Tech Q&A - Lubrication


Question: I understand that Ford originally recommended 600 weight oil for use is the Model A steering, transmission and differential. Are the oils you now buy which are described as 600 the same as originally supplied?

Answer: It is a mystery how or why the term "600W" became synonymous with Model A steering-transmission-differential lubrication. The only reference to "600" or "600W" I can find in Model A Ford literature is on page 377 of the Service Bulletin where they are discussing the seven tooth steering system. On page 375 of the Service Bulletins they recommend M-533 lubricant for the transmission and differential whereas on page 216 the recommend simply, "gear lubricant."

So far, we have been unable to locate information which defines the characteristics of what we commonly call 600W. Some 1919 Model T literature describes it as a "Steam Cylinder Oil." Elsewhere, the 600 is defined as the flash point of a specific steam cylinder oil. I have yet to buy "600 oil" where the container provides any information as to its contents.

I would prefer using a known viscosity oil rather than an oil about which I know nothing. Rather than buy an unknown, I would recommend a quality high pressure gear lubricant for the Model A steering-transmission-differential such as SAE 250 or SAE 140 in that order. SAE 80W-90 is a little thin for quiet shifting and you will probably hear more transmission and differential noise than with 250 or 140. Some companies are packaging an 85W-140 oil which is a little thin for our purpose. -- Lyle Meek, Technical Director


Question: At the moment I do not own (but plan to soon!!) A Model A. 600W oil is commonly used for lubricating the cylinders and valves, be they square or piston type, on steam locomotives and stationary engines. Texaco and Exxon are suppliers that come to mind as suppliers of this oil for most steam power nowadays. Hope this helps for those who want a heavier oil. -- Jim Shanks

I just have a quick question concerning the lubricant (600W) which the lubrication chart I have calls for: is there a replacement for this grease? -- Jason Wallis

Answer: 600W is an oil. It can be purchased from most Model A Parts Suppliers. For the Steering gear box I substitute STP. You can also add STP to the transmission. If you can not find 600W you can put 190 gear oil in the differential. 600W is the best for these applications. -- Les Andrews, Technical Director

Additional Information: Both Shell Oil and Texaco make lubricants that are very close to the original 600W product in both protection and viscosity - they REALLY slow down the transmission gears to make shifting as nice as an original car. The Shell product is called "Valvata" - The other is Texaco "Meropa 680".

Rick Black has been using Lubriplate SPO-288 for over 25 years after finding it difficult to locate 600W oil. Lubriplate is a gear oil especially formulated for rear axle and gear boxes of 1900-1930 vehicles. It has the same viscosity as 600W - pours slowly like honey. It's not sold in auto parts stores, but if you google "Lubriplate" and find their website, you can click on a link to locate a local distributor. His local chapter buys a 5 gallon bucket and splits it up into plastic one gallon jugs- enough for two servings each gallon.
Posted 06/19/18

One of Paul Shinn's YouTube videos on Model A lubrication and showed Mobilgear 600 XP460 as his choice for transmission and rear end oil.
Posted 05/26/23

You might be interested in the following posted by Dave Bockman on the Model A Message board -- - 1998:
There have been many comments on steering box, transmission and rear-end lubrication using a 600 viscosity oil. Here is one more I like very much. Texaco "Meropa 680" The viscosity is 680 and it meets AGMA 250.04 requirements for gear oil. I have conducted a few non-scientific tests with this product and others and have found it to be more viscous and has better "stick" than the product sold by Vintique INC. "gear lubricant" for $3.75 per quart. (It even looks better than their black stuff!!) It is available in 35 lb. pails (5 gallons). The product code is: 02342.


Question: I am working on a Model A that has not been started for some time and would like to check/change the oil in the differential and the transmission. The differential has two plugs - one on the bottom which I presume is for draining the existing oil, and one on the side which I presume is for adding new oil. My question is how much lubricant should I add? Enough to take it up to the second plug? If its more than that what is the best way to add it? I have the same basic question regarding the transmission. Once I have removed the cover of the gear box, how much lubricant should I add (i.e. how full should the gear box be)? Thanks for your help. -- J. W. Chambers

Answer: Add just enough fluid to the differential to bring the level to just below the opening. A good gauge is to insert your little finger to the first joint and it should have fluid on it when removed. The same goes for the transmission. Remove the filler plug on the side and fill with fluid until it comes up to just below the opening.

Capacities From the Ford Service Bulletins:

  Page 227:  
  Transmission 1 pint
  Rear Axle Car 1.5 pints
  7-tooth Steering 7.75 ounces
  Page 322:  
  2-tooth Steering 4.50 ounces


Question: I am changing the oil in a Model A. I don't know what type of oil was used before. I have seen your tech answer saying the an SAE 30 detergent oil is appropriate and desirable if the engine is clean. What about my situation. Can I replace the oil with detergent oil even if I don't know what was used before without cleaning out the oil pan and oil pump? What are the consequences? just smoky exhaust? And what about using a 20W-50 high detergent oil? Thanks. -- B. Cassels

Answer: Any detergent oil will work OK. If your engine has been using a non detergent oil for a long period of time, there will be deposit buildup around the rings, valves, and cylinders, etc.. Many times the wear in the engine parts is taken up by these oil deposits left in the engine. This is OK until you go to a detergent oil. After a couple of oil changes you will wind up with a real clean engine and the deposits that were taking up some of the wear space is now gone so expect to start using more oil. This will only be noticeable if the engine has a lot of miles on it and sufficient wear. I would think 20-50 would be OK. You should change every 500 miles. Maybe sooner the first time if you are not sure what was previously used. Hope it works for you. -- Les Andrews, Technical Director


Question: I've a couple of simple questions concerning my 1931 A roadster deluxe: Is it better to run the engine on leaded or unleaded gas? What happens if I use motor oil with detergent without cleaning anything before? -- Christian Affolter

Answer: Unleaded gas will not harm the Model A engine. Originally lead was added to gasoline as a lubricant to cool the exhaust valve seats. Over the many years of use the seats in the block have absorbed much of the lead deposits. Even with out lead additive, there is very little chance of burning the valves with this low compression engine. Some people have hardened valve seats installed when their engine is rebuilt. It is questionable weather this is necessary.

Adjust intake valves at .013 and exhaust valves at .015 inches and you will never burn a valve. I have three Model A's with standard block valve seats and have never had a problem with unleaded gas. In California we have had unleaded gas for a long time. If your engine has been using a non-detergent oil, you may have a build up of oil deposits and sludge in the engine. The detergent oil will in time clean all (or most) of the deposits and sludge from the engine and you will end up with a much cleaner engine. The detergent oil will suspend the deposits and sludge in the oil. When the oil is drained, the deposits and sludge are drained with the oil. A non-detergent oil works opposite. Sludge and other deposits are not suspended in the oil and settle to the bottom of the pan and collect around the rings. When the oil is drained there still remains oil sludge in the pan and around the rings.

The affect of using detergent oil in a dirty engine is it will give you a much cleaner engine after a couple of oil changes. It will also clean the deposits around the rings. If the engine has a lot of wear, the deposits are probably taking up a lot of the wear space. When the deposits are cleaned away with the detergent oil, you may start using or burning more oil because of the added clearances obtained from a cleaned engine. When using detergent oil , the oil should be changed every 500 miles. Since the Model A has no air or oil filters, the engine absorbs a lot of contaminates. I recommend using detergent oil and changing it every 500 miles which will give you a cleaner engine that will not wear the engine parts as quickly.


Question: I read in Popular Mechanics Q & A column about an "old-time" trick for lubricating valves by adding automatic transmission fluid (ATF)1 quart per tankful to the gasoline. The writer said that this absolutely cannot be done in modern cars with oxygen sensors and catalytic converters, but have you ever heard of this for the Model A engine? Or would it be better to keep using standard lead-substitute or a product such as "Marvel Mystery Oil" (Top Oil). My engine has not been upgraded with replacement hardened valve seats. Your Q & A column is very helpful and the first thing I read when I get my "Restorer"! -- Jim Wright

Answer: I have heard of this step and would not recommend trying it....stick with Mystery Oil, STP, Slick 50, Dura Lube or Prolong...these modern additives claim to keep the surface coated....I do use one of the above and am pleased with the results. -- Lyle Meek, Technical Director

Question: Where can I find the Model A lubrication chart? [Image]

Answer: The Model A Lubrication chart first appeared in the January 1928 Ford Service Bulletins on page 216. A digital copy of the lube chart is located here on the website. Another version which has photos of the components to be lubricated can be found here. Les Andrews version can be found here.

Most Model A suppliers can sell you a large color reproduction of the lubrication chart. Many Model A owners have one hanging up in their garages as a reminder of when and where to lubricate the chassis. --Rick Black, 2022


Question: I have a 1931 Model A standard coupe. I would like to know what type of oil I should use, 30 weight non-detergent or can I use a detergent oil? I live in the hot climate of Arizona. I have removed the oil pan and cleaned the oil pump and pan. I also removed the valve side plate and cleaned that area. The pistons and valves were checked with the head off. The engine seems to be in good condition and I plan on changing oil every 500 miles. -- Howard Little

Answer: If your engine is clean as you stated I would definitely use 30 weight Detergent oil. I have no preference as to brand. They are all far superior to 1930's oils. By using detergent oil and changing every 500 miles (as I do also) the grime is held in suspension and when draining the oil so goes the dirt and grime. Most contamination comes from no air filter on the carb.


Question: I am getting oil on my engine on the left side. It comes from the Oil fill tube. How can I stop this from messing up the engine compartment?

Answer: Make sure the oil filler tube has three baffles pointing down. This helps stop any oil from being slung out the filler pipe. Your problem is usually caused by too much blow by around the rings. You may need new rings or an engine overhaul. -- Les Andrews, Technical Director


Question: I have a 1930 four door sedan recently purchased. There is a very strong odor of oil entering the car after it heats up. Does it come from the oil breather? If so, is there a way to deflect the exhaust under the car so that it doesn't smell up the inside? Thank you.

Answer: Sounds like you have a very tired engine. What you are smelling is cylinder blow by caused by worn out rings and worn cylinders. The combustion chamber is leaking past the rings into the crankcase and being blown out the oil breather pipe. You can minimize the amount that gets into the inside of the car by putting a flexible breather pipe tube on the breather pipe to replace the cap. This is an accessory that has a flexible pipe that is about 24" long to route the blow by under the front floor boards. This may help some but will not eliminate the problem. An engine rebuild is the only solution. In the mean time use 40W oil and add some STP to thicken the oil around the rings and get a little better seal. This is not a fix, just a temporary band aid. -- Les Andrews, Technical Director

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Last Updated: 05/26/23