Keeping your Deuce… Mission Capable

Owning an historic military vehicle (HMV) such as a 2-1/2-ton “deuce” means different things to different people. Some folks love every minute of the time and effort that goes into doing a complete restoration. For others, the primary reason for owning a deuce is to drive it; and one doesn’t have to drive the Burma Road to enjoy the experience. It’s just as much fun for some people to drive their CCKW or M35 20 miles to a swap meet or show as it is for others who spend a week exploring the desert in their M35A1 or Studebaker US6.

I put many enjoyable miles on my first historic military vehicle, an M38, as well as on many other HMVs over the years. I learned a lot of lessons about keeping them “mission capable”. One of the most important lessons is that an HMV owner should be as self-sufficient as possible when it comes to on-board tools and spare parts. You should also possess — or learn — basic mechanical skills that include how to troubleshoot and repair your vehicle. It’s also essential to prepare a vehicle before embarking: the longer the journey, the more preparation. But, no matter where or how far you’re going you will be traveling in a vintage military vehicle, and even the most basic parts and components, such as water and fuel pumps, generators, starters, fan belts, tune-up items, and even head or tail lamp bulbs, won’t be found at most auto-mart stores or gas stations along the way. This scarcity of parts is offset by that fact that most common collector HMVs are simple machines by today’s standards. Many do not have power steering or power brakes, much less exotic electronics or on-board computers. What isn’t there can’t go wrong; and as long as a vehicle is basically sound, there isn’t a lot to break that can’t be replaced or repaired in the field by someone with a basic tool set, essential spare parts, and adequate mechanical skills.

You should adopt the “P Principle”: Proper Planning Prevents Poor Performance. When applied to HMVs, this translates to, every dollar and hour spent on preventive maintenance at home will often save 10 times that much in the field. The first thing to do when planning a mission is to thoroughly inspect and service your vehicle when you have plenty of time to do everything right, as well as obtain parts and spares.

For a deuce that is driven regularly, gear oil should be changed about every two years. This includes every component that uses gear oil, not only the transmission, transfer case, and differentials, but also the steering knuckles, steering box, and the winch gear case. Many oil additives found at auto-mart stores or touted on TV actually do improve gear oil to some degree. Synthetic oil is well worth the price if you plan to keep your deuce for many years. The time to replace leaking seals or gaskets is as soon as you discover the leaks. While it’s smart to carry extra gear oil in your vehicle, along with a pump to top-off a gearbox or differential, little leaks have a habit of suddenly becoming big ones at inconvenient times. Gear oil also thins out as it heats up, so what was only an annoying drip in your driveway may turn into a gusher after fifty miles on the highway.

You might consider adding locking hubs, or at least making a set of free-wheeling flanges for your deuce’s front axle. This will prevent useless wear on the front differential and driveline, improve fuel mileage, and lessen the chance of shimmy. Check and top-off the brake fluid in the master cylinder. If the fluid is more than two years old, or dirty or cloudy, replace it and bleed the system. Inspect all brake lines and hoses, the steel lines for rust or damaged spots, the rubber lines for cuts, cracks, or age deterioration. Make sure the hydrovac or air-pack unit is working properly. Check their connections for signs of looseness or leakage. Likewise, check any fittings or mounts on the axles or frame for looseness.

Wrapping flexible brake lines with friction tape can provide protection from flying gravel in the field as well as fending off sunlight damage. Products such as Armor-All work well in preserving rubber brake hoses and other rubber things, including the sidewalls of tires. However, it’s not a good idea to apply these products to the tire tread, especially on non-directional tires, because they may leave a slippery coating that could cause the tires to skid. Adjust the brake shoes, if necessary. Check the parking brake lining and mechanism, and adjust it so it holds. You may need to park your deuce on a slope with its engine running, so don’t rely on just being able to leave it in gear.

Check all the universal joints for looseness, and put a wrench on their mounting bolts to make sure they’re tight. Also check for looseness in differential input flanges and transmission and transfer case output flanges. It may be necessary to remove the drive shafts and tighten these flanges. Check the tightness and condition of engine, transmission and transfer case mounts. If a mount is broken, or its rubber is deteriorated so it might break, replace it. This is twice as important when carrying loads, pulling a trailer, or traveling off-road where engine mounts are subjected to heavy torque. Lube all fittings and make sure they all accept grease. If a fitting is damaged, replace it.

When was the last time the vehicle’s wheel bearings were packed? Front and rear? For a vehicle in daily use, wheel bearings should be cleaned and repacked about every two years or 12,000 miles. An often neglected item in HMV maintenance is the speedometer cable. This should be disassembled, cleaned, and lubricated about every two years in a regularly-driven vehicle, or if the speedometer needle begins to flutter and bounce. This also applies to mechanical tachometer drive cables.

Of course, change the engine oil and filter. Also change or service the fuel and air filters. On the engine, check all belts, hoses and flexible lines, such as the oil filter and pressure gauge lines, plus the oil supply line to the air compressor if your deuce has a compressor. If it does, check it for loose bearings, proper operation, and rattling or knocking sounds, which might indicate loose bearings. Likewise, check all components and accessories on the engine, such as the generator or alternator and water pump for loose, binding, or rough-running bearings, as well as making sure they’re securely mounted. On deuces such as the GMC M211, check the automatic transmission fluid. If it’s over two years old, looks dirty, or smells burned, drain and replace it. M-series deuces vehicles have fording systems whether or not a deep-water fording kit is installed. Check all connections, lines and hoses on these components because a leak can affect engine performance. Check that all engine accessories, such as starters, generators, pumps, and compressors, are mounted tightly. Check all the fuel lines the same way you inspected the brake lines and replace any questionable hoses. Many deuces have drain plugs on the bottom of their fuel tanks. After making sure the plug isn’t rusted in place, drain a little fuel to check for water. If the plug’s head is badly chewed up from pliers or Vise-Grips, replace it.

Examine the radiator for leaks. It would be wise to drain and flush the cooling system. This is something else that should be done about every two years. Make sure the radiator core is free of bugs, leaves, or other debris that block air flow and reduce cooling efficiency. Spraying the radiator with a garden hose from inside the engine compartment outward is a good way to clean it. However, using a high-pressure washer can damage a radiator. Take a look at the soft plugs in the engine block: if leaking or badly rusted, replace them. Make sure the thermostat is working, and always carry a spare, along with a gasket. A spare radiator and/or surge tank cap is a good idea. Check the cap’s gasket to be sure it’s in good condition so it hold pressure and doesn’t leak.

Check the torque of the engine’s cylinder head bolts. Also check the exhaust and intake manifold bolts for tightness, as well as the carburetor mounting bolts or studs. Inspect and lubricate throttle linkages, choke, and accelerator pedal mechanisms. Also check that the clutch release bearing isn’t getting noisy. Adjust the clutch pedal linkage for proper free play.

Make sure all the vehicle’s lights are working; and you should carry spare bulbs, including a head lamp. If the vehicle has WWII type tail lamps, invest in extra sealed units for them. If your vehicle has early style aluminum M-series lamps, it’s wise to remove the covers to be sure they can be removed, and to check that the bulbs aren’t corroded into their sockets. Spraying the interior of these lamps with flat white paint will boost their light output. Look over the vehicle’s wiring system for frayed or bare spots, and make sure that nothing is hanging loose or rubbing on anything.

Inspect the muffler and exhaust system for leaks or broken mounts, and check that the exhaust manifold-to-header-pipe bolts are tight on the engine. If, as is sometimes the case, these bolts are rusted solid, it would be smart to replace them now. High-temperature anti-seize compound will help keep new bolts from freezing up. Also check the exhaust-manifold-to-engine block gaskets for leaks. You might be able tolerate a slight exhaust leak when driving around town, but enduring such a leak of a long trip is neither safe nor pleasant. Don’t neglect driver and passenger comfort. Fix the seat cushions and repair the windows so they roll up and down. Take a good look at the tires for aging, cracks or excessive wear. Replace any questionable tires. Fix any slow leaks. They have a habit of becoming fast leaks on long trips. If the wheels are out of balance, bent, or if the vehicle shimmies, fix these problems.

Check the battery or batteries, and top off with distilled water. The average dependable life for most lead-acid automotive batteries is about three to five years. Keep in mind that even if your old battery seems to start the vehicle all right, it still may not have enough reserve capacity to keep cranking in a breakdown or out-of-fuel situation. Make sure all the battery cable connections are clean and tight, including the ground straps. Give the fan a shake — naturally with the engine off — to check for loose water pump bearings, and replace the pump if there seems to be excessive play, or if there is any leakage around the shaft. If the water pump has a lube fitting, lube it. If the fan is bent, replace it: a wobbling fan wears out water pump bearings. A fan with cracked blades or loose rivets is dangerous: replace it. Make sure the windshield wipers are working properly and the blades are fresh enough to clear the glass. If the windshield is cloudy with age or so pitted it’s hard to see though at night, consider replacing the glass.

You should always carry a good basic tool set whenever the vehicle leaves home. One of the most frustrating situations to be in is that of breaking down somewhere, knowing what’s wrong, but not having the tools to fix it. What tools to carry is a question that’s frequently asked by newcomers to the HMV hobby, so here is a list of tools I have found to be the most useful for most deuces:

#1. A set of combination wrenches, 5/16” to 13/16”.

#2. A 3/8” drive socket set, 3/8” to 13/16”, including a spark plug socket, and make sure the latter fits your water-proof plugs.

#4. A 3/8” ratchet wrench. #4. A 3/8” breaker-bar.

#5. A 3/8” socket extension 3-4 inches long.

#6. A 3/8” socket extension 6-8 inches long.

#7. A pair of slip joint pliers.

#8. A pair of Channel-lock type pliers.

#9. A pair of wire-cutters or lineman’s pliers.

#10. A pair of Vise-Grips.

#11. An 8-inch crescent wrench.

#12. A 10-12 inch Crescent wrench.

#13. A pipe wrench that opens farther than your largest Crescent wrench.

#14. Three or four good screw-drivers, including a Phillips-head. (A good “four-in-one” screwdriver is also handy.)

#15. A medium-sized ball-peen hammer.

#16. A feeler gauge for setting spark plugs and ignition points.

#17. An ignition points file (and/or some emery cloth).

#18. A pair of very small Channel-lock pliers for working on things like the distributor.

#19. A small chisel.

#20. A probe type electrical tester, one that’s right for your HMV’s voltage.

This is only a basic kit, but I’ve found that most repairs on most common U.S. HMVs can be accomplished with these tools. However, tools are like money; better too much than not enough. Some basic repair, emergency, and troubleshooting items that should always be carried aboard your deuce include a roll of electrical tape, duct tape, bailing wire, and 14- or 12-gauge electrical wire. About 6 feet of rubber fuel hose can come in handy, plus a few mini-clamps, though you can make emergency hose clamps from bailing wire or nylon cable ties (another handy multi-use item).

You should make up a pair of test leads from 14 gauge electrical wire about 6 feet long with alligator clips on each end, preferably of different colors. In addition to testing purposes, these can be used as emergency jumpers to bypass damaged wiring or to hot-wire an engine if necessary. Naturally, you should always carry a good set of battery jumper cables; and a fire extinguisher. An air compressor can come in handy. Inexpensive electric models will work on 24-volt systems if connected to the first battery. If your deuce has an air system, rig up a hose with an air chuck that’s long enough to reach all the tires. Carry a tire pressure gauge, a few extra valve cores and caps, and a valve core tool. Every vehicle should have at least one good quality flashlight aboard, along with an extra bulb. For a trip into the bush, extra batteries would be wise, and you would probably also have a lantern, camp light and maybe glow sticks. In this age of non-smokers, it’s easy to forget matches. Wind and waterproof types are best. A miner’s-light type flashlight that clamps on your head is handy when making repairs at night. A cheap little radio with extra batteries — even if your vehicle has a radio of its own — can help pass the time if you’re stranded somewhere or making repairs. Your vehicle should always have at least three road flares; and those DOT breakdown triangles are a good safety precaution if one has to work on their deuce along a freeway at night. Naturally, your deuce should have a proper jack and lug wrench. The same applies to spare gas and water cans, plus the standard-issue pioneer tools. Even if your deuce has a winch, you might find yourself in a situation where the engine won’t start and a creek is rising. A come-along can also be very useful. A fifty-foot length of wire rope with loops on each end will extend the reach of your come-along.

No HMV should travel far from home without basic tune-up parts aboard: points, condenser, rotor, cap, and ignition coil. For a long road trip, a few extra quarts of motor oil is wise, along with a can of brake fluid. An oil squirt can is also handy, along with a good stock of rags or paper towels. Many linen and uniform supply houses sell old rental coveralls cheaply, and these are another good item to have. If cold weather is possible, a heavy coat, blanket or sleeping bag, and even a little propane stove, can make an icy night by the roadside or an unexpected camp-out easier to endure, and could mean survival.

Other things that can make being stranded less of an ordeal are a few emergency rations, cans of soup, and instant coffee. Don’t forget toilet paper. For an extended journey, one might consider carrying a spare starter, generator, voltage-regulator and fuel pump. In other words, be prepared with anything that’s vital to starting the engine and keeping your vehicle mobile. While to some folks all these spare parts may seem like excessive expense, most of these items can be easily found, many through ads in this magazine, and/or online and purchased cheaply from the comfort of your home. But, they generally won’t be found in a small country town at 02:00. Neither are they likely to be cheap if you have to buy them wherever you find them or have to wait in a motel or camp spot while they’re being shipped to you.

Lastly, trust your instincts: it’s been proven over and over again that most people’s feelings or premonitions are more often right than wrong. I’ve been in many situations with vehicles, aircraft, or aboard a ship when I started having thoughts about something, and when I checked these things, I found something about to go wrong. So, if you’re driving along and find yourself thinking about the oil in the rear differential, then by all means stop and check it. With a little common sense, trust in your instincts, and through of preparation, your deuce will always be “mission-capable”.  

Love tech tips? Here are a few more articles to keep your HMV rolling.