Rear Seat Retaining Springs

These springs are the same for Ford GPW and Willys MB, aren’t they?

No they are not!!

Willys part number: A-2830
Ford GPW: 1161302

Ford did not design the Jeep and manufactured it under license to Willys, they simply copied the Willys drawings and their tooling department did not necessarily follow the Willys shape exactly.

The picture shows two springs clearly marked as to Ford and Willys.

The main difference is in the angle as marked.

To many restorers, this is not significant. But to those who don’t want to mix up parts, we hope this detail will assist.

Happy Jeep Restoring,
Darcy Miller

Radio Connection Box – Conduit

All radio connection boxes and hardware are the same aren’t they ?

No they are not!!

The picture shows two conduits clearly marked as to Ford and Willys.

The Willys conduit has a bend nearer to the end than the Ford conduit and the bends are significantly different in angles and therefore appearance.

All other hardware is the same, just the conduit is different.

I hope this snippet of information is of assistance to anyone restoring a late production Jeep fitted with the Radio Connection Box.

Happy Jeep restoring,
Darcy Miller

Fender Welt Kit

A question that arises regularly is about the Welting material that is used mainly between jeep mudguards and the cowl side panels.

Some restorers believe this Welting should cover the total length of the cowl side panel and encompass all three bolt holes that secure the Mudguard (Fender) to the cowl.

Here is a picture of an original mudguard (Fender) and you will see the Welting does not extend over all three holes.

The original material was a woven heavy cotton saturated in an asphalt bath and therefore can be a good electrical insulator on 6-volt vehicles although its original purpose was as an anti-squeak material where metal to metal contact occurs.

The reason for this Welting being short is to assist in connecting the mudguard electrically to the body proper.

Having restored over 50 WWII Jeeps we have seen this on many original Jeeps, sometimes the welting covers the top two (2) holes and on occasions, we have seen it covering the lower two (2) holes.

The M.V. Spares kit has instructions with the correct lengths, most other kits are incorrect.

Happy Jeep restoring,
Darcy Miller


Identifying Willy’s MB & Ford GPW Lug Nuts

The USA calls them Lug Nuts and other countries call them Wheel Nuts but to all countries, these are a small but critical component of your restoration.

Lug Nuts on the left side of a Jeep are Left-Hand threaded and on the right side are Right-Hand or Standard thread.

There is a significant difference between a Willys MB Lug Nut and a Ford GPW Lug Nut. The MB Lug Nuts are not stamped L or R whereas the GPW Lug Nuts are stamped L & R.

These pictures of original Lug Nuts show the Willys Left-Hand Nut is identified by a small cut in the outer hexagon whereas the Right-Hand Nut has no mark.

Note: the size of the nick seems to vary across the years and this is probably due to different cutting tools.

The GPW Nuts are indeed stamped L or R depending on the thread and have no nick in the outer hexagon.

You will notice on all Lug Nuts the large flat top, typical of the specific manufacturing process for WWII Lug Nuts in that they are all machined from hexagon bar stock.  For those interested in the older manufacturing times these machines were called Bar Auto Lathes, today CNC machining centres.

The material used in machining Lug Nuts is usually of a higher tensile strength than ordinary Mild Steel to allow the nuts to be tightened without distortion and used repeatedly over their expected lifetime.

Some cold headed Lug Nuts do appear as reproductions, their tensile strength is questionable and invariably are indistinct in the GPW L & R stamping and if the MB type are offered they are missing the important identifying nick on the Left-Hand Nuts.

Finally, the subject of finishes, early GPW Nuts have been found as Cadmium plated, we have even seen NOS samples with original tags attached and they were Cadmium plated. Later production was the black Parkerized finish.

Willys MB Nuts appear to always Parkerized finish.

We recommend using original nuts where ever possible and NOS or good used Lug Nuts do appear from time to time.

We will in the near future list a collection of NOS Lug Nuts on 

Happy and safe Jeep restoring,
Darcy Miller

Do your rain shields short out?

For a long time, WWII Jeep restorers have called these Rain Shields. Why is a mystery because they never get rained on. The WWII Jeep parts books, Willys, Ford and SNL-G-503 all call them “Cap – Spark Plug Insulator”.

Our customers invariably search for Rain Shields so we also refer to them as a Rain Shields but they are a Cap that goes over the spark plug insulator and not down on the cylinder head to protect from rain.

If you have experienced these shorting out the problem it is not a material problem, its an installation problem. 

Restorers invariably think the Cap must go down to and touch the cylinder head and this is totally wrong.

I am sure you have a copy of TM-9-803 but just in case you don’t here is a copy of one page which shows the rain shield goes as high as possible on the spark plug resistor before the lead is pushed onto the spark plug proper, there should be a considerable gap between the bottom lip of the shield and the cylinder head.

The high voltage in the actual spark plug circuit is likely to be around 20,000 / 30,000 volts and this can skirt across the surface of many non-conductive materials. There are more technical descriptions as to high voltages and its ability to travel over surfaces and jump gaps depending on sharp edges etc but all this is usually more than a Jeep restorer wants to know.

Maybe some can remember children getting car sick and Dad fitting a rubber strap to the car which touched the ground and static electricity was dissipated over the rubber strap and solved the problem, the rubber was not conductive.

So, if you experience this situation make sure the cap is fitted all the way up the copper part of the spark plug resistor and touches the Bakelite part of the insulator.

One final note, we have seen a few early NOS caps with small holes in the top that appear to fit the spark plug and not the insulator. We suspect these are first production and are very rare as we have only seen a couple in the past 40 years. Most NOS Caps we have seen are the larger top holes.

If you have any questions please email and we will do what we can to assist.

Happy restoring,
Darcy Miller

Fuel Filter Element

Why did we design a Modern element for our Filters?

The purpose of the filter element is to protect the carburettor and fuel pump by removing impurities from the fuel system to allow an engine to work at optimum efficiency.

Today we must contend with “Modern” fuels and these fuels are very different to the fuels of yesteryear; todays fuels can have additives like Ethanol and these additives are less stable today and have water absorbing properties which need to be dealt with by the filter.

Because your Carburettor or Fuel pump design is more than 80 years old you do not need to rely on old technology to protect them.

Everyone understands you can’t use old style diaphragms in your fuel pumps because modern fuels will quickly destroy them so just as it is necessary to change fuel pump parts it is important to use the most modern elements in your fuel filter.

The old-style brass element was designed at a time when modern high efficiency fabric elements were simply unheard of.

The M.V. Spares model MVK-1261 has a micron rating of 10 Micron (10 μm) at 99.8% efficiency. An original brass leaf element has a theoretical rating of approximately 120 microns. This means up to 12 times more impurities will pass through an original style element than an M.V. Spares MVK-1261 element.

Some aftermarket manufacturers have attempted to replicate the original Brass Elements.  The original design is prohibitively expensive and the desire to be price competitive with the modern elements has meant substandard construction where element efficiency is foregone to save on cost.

(Click for larger image)

Using the MVK-1261 you can expect an excellent service life and a corresponding extended service life of your other fuel system components.

Happy Jeep restoring,
Darcy Miller

Bond Strap #7 Willys A-7826 / GPW-18840

This strap runs from the Starter Motor Bracket Bolt to the Generator Mounting Bolt (rear) and then to the Engine Mount or as it is sometimes referred to as the Insulator.

Some restorers believe one end goes to the front engine plate on the righthand side of the engine, but this is not correct.

Original straps will be seen to have a 25/64” (10mm) diameter hole on one end and the other end an 11/32” (8.75mm) diameter hole.

The 25/64” (10mm) hole is to accept a 3/8” bolt.

The 11/32” (8.75mm) hole is to accept a 5/16” bolt.

Here is a picture of the correct strap on one of the most original untouched 1945 Willys MB’s one will ever find.   The #7 strap is still installed and attached to the front engine mount attaching bolt as it came from the factory.

If you need further information, please email darcy@mvspares and we will do what we can to assist.

Happy restoring,
Darcy Miller

Willys MB / Ford GPW Front Floor Drains

The front floors on the WWII Jeeps have a drain fitting on the left and right and these are threaded ¼ NPT to accept plugs.

The correct plugs are ¼ NPT slotted, early were brass and later steel and often Cadmium Plated.

Ref: Willys TM-10-1186 – Change No1 July 1, 1943.

The GPW part number is FM-358019-S

This is the correct slotted plug. Square headed plugs are not correct.


Below is a picture of an original floor with the correct plug fitted.


The plugs were installed as shown from the top down using the screw driver in the Jeep Tool kit. This allowed for the plugs to be installed without leaving the vehicle.

Do not install the plugs from underneath the vehicle as they can be dropped and easily lost.

Original Jeep publications call for the plugs to be stored in the glove box although where the Slat Grille Jeeps without Glove Box had them stored is unknown.

Here are links to the plugs and sockets:
M.V. Spares
Midwest Military

M.V. Spares has been manufacturing parts for WWII Jeeps for more than 40 years as well as having restored over 50 Willys MB and Ford GPW Jeeps. Experience we are pleased to pass on to our customers.

Happy restoring,
Darcy Miller

Trailer Wiring Kits – Bantam BRT & Willys MBT

You will no doubt be aware of the difference between the Bantam and Willys Trailer kits where the original Bantam kit external braiding was black in a coarse cotton with a pattern peculiar to the BRT and the Willys kits were taped in the same manner as the Jeep wiring kits.

We have now reproduced the original style cotton braiding to correctly replicate the complete Bantam BRT braided kits, no other manufacturer has gone to this trouble.

Happy restoring,
Darcy Miller

Wiring Kit – Part A

There are a number of things to be considered when deciding which manufacturer of WWII Jeep wiring kits you should choose for your restoration.

The first and most important consideration is the individual wire used in the harness.

In the 1940’s the wire was multi strand wire that was coated with a rubber insulation compound and then a further cotton braid applied over the rubber as a protection for the insulation. However, being natural rubber, it was somewhat fragile and easily damaged.

This process was initially seen in applications such as household appliance cords, fans, desk lights, etc, as well as the actual wire run in conduits to distribute electricity throughout homes and industrial buildings.

It followed that the same type of wire was soon being used in the Automotive field. With the different requirements of individual wires in vehicles, certain color codes developed with varied tracings to assist with making connections and troubleshooting.

One very important aspect of the cotton braiding for Automotive applications is that it was lacquer coated. This is critical because the specially formulated lacquer coating (which is not unlike a ladies nail polish) protects the wire from the oils and grease found particularly in engine bays. Equally as important the lacquer coating penetrates the surface of the insulation material, thus binding the cotton to the insulation and permanently prevents the cotton braid from separating from the base wire.

Application of the lacquer coating is done in specially designed machines and between 6 – 12 coats are applied with each coat dried before application of the subsequent coat.

Modern wire is no longer rubber coated but it coated with a Polyvinyl chloride or PVC insulation which has too many excellent properties to list here.

When you look at a correctly coated cotton braided modern M.V. Spares wiring kit the lacquer coating can be seen. Unfortunately there are producers in China and India who make similar material but they do not lacquer coat the wire. Kits made from this cheap material have a limited life and M.V. Spares does not use these suppliers.

All wire used by M.V. Spares is manufactured in the USA to the highest standards and we recently set up a facility in the USA to specifically manufacture our wiring kits.

We are proud to say our kits are “Made in USA”

We hope you find this article interesting and will soon publish “Part-B” covering terminals, taping, asphalt loom used on our kits.


Happy restoring,
Darcy Miller