Common Plymouth Duster, Valiant, Dart, Demon (etc.) Repairs

Engine and such

Most mechanics will replace the electronic ignition system at the slightest provocation, complaining bitterly about Chrysler electronics. This is a good indicator that you need a different mechanic. (The ballast resistor is a white piece of ceramic mounted to the firewall near the windshield wiper motor. There are two sets of wires going into it. This is some feedback we received:

Replacing the resistor was in fact easy, and was the problem. I'm wheeled again, for only $6.50. And if it weren't for your page, I'd have spent $50 for a tow, and maybe $50 labor on top of $6.50 parts... (from Alec Dinwoodie)

How do you know if you need a new ballast resistor? Your car won't start -- it will crank but as soon as you take the key off START and let it fall to RUN, it will stop.

Tuning your carburetor, of course, helps to cure idle problems, stalling, and emissions issues. This guide is written for relatively inexperienced people but has enough detail for those with some experience.

Unknown to most mechanics is the crankcase ventilation system and the crankcase inlet air cleaner, which should be cleaned once a year to avoid power loss and smoke. Some reported that the filter on their charcoal canister also had to be replaced fairly often.

Many Valiant owners have had to replace their speedometer cable; we have instructions (along with regreasing instructions for those whose cables aren't actually bad yet.)

A report on fixing electrical problems is at the end of this link. It includes a reference to Stan Martin's guide to alternator upgrades. Another site, Allpar, has a guide to upgrading cars with points to electronic ignition. For the many people who would prefer to keep their points, but do not know how to replace or gap them, we have a step by step guide here.

Wet weather stalling and idle problems can be fixed by using a high quality distributor cap and rotor (e.g. Blue Streak), distributor cap gasket (Standard PN AL-483G), silicone covered lifetime-warranty wires, and by putting weatherstrip foam over the ignition and voltage regular modules.

A common problem on slant six engines is exhaust manifold cracking. Wes Moeller suggested getting a Dutra Dual Exhasut Manifold. He casts new manifolds for the first three cylinders, then you modify a stock exhaust manifold by cutting off the front leg in front of the outlet and capping the opening. "This way you can have dual exhaust by having a muffler shop adding just one pipe, or just run a short pipe from the new front manifold into the existing pipe. Even though the exhaust manifold you have now is cracked, you still might be able to use it."

Dave Wordinger wrote that many fuel tanks are interchangeable: "According to the 1950-65 Chrysler Products Interchange Manual, the 1960 Valiant and 1961 Valiant and Lancer (non SW) use the same tank. The 1960 and 1961 station wagons use a different tank. All 1962s use a different tank, 1963s use another different tank, and 1964 and 1965 use the same tank, but different than all previous years."

Starting problems. Zachary Good wrote: "The choke on the Holley 1920 has a tendency to stick shut on startup. When car's been driven that day, don't give it any gas when you start it (floods the carb). Easy way to get car started is grab a screwdriver, pliers, a pen, something that won't have parts of dirt that will fall off. Stick it down the throat of the carb, keeping the choke open. Crank it with a decent amount of gas. Don't have someone looking into the carb, that backfiring could take off their eyebrows." (We've noticed that the Carter carbs sometimes do the same, with the same solution).

See the "instrument panel and controls" section for more failures to start.

Ben Deutschman of the Slant Six Club of New York/New Jersey wrote that slant six owners should be careful not to put on spark plugs with the "crush washer" (the loose metal washer at the end), but to take off the washer first, if they have a 1960-1974 engine. After 1974, the head was redesigned, the plug tubes were eliminated, and taper seat plugs were used.

Body (external) and suspension

The biggest problems with the Valiant were rust in the rear quarter panels due to a bad weld and water leaks through the dashboard (curable by taking the steps in this link). These led one columnist to comment that the Dart's combination of water leaks and unkillable drivetrains led thousands of people to drive around with wet feet.

Adjusting torsion bars: the sophisticated Valiant suspension sometimes needs adjustment. Randall Norton wrote: "The adjusting bolt [on the 1962] is near the middle of the lower control arm. Park the car on a level flat location. Jounce the car. Measure the distance from the bottom of the lower control arm to the floor. Measure the distance from the bottom of the steering knuckle, and check the difference. I don't have a 1963 manual, but for 1962 the difference should be 1 7/8 inches for standard suspension and 2 1/4 for heavy duty suspension. For 1964, the measurements are 1 3/4 and 2 1/8. Do the same thing on the other side, then go back to the first side and check the measurements again. Repeat as required. "

RKJGuy@aol.com says: $150 will buy a new weatherstripping kit for ragtop Valiant/Darts. The store is Andy Bernbaum Auto Parts, (614)244-1118. He also suggested Kanter for other parts; they are at (800) 526-1096 (US). Mention code W615-HMN56 and get a free (usually $3) catalog!!.

John Harris wrote that Valiants' "left handed [wheel bolt] threads on the one side only as I remember. It was a good theory and practice at the time because of wheel rotation the the nuts could come off. But most of the time some tire guy will wreck your studs and bolts anyway because they use impact wrenches that are not calibrated, just turned up to 'as tight as possible.' If this happens get them to replace the studs with standard right hand studs and new nuts, smile and call it a day."

Interior

Do you need shoulder belts or rear seat belts? Click here for some information.

If you find your windshield wipers only work when dry, try putting window foam tape over the wiper motor to keep the water out.

There are some details on heating and ventilation systems on this page.

Replacing the back seat. Wes Moeller wrote, "Try pushing down, then back, and then see if you can pull the front upwards. I usually put my weight on the seat with my knee while I'm pushing." Mitch wrote, "use the wooden end of a hammer handle and put it under the seat (there are two latches holding the seat down in the front) and the push the clamp back for each one. Seat should lift out after this."

Instrument panel and controls

Iver Krogh writes that gas gauge failure may actually be due to loss of the ground strap clipped between the gas level sending unit outlet and the steel fuel line on the frame.

Many of us have found that our automatic-equipped Valiants (and other cars!) would not start in Park sometimes, but needed to be switched over to Neutral. Bill Watson suggested two possibilities: the shifter linkage might be out of adjustment:

The linkage from your steering column attaches to an "arm" that sticks out from the tranny on the driver's side. Get under the car while someone moves the gearshift linkage. Place the car in park, loosen the bolts to the "arm", push the arm all the way in the direction park is engaged. Then push your gear level all the over the left - as far into "P" as it will go. Then tighten everything up.

The problem could also be the neutral safety switch, if it will not start at all:

As for finding the neutral safety switich, there will be a small wire attached to your starter solenoid that leads down under the floor toward the transmission. Follow this wire. You will find the neutral safety switch at the other end of it.

Bill Watson wrote this about replacing the ignition switch on a 1963 Valiant, but it probably works with other models:

If you look closely at the switch in the dash, there is a bezel that screws onto the ignition switch. You will find 4 small slots on the inner side of bezel, each a quarter of the way around. I usually use a screwdriver, carefully, to move the bezel in a counterclockwise direction. Once it moves, you can undo it by hand.

Once you get the bezel off, notice that the switch has a ridge along the bottom that fits into a corresponding slot in the dash. This keeps the switch stationary while you screw the bezel on/off. Once the switch is free, you can drop the switch under the dash and pull the wire connector free.

To install, place the wire connector onto the new switch, place the switch into the dash (note the ridge/slot) and screw the bezel back on. Use a screwdriver, or some similar object, to carefully tighten the bezel onto the switch when you get it as tight as you can by hand.