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From the 1960s to 1994, many rear-wheel-drive Dodge, Plymouth, and Chrysler cars and trucks used a windshield wiper linkage between the motor and the wiper arms which relied on small plastic couplers. These couplers had a finite lifespan — which appears to be less than 34 years on average. Here are some repair tips; while these are written for the Valiant (Dart and Duster), other models are probably similar or identical.
Richard Henley wrote:
The parts are available through any Dodge dealer, as they were used on most every domestic Mopar from the late 1960s clear up to 1994. [Rudy Grein wrote: part number 3799089, 2008 retail price $5.20].
First, make sure there is a dollop of white lithium grease in the cup on the coupler before you put it together. The Mopar part should already have it already in place, aftermarket generally does not.
Do this on a warm day where you can set the plastic parts in the sunshine, or in a heated garage. Don't try this on a cold day, as you will just break your new couplers.
It was a pain on my 1975 Duster and 1968 Valiant Signet. You don't need to remove any of the parts from the car except the linkages, a real pain because you have to remove the glove box liner, defroster hoses, and possibly a few other things that may be in your way in order to get to the linkages themselves.
With the wiper motor and the wiper transmissions in place, first thing is to remove only the linkages, if one coupler has broken you will probably want to replace all of them anyway. With two pairs of needle nose pliers, push the couplers into the holes in the end of the linkages.
Next feed the linkages back under the dash, and squeeze them (very carefully) back onto the balls on the wiper motor arm and transmission arms with a pair of Vise Grips or Channel Lock pliers.
If you have already put the couplers together, you might want to get some new ones as they don't come apart for reuse very successfully.
Scott S. wrote:
What would probably be easiest for you to do is to take the whole armature out from under the dash. You have to do it from inside the car while sitting on the floor under the steering wheel - a pain but that's the easiest way to get to it.
The motor is held in by four bolts, two of which also hold electrical connections — one power, one ground. You will need deep-dish half-in sockets to remove the motor. (The motor has to be removed if you have air conditioning; you will then make the final reconnection at the motor, putting the arm back on.)
The armature is held onto the motor by a screw. You then need to remove the wiper arms themselves from the piece of the armature that they mount to.
Once you do this, you can just pull the armature down from under the dash. There are bolts that hold the pivots for the wipers on there that you need to remove. You'll most likely want to replace the seals that go around the pivots that the wiper blades themselves mount to, also. These seals are sold by Schumaker and others.
Once you get the whole armature out of the car, it's very easy to use pliers to clamp the armature together and to get the plastic pivots to snap into place. With the armature under the dash, you really don't have enough clearance to do this - it's easier to take the whole thing out of the car and do it.
When you put it all back in, you just bolt everything up and you're done.
The hard part is laying on the floor and over the transmission hump, and working in an area of tight clearance to do this.
Scott mentioned, once or twice, that taking the wiper linkage out of a non-air-conditioned car is much, much easier, and does not require the glove box or radio to be taken out. The main issue is the combination evaporator-heater core-duct housing, a large plastic piece which is difficult (and probably not desirable) to remove.
If you were curious, this is Scott S. in a rather more revealing photo from the 2008 New Brunswick meet.
Thanks, Scott S., for doing most of the work on fixing the windshield wiper linkages. To the rest of you, here are the tricks we learned:
1) If you have air conditioning, remove the glove compartment box (and, if you can, the door); the ash tray and its housing; and your radio first. Otherwise, you won't be able to do much.
2) The wiper arms have to come off and they have a funny latch mechanism which must be disengaged while the arms are pulled up; then they lift right off.
When you put the wiper arms back on, they have to be dropped back down onto the glass... you may not get the positioning right the first few times.
3) Get at least four of the plastic links and replace them all.
4) A kit used to be available from Schumaker with grease fittings (these can be essential if the reason for the link failure is a high-friction pivot), new water seals, and instructions. A kit might be available from other vendors. These kits are essential to leakproofing the Valiant.
5) You will need a light down there. I suggest a compact fluorescent in a standard housing because you won’t burn yourself on it. You may, however, still poke your eyes out on the bolts that hold the a/c vents on, so WEAR GOGGLES. That will also protect you from a trip to the hospital with fiberglass particles in your eyes.
6) Use duct tape to get all the sound insulation firmly mounted where it belongs, or tear it out, because otherwise your wiper links will rub up against it and tear it apart.
7) Once the glove compartment is out, you can gently disengage the lower end of the defroster hose, which will be helpful.
8) Once the linkages are back in, make sure they are not rubbing any wires with those razor-sharp edges.
9) We did a thorough job of taping back the insulation afterwards. Some of the pieces can be very difficult to apply. Again, you must wear eye protection while dealing with it, as much of it will be falling back down onto you. Even the greats have been known to go to the hospital from “fiberglass eye.”
10) The ideal is to tear out the existing insulation entirely and install a new kit you’ve already purchased for around $20 - $40. Prices for these seem to vary.
John Thompson added, “The arm from the wiper motor broke free at the driver side wiper. At first I couldn't get the pieces to fit. Then I ran the wiper motor, and turned the keyswitch off halfway through the stroke so it was in a more accessible position. I pressed the coupling into place using a 2 1/2 inch c-clamp along with a large diameter socket wrench piece, so I wouldn't damage the plastic. Then I used the same setup to press the wiper part into the coupling. I did it under the dash. I had to lie upside down and duct tape an inspection mirror and a small maglight in place to see what I was doing. I also got a mouthful of insulation I knocked free.” But he didn't mention whether he had a/c.
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