I checked some threads with no luck.
i got a 1987 FB
Repaired bushings in both motors. the motors worked great until the bushings broke simultaneously in both motors
Right works great\
Left will go up, go down, but then wont go back up unless, i go turn the **** one time, hit the switch again then they go back up. It feels like the motor is torquing it self stuck

I was also wondering if there is a blow up pic of these motors avail.

Maybe i put it back to together wrong

 

Bump

 

You may need to open up the motor again. The "sticky" motor is on the side that you had to remove the motor from the actuator housing. What is hapening is the small bearing on the end of the wormdrive of the motor shaft is either missing or is not being supported by the small stub-shaft that is on the bottom of the actuator housing. This is allowing the worndrive of the motor to climb the OD of the plastic gear casuing it to be out of alignment and jamb. The small ball bearing must be supported on both sides (captured between the cup on the end of the wormdrive and the cup on the end of the stub-shaft).

If you are certain that the bearing is still in place, then you can just turn the upper **** to free up the motor shaft, then use a flat-blade screwdriver to hold the stub shaft in place while you loosen the locknut. Now turn in the stub-shaft until you start to feel some resistance. Tighten the locknut.

Lon

 

what exactly is the worm drive

 

That is the type of thread on the driveshaft of the motor. The wormdrive of the motor shaft turns the threaded outside diameter of the gear. To take this further to the end of how it works; inside the gear is a triangular-shaped cavity. Within that cavity were 3 cylindrical shaped pieces (often called pucks, bushings, inserts, etc) made of a hard gel material similar to a glue stick. Those inserts fill the gap between the gear and a 3-lobe cast hub that is staked onto the shaft that raises and lowers the headlight bucket. The older 3-wire headlight motors had an internal limit switch that turned off the motor at the end of either the up or down cycle. These 2-wire motors that were used for the 1987-92 model years do not have a limit switch. Instead the motor is turned on by the headlight switch. Power then goes thru the headlight control module, then out to each of the headlight motors. There is a circuit inside the headlight control module that senses the spike in current when the headlight bucket hits the physical stop in either the up or down position. When the headlight control module senses that spike in current it shuts off the motor. With age and the multiple times that the headlight doors are cycled up and down, the OEM hard gel inserts develope cracks, then continue to break until you get chunks, then just powder. At that point the headlight motors start acting strange. They may cycle the headlight bucket up or down, but because the inserts are in such bad shape the motor will continue to spin after the up or down cycle. Fortunately there is a secondary timed circuit inside the headlight control module that will shut off the headlight motors after roughly 6 seconds. Were it not for that secondary timed circuit you'd come out to your car and find the battery dead because the motors never shut off.

The OEM hard gel inserts were the weak-link in the system. Replace them with new Delrin bushings and the problem is solved. The next failure mode will be either the gear breaking or stripping or the 3-lobe hub stripping and slipping on the shaft.

Lon

 

WOW took me a while to get back online but thanks for the detailed information Lon. i will get back on this project this week and let everyone know how things went.

Thanks Again Lon.

 

Things went good and it is all fixed and working great

 

I'm glad to help.

Lon