Look for an open port on the wiper motor that sticks out enough to attach a piece of vacuum hose. Rig up a Coke bottle of Diesel fuel with a short pierce of hose in it, turn on the wipers, and let the vacuum draw the liquid through the motor. It will clean and lubricate the wiper motor without ever having to remove it from the vehicle, and the Diesel will go through the intake manifold and clean and lubricate the valve guides before being burned in the combustion chamber. We used to use 6-ounce cans of Aviex tune up oil to rehab wiper motors that way, but Diesel will do the same job.
Jerry
This is a great example of the value of these forums. Old timer tricks like this are priceless.