Is you carb sad? Why not a new one?

You need to keep your gears lubricated.


I hope it isn’t to oily for this subject but here goes anyway…

From EM 1110-2-1424 28 Feb 99:

Gear Lubrication
a. Lubricant characteristics. Gear lubricant must possess the following characteristics:
(1) General. The following characteristics are applicable to all gear lubricants. The lubrication
requirements for specific gears follow this general discussion:

(a) Viscosity. Good viscosity is essential to ensure cushioning and quiet operation. An oil viscosity that is too high will result in excess friction and degradation of oil properties associated with high oil operating temperature.In cold climates gear lubricants should flow easily at low temperature. Gear oils should have a minimum pour point of 5C (9F) lower than the lowest expected temperature. The pour point for mineral gear oil is typically -7C (20 F). When lower pour points are required, synthetic gear oils with pour points of -40 C (-40 F) may be necessary. The following equation from the ASM Handbook provides a method for verifying the required viscosity for a specific gear based on the operating velocity:


equation02= lubricant kinematic viscosity at 40EC (105EF) (cSt)
V = pitch line velocity (ft/min) given by :
V = 0.262nd
where n is the pinion speed in rev/min and d is the pitch diameter (inches).
(b) Film strength. Good film strength helps prevent metal contact and scoring between the gear teeth.
(c) Lubricity (oiliness). Lubricity is necessary to reduce friction.
(d) Adhesion. Helps prevent loss of lubrication due to throw-off associated with gravity or centrifugal force especially at high speeds.
(e) Gear speed. The now-superseded Industrial Gear Lubrication Standards, AGMA 250.04, used center distance as the primary criterion for gear lubricant selection. The new version of this standard, designated AGMA 9005-D94 Industrial Gear Lubrication, has adopted pitch line velocity as the primary selection criterion. As noted above, gear speed is a factor in the selection of proper oil viscosity. The pitch line velocity determines the contact time between gear teeth. High velocities are generally associated with light loads and very short contact times. For these applications, low-viscosity oils are usually adequate. In contrast, low speeds are associated with high loads and long contact times. These conditions require higher-viscosity oils. EP additives may be required if the loads are very high.

(f) Temperature. Ambient and operating temperatures also determine the selection of gear lubricants. Normal gear oil operating temperature ranges from 50 to 55 C (90 to 100 F) above. Oils operating at high temperature require good viscosity and high resistance to oxidation and foaming. Caution should be exercised whenever abnormally high temperatures are experienced. High operating temperatures are indicative of oils that are too viscous for the application, excess oil in the housing, or an overloaded condition. All of these conditions should be investigated to determine the cause and correct the condition. Oil for gears operating at low temperatures must be able to flow easily and provide adequate viscosity. Therefore these gear oils must possess high viscosity indices and low pour points.

Army Jill and the WW2 jeep.

Does all those numbers make your head hurt like mine? Simple truth? Use the right oil for your jeep engine…I use 10w30 to keep it simple.



So what is viscosity, anyway?

So what is viscosity, anyway?

As we saw in an earlier posting we need to be concerned about the viscosity of the lubes we employ in our WW2 jeeps (of course this is true in any vehicle). More from EM 1110-2-1424 28 Feb 99:


Effect of viscosity on flow of light and heavy oils.

Note–The spout in each container is of the same size, and each grade of oil has flowed for the same time. Graphic from TM 10-540, December 26, 1940

Viscosity. Technically, the viscosity of an oil is a measure of the oil’s resistance to shear. Viscosity is more commonly known as resistance to flow. If a lubricating oil is considered as a series of fluid layers superimposed on each other, the viscosity of the oil is a measure of the resistance to flow between the individual layers. A high viscosity implies a high resistance to flow while a low viscosity indicates a low resistance to flow. Viscosity varies inversely with temperature. Viscosity is also affected by pressure; higher pressure causes the viscosity to increase, and subsequently the load-carrying capacity of the oil also increases. This property enables use of thin oils to lubricate heavy machinery. The load-carrying capacity also increases as operating speed of the lubricated machinery is increased. Two methods for measuring viscosity are commonly employed: shear and time.

(1) Shear. When viscosity is determined by directly measuring shear stress and shear rate, it is
expressed in centipoise (cP) and is referred to as the absolute or dynamic viscosity. In the oil industry, it is more common to use kinematic viscosity, which is the absolute viscosity divided by the density of the oil being tested. Kinematic viscosity is expressed in centistokes (cSt). Viscosity in centistokes is conventionally given at two standard temperatures: 40 EC and 100 EC (104 EF and 212 EF ).

(2) Time. Another method used to determine oil viscosity measures the time required for an oil sample to flow through a standard orifice at a standard temperature. Viscosity is then expressed in SUS (Saybolt Universal Seconds). SUS viscosities are also conventionally given at two standard temperatures: 37 EC and 98 EC (100 EF and 210 EF). As previously noted, the units of viscosity can be expressed as centipoise (cP), centistokes (cST), or Saybolt Universal Seconds (SUS), depending on the actual test method used to measure the viscosity.

Say, you might be interested in Military Maintenance for MB/GPW Jeeps 1941-45 which is available from

How much does a jeep weigh?

How much does a jeep weigh?

Do you have the manuals? It’s in there. If you don’t have them yet then look at this – General Stats.


What does a jeep weight?

What does a jeep weight?

Net weight – 2,453 lbs.

Do yourself a favor. If you haven’t already purchased the WW2 jeep manuals–do it! Amazon has a reprint of the complete set of maintenance manuals for the jeep –The Complete WW2 Military Jeep Manual (Brookland Military Vehicles).

Come home safe! Check your steering.

Come home safe! Check your steering.

You might want to look at an article from my book, Military Maintenance for the MB/GPW Jeeps 1941-45. The article Jeep Steering Gear was originally from the WW2 Army Motors magazine. It basically suggests. “Before starting your adjustments on the ball thrust bearings on the cam you have to relieve the assembly of all load. Disconnect the steering gear connecting rod from the steering arm, loosen the instrument panel bracket and steering-gear frame bolts to allow the assembly to align itself.” And you really need the manuals, the cheapest way is $20 or less for the manuals on CDrom.

They have the added advantage that you aren’t mucking up your documentation on a single job. Just print and throw away when done.


Among other things, you need the WW2 jeep manuals to work on your Willys MB or Ford GPW.

You need to get the manuals if you don’t already have them. Buy ‘The Military Jeep Complete’ technical manual it includes TM 803, 1803A, 1803B. You might also consider the electronic version as well!  The electronic versions are a good bargain, print out the pages you need, take them to the garage, screw them up with grease and who cares ’cause you can print more. It is so very important to own these manuals because they tell you the basics of what you need to know. What grade oil to use? How do you service the brakes?
More advice can be found here.

A good jeep needs good maintenance.

This is a book that has been long in coming! I first started out creating this book in 1992. It was after reading an MVPA’s Army Motors article by Bryce Sunderlin concerning the availability of the wartime Army Motors magazine. When I obtained copies, it was only available in microfilm form. I wanted a copy that I could hold in my hands. Well with 1200 pages or more to choose from it would have been an exceedingly difficult task–so I concentrated on the World War Two jeep and articles that might be used to support it. My first attempt was very bad. The technology of the day was analog and either black or white, with no tonal qualities. Flash forward about ten years and then the technology was digital. So I had the microfilm converted to digital form on CDs. Next, I edited each page, sometimes spending up to three hours cleaning up the stray marks on the page. I ended up with a project that was approximately 440 megabytes. I couldn’t find a publisher that would take on the project. Even the print on demand outfit I normally use couldn’t handle the size. Finally, I found a publishing outfit that could handle the size. I hope you enjoy it. The book can be found at and Military Maintenance for MB/GPW Jeeps 1941-45.

Wanna know what to do with an axle washer? Well..listen up, I ain't going to repeat myself!

Wanna know what to do with an axle washer? Well..listen up, I ain’t going to repeat myself!

Wanna know what to do with an axle washer?

You should bend the washer to lock the nut in place.  I wouldn’t depend on goo to hold (though I did drive around for 20 years without bending or goo and never had a problem).  I now always bend the washer. But how?

The secret is from Al in New Zealand.  Pre-bend that sucker!  All you need is a little bit of a bend.  Then I use the standard Irwin screwdriver to bend into place.  Using the hub as a pivot (but I use the thick wall not the thin wall of the hub for the pivot…just in case).  After I started pre-bending, I didn’t have any problems setting and locking the nut.

So it really is easy to get those heavy washers to bend…you just have to know how!