Problem: Poor wiper operation
Symptoms: Slow wiper Action
Improper shut down
If you are experiencing any or all of these problems and have vacuum wipers on your Thunderbird the problem is probably the vacuum wiper motor.
These motors are quite simple and rely on a certain amount of grease for sealing the inner workings. Over the years this grease dries out and gets stiff thereby slowing down the motion and in many cases making them so stiff they won't hardly operate. All this can be: solved by cleaning the parts inside and applying new grease and sealing the unit back up.
To do this you must remove the unit from the car. To accomplish this you should follow the instructions in the shop manual (or fly by the seat of your pants if you have the experience). If you need a copy of the shop manual pages with this info call me, I will mail you a copy n.c.
Once the unit is out wash it off with some good solvent or preferably some spray brake or carb cleaner. Cleanliness is very important throughout this whole operation. Lay down some clean towelling to work on.
The screws used on this unit are of an elliptical type and I don't know who supplies a tool for them so you will have to make do with a small needle nose pliers and maybe a small regular pliers.
1) Remove the screws holding the cover on the switching mechanism located on top of the unit and remove the unit with all pieces. Lay them aside.
2) Remove the two screws holding the cover on the front of the motor. Inside you will find a spring loaded cam that switches the direction of the motor.
Remove the plastic cam and then the spring and plate assy. Lay them all aside.
3) Now remove the screws holding the top cover on the housing. When you are ready to remove the last screw hold the unit together as you remove it.
After removing the last screw carefully remove the cover watching that you do not lose any pieces of the gasket. You will also see that there is gasket material located in the small wells (recessed areas) where the ends of the shafts lay.
Remove all gasket pieces and carefully save them. When you reassemble this you will have to use all of the old gasket pieces over again. Remove the shaft and flap assy. Now - wipe all the grease off of everything and wash every piece very carefully using some of the carb or brake cleaner.
4) Before reassembling, liberally coat the complete inside of the housing and the top cover with silicone grease including all tht: gasket surfaces. Also coat the flap and shaft assy.
5) Install the gasket pieces in the shaft wells and sit the shaft and flap assy. in the housing.
6) Stick all the rest of the gasket pieces on the proper place on the housing case making surr: that they are dl there. There must be a total seal to the cover.
7) Install the cover and screw it tight.
8) Install the spring and plate into the area on the Front of te: housing hooking it on the tiny pin. Coat the small area at the top where the plastic cam sets with some silicone grease and also coat the plastic cam and instaII it.
Before installing the cover on the front, check the action of the cam by holding it lightly in place while rotating the motor shaft through its entire cycle. The small plastic cam should snap back and forth as the motor shaft nears each end of travel. If all is satisfactory, install the cover and screw it tight.
9) Apply graphite lube to the rubber block in, and the plastic slide for the top switching mechanism and also to the flat metal spring and install these items screwing the hold down cover on.
10) You can now test the unit before installing it up under the dash by hooking a vacuum hose to it from the engine and with the engine running, switch the unit on and it should oscillate fiom one direction to the other. Watch when you shut it off by the switch on the unit that it travels all the way to one
end of the stroke before quitting. This will ensure that it will "park" the wipers properly before shutting off.
Congratulations! You can now install it back in the car. You should also replace the hose to the unit at this time. You should have some nice smooth operating wipers. It would be a good idea to replace the wiper blades now so you can rest assured that this part of your car is completely taken care of for awhile.
John R. Draxler ph. 715-884-6546
back to Tech Tips