Headlamp motors siezed

[Joseph R.]

I have a 64 that has been in storage for 40 years. I have not powered it up but I want to rotate the headlights to the down position manually. I cannot turn the knurled knobs on the headlight motor in either direction with hand strength. Do these knurled knobs need to be loose to remove the motors from the headlamp panel pivot shaft? I know the knurled knobs also adjust drag or lash- do they loosen counter-clockwise on both RH and LH motor assemblies?

Any suggestion to free up the motors without damaging them? I have the Corvette shop manual. Thanks, Joe

[Timothy B.]

Re: Headlamp motors siezed

Joseph,

I would remove the motors and take them apart to clean and lube. The armature may be seized inside the bushings so if you power them up you are going to damage something.

[Dick W.]

Re: Headlamp motors siezed

I have a 64 that has been in storage for 40 years. I have not powered it up but I want to rotate the headlights to the down position manually. I cannot turn the knurled knobs on the headlight motor in either direction with hand strength. Do these knurled knobs need to be loose to remove the motors from the headlamp panel pivot shaft? I know the knurled knobs also adjust drag or lash- do they loosen counter-clockwise on both RH and LH motor assemblies?

Any suggestion to free up the motors without damaging them? I have the Corvette shop manual. Thanks, Joe

Knurled knobs do not adjust the drag. There is a screw with a locknut on the other end of the motor. I would remove the hairpin clip from the motor and remove it. It may or may not be the motor. The pivot balls on the headlamp housings have been know to seize.

[William L.]

Re: Headlamp motors siezed

Knurled knobs do not adjust the drag. There is a screw with a locknut on the other end of the motor. I would remove the hairpin clip from the motor and remove it. It may or may not be the motor. The pivot balls on the headlamp housings have been know to seize.

You armature probably looks like this.

[Bob R.]

Re: Headlamp motors siezed

If the motor hasn't been used in 40 years I would guess the grease looks like cement. I have found this to be the most common problem with the motors. Remove the motor from the car open it up clean out the old grease and inspect the aluminum drive gear. The gear may show wear, if so it only wears on half the gear so you can rotate it 180 degrees and install. Put fresh grease in it and you should be ready to go. There are only two fasteners holding the motor in place so it is easy to remove but working under the nose of the car is a pain so it may take a while to get it installed. I worked on it using a mirror which is very awkward.

[William L.]

Re: Headlamp motors siezed

If the motor hasn't been used in 40 years I would guess the grease looks like cement. I have found this to be the most common problem with the motors. Remove the motor from the car open it up clean out the old grease and inspect the aluminum drive gear. The gear may show wear, if so it only wears on half the gear so you can rotate it 180 degrees and install. Put fresh grease in it and you should be ready to go. There are only two fasteners holding the motor in place so it is easy to remove but working under the nose of the car is a pain so it may take a while to get it installed. I worked on it using a mirror which is very awkward.

If the drive gear wore out the armature will turn but not the gear. So most likely the armature is seize on the ball, not in the gear box but I could be wrong, wouldn't be the first time.

[Joseph R.]

Re: Headlamp motors siezed

Knurled knobs do not adjust the drag. There is a screw with a locknut on the other end of the motor. I would remove the hairpin clip from the motor and remove it. It may or may not be the motor. The pivot balls on the headlamp housings have been know to seize.

Thanks to all for suggestions. Dick, where the Corvette Shop Manual says at 12-8 " ... rotate knob six complete turns in opposite direction. NOTE: The above step is necessary to produce a no-load condition on the drive gear and permit separation of the motor from the pivot shaft." I'm reading the responses so far to say it isn't necessary to loosen the knurled knob in order to remove the headlamp motor from the pivot shaft, just the bracket, hairpin clip and electrical connectors. Is this right? Thanks, Joe

[Stephen L.]

Re: Headlamp motors siezed

Joseph, if you remove the screw holding the flat bracket and ground connection to the case and the wire "hairpin" clip, the motor will come right out. Also remove the flat bracket from the body for clearance and the wiring connector. In the photo you'll also see the "drag" adjustment screw and the knob for manual rotation....

[Joseph R.]

Re: Headlamp motors siezed

Stephen, thanks for the excellent pics. I have the bracket off the mounting grommet at the body (have not removed ground screw from motor housing on the motor end of the bracket yet) but there is absolutely zero movement of the motor assembly on the pivot shaft. I can see clearance for movement at the motor locating stud where the harpin clip is, both in rotation and along the pivot shaft, but my motor assembly won't wiggle at all. And I can't turn the knurled knob. I can't figure out what is holding the motor so securely. I don't want to break anything. Should I just pull harder? Joe

[Stephen L.]

Re: Headlamp motors siezed

Joseph, The shaft from the bucket just slides into the motor/gear housing. Things are probably seized due to corrosion. I'd just pull a little harder on the motor.....

[Joseph R.]

Re: Headlamp motors siezed

Joseph, The shaft from the bucket just slides into the motor/gear housing. Things are probably seized due to corrosion. I'd just pull a little harder on the motor.....

Stephen, I took your advice with success -- After rotating the locating stud a bit to break any corrosion there, I was able to force the motor assembly off the pivot arm by wiggling it aggresively. The Headlamp Panel is binding but I was able to close it by hand. The motor is still siezed but I can take it apart. The latching green plastic power connector is disintegrating unfortunately.


Thanks to all for your suggestions and help on this. Joe

[Stephen L.]

Re: Headlamp motors siezed

Joe, You should consider removing the bucket assy and cleaning up the rotating parts. Fixing the motor probably won't solve the issue of rotation and you might need to do the job twice.