940 extreme pressure additive was Sulphur-saponifiable base; sulphur is also still in use, commonly in GL-5 rated E.P. gear oils.
The chart of recommended lubricants is on the next page. The PDS sheets are all available on the next page. I wanted to provide a variety of products; many of us have favorite brands we prefer to use, plus there is the possibility that you will have one or more local distributors in your area selling what you want.
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