Headlight opening/closing inconsistency

[Michael J.]

I am curious about my headlights on my '67 coupe. They open very quickly and together. However, they close very slowly and the right side one lags, by a minute or more, the left side in closing. Any idea on the disease causing this?

[Jack H.]

Re: Headlight opening/closing inconsistency

When the motors check out A-OK on the bench and the car exhibits a LH vs. RH difference in HL bucket open or close time, it's usually the result of small but measurable side to side differences in rotational friction. I've seen guys tear their hair out trying to achieve lock-step synchronous operation with a few being sucessful via strategic shimming & mounting torque adjustment(s).

[Richard M.]

Re: Headlight opening/closing inconsistency

I had similar issues a while back on a 63. I opened the gearboxes on both motors, cleaned out the grease that turned to wax, re-lubricated and both then ran very close together both ways.

edit....Oh yea......Check the grounds on the motor and rad support too. When things heat up from current flow it may cause odd behavior. You may also want to check the ground screws on the motors to make sure they're the short length. Long screws here can cause a internal short to the field winding.

Rich

[Michael J.]

Re: Headlight opening/closing inconsistency

Thanks for the help.

[Harry S.]

Re: Headlight opening/closing inconsistency

Michael, the motors are unsophisticated, not complex, very simple and easy to rebuild. It is just labor intensive.

The only real problem is if the bronze bushing that the armature rides in fails. The you need to send it out for repair. Best I can tell there are some special tools and techniques in changing that bushing.

I had to have one of my bushings replaced. Since then the open/close timing difference for both is about a second.

[Stephen B.]

Re: Headlight opening/closing inconsistency

Michael
The headlites on C-2s have several things that typically cause them to operate inconsistantly or not at all.Lubrication or the lack of it is one factor. Rust around the bearing,shaft area.A stretched, mishapen potmetal gear. These gears get stretched at the end of their travel both on the up and down cycle.Lube on the bushings at either end of the motor.If your headlites are running slow or at different speeds it's time to take them apart clean and lube everything, replace the potmetal gears, and reassemble them.I have seldom had to replace anything but the gears. Don't let them intimidate you in any way. It's just simple disassembly ,clean, lube,replace the gear if needed , and reassemble. It has been my experiance that even after rebuilding them they won't run at the same speed.I am of the opinion that these should have been tied together with a shaft, or run by one common motor.Good Luck.
Stephen Barrett (21558)

[Ara G.]

Re: Headlight opening/closing inconsistency

Mike,
First the radiator and now the headlights? Your car and mine MUST be talking to eachother at night....Thanks for the advice on the radiator removal...It was helpful.
I have the opposite problem from you on the headlights. The driver's side goes up much slower than the passenger, but both go down at about the same speed. I have been told to warm the motor up with a heat gun and see if the lights work better. If it does, this is a sign that the grease has hardened and it needs removing and regreasing. I also checked my ground wire that helped some, but now that I have done more research into my problem I am not sure if it was a warm day that caused them to work better. I am tackling the issue this week as I am off from work and will let you know what, if anything, I discover. I plan on having them working wonderfully at Kissimmee come hell or high water. I will keep you posted. Good luck on your end. ARA

[Michael J.]

Re: Headlight opening/closing inconsistency

Mike,
First the radiator and now the headlights? Your car and mine MUST be talking to eachother at night....Thanks for the advice on the radiator removal...It was helpful.
I have the opposite problem from you on the headlights. The driver's side goes up much slower than the passenger, but both go down at about the same speed. I have been told to warm the motor up with a heat gun and see if the lights work better. If it does, this is a sign that the grease has hardened and it needs removing and regreasing. I also checked my ground wire that helped some, but now that I have done more research into my problem I am not sure if it was a warm day that caused them to work better. I am tackling the issue this week as I am off from work and will let you know what, if anything, I discover. I plan on having them working wonderfully at Kissimmee come hell or high water. I will keep you posted. Good luck on your end. ARA

Thanks Ara, this gives me some things to try too. Good luck on yours and I'll also report back if I find anything out.

[Domenic T.]

Re: Headlight opening/closing inconsistency

I had to clean,relube and inspect the gears after I did my drive motors and had a similar problem (years ago), the shimming helped but I found they were working better before I put them back on. I spent a lot of time on the alignment and remembered that a shop spectator decided to lean back and make a chair out of the light while it was loose. Also I bought some spare lights from the swap meet that may have been dropped.
I'm sure you will find it elsewhere but if not, the shaft alignment ( even with the balls) can be a factor.

DOM

[John K.]

Re: Headlight opening/closing inconsistency

Corvette restorer Vol 13 #3 Winter 1987 has a great article on rebuilding the headlight motors.