M37 Spark Plug wire Replacement
 

I am the new owner of an M37. In the spare parts provided to me are spark plug wire cables, several sets actually.
Could use advise from anyone who has replaced the wires before on these flat 6 engines. "tips and tricks" or "got yeahs".
I have the tech manuals for the truck, but experience always trumps the written word...lol! Old enough to realize that.

Any help is appreciated.

One of the biggest suggestions with the shielded wires is you do not have to torque them down to infinity. Hand tight and a slight turn with the wrench will suffice to make them waterproof. I always see a problem where guys torque them down, and when you go to remove them, the spark plug turns instead. Then you have to remove the wire at the distributor (pretty tight spot there) and remove the wire with the plug.

Speaking of the tight spot, we were issued with a crowfoot socket or the special wrench for those wires. If you pick up the special wrench, it will allow more than the required torque needed.

Plug Type
 

Did you go with any specific plug type for the replacement?

That is getting a little harder to source, as the manufacturers seem to have dropped most of them. This is based on you having the original shielded plugs, or has yours been converted over to civilian plugs and wires?

The military used to use Autolite AR5S and AR7S for cold and hot service. The hotter plug was also better if your worn engine was starting to foul.
Those later became autolite 2243 and 2245. Champion had XMJ14 and XMJ17 as equivalents. Those were recently changed to Champian 588 and 517 respectively.

Most are now out of production, and prices are starting an upwards creep to $25 a plug and more. So it behooves one to clean and gap the plugs, and if you have access to a tester, check their spark under load.

Watch out for some of the plugs unscrupulous ebay sellers try to flog as being for the M-series vehicles, such as the AR8S. They are for the generators, and have a different porcelain interface.

There are a few other part numbers out there, but the above will be the basics.

Plug Type
 

Much Appreciated :)

Does Champion XED14 cross over to anything known?

Not a common plug. Even if it looks similar to an M37 plug I think you’ll find the porcelain insulator comes too high in the barrel: preventing the insertion of the M37 spark cable.

Thanks Brian. I didn't open the package to see what they look like, but have seen other plugs with the features you mention. Do you know the application(s) for these XED14 plugs? A friend has several.

Where are you?

Wayne.

Those plugs you have are High Temperature Industrial Plugs but I have no idea what equipment they would be used in.

David

Had a quick look and the XED14 fits odd US military equipment like a cement mixer or a tank and pump unit. In the case of the cement mixer it uses a Teledyne continental mote. In the case of the tank and pumping unit, it uses a Wisconsin motor. I looked at all of the cross reference numbers, and one of them ring a bell as to used on SMP trucks, nor on the common generators.
The NSN for those plugs is 2920-00-293-5212. They are not a cheap plug, usually running close to $30 a plug.