Pop up light problem

[puppyfang]

Have a 1975 and the front lights all work, however one light comes up nice and smooth and the other comes up with a real jerk...you can feel and hear it...what do I have to do to try an adjust this so it comes up smoother like the other one....thanks for any suggestions...

 

[KOPBET]

Have you looked at the springs?

 

[Vettehead Mikey]

They're supposed to come up with a real 'jerk' and lock into position. It's your 'smooth' side that needs work. Probably a leak.

 

[puppyfang]

interesting...never thought of it that way...will check both for leaks or the spring...thanks

 

[bmotojoe]

With your engine off you should be able to get your finger tips under the front of the headlight assembly and lift the headlight assembly up and crawl under the front of the car and move the assembly up and down to look where it may be hanging up. If you lift the assembly into the full upright position the headlight assembly will lock up and you will have to start the engine so it will return closed. There is a pin that has a flat washer and a cotter pin going through the link and upper bracket that comes real close to one of the springs right before the headlamp assembly is in the full open position, if the head of the pin is worn a little letting the pin to extend longer then it should the flat washer or cotter pin could snag the spring. There are adjusting stop bolts that come in contact with one side of the headlight support bracket and they do make a metal to metal contact sound when the headlamp assembly opens, other then that I have never noticed L or R on 1977 making any jerking motions.
Brian

 

[puppyfang]

so I take it, that it is the one that jerks open that should be looked at from your reply...right?

 

[bmotojoe]

From under the car I would look at the one that opens smooth watching how the linkage works. Move the assembly up and down several times noting all mechanical movements. You will get a good idea what is going on as how the linkage works. Then move to the other side that is in question and do the same, watching all linkage mechanical movements. Well this is how I would go about troubleshooting the problem. Again, if the headlamp assembly is moved full up it will lock up and you will have to start the engine so it will return to the down position.
Brian

 

[Vettehead Mikey]

Again, if the headlamp assembly is moved full up it will lock up and you will have to start the engine so it will return to the down position.
Brian

Not true, the headlights can be lowered manually by unlocking the 'knee joint' mechanism. No need to start the engine.

Additionally, a properly functioning system will be able to open and close the headlights at least once after the engine has been shut down. Most cars cannot achieve this today due to leaks . It doesn't take much.

 

[bmotojoe]

The only reason I suggested that one starts the engine if the headlamp assembly is locked in the up position is for a safety reason. I am sure that the mechanism can be unlocked manually, but I would hate to give someone advice that could result in a finger pinch. Once that the knee joint mechanism has moved past the locking point the four springs take control of lowering the headlamp housing.
For troubleshooting something mechanically for the first time with any type of stored energy behind it no matter how small, well I just would give it a second thought.
Brian

 

[Vettehead Mikey]

You'll probably find that the 'slow' side actuator has a pin hole leak on the front bellows. A relatively easy fix, parts are available at all the usual vendors.

Try that first.

 

[KOPBET]

Not true, the headlights can be lowered manually by unlocking the 'knee joint' mechanism. No need to start the engine.

I do this all the time too. The mechanism doesn't actually lock, it just won't bend back past over-center without pulling the joint back. All you have to do is pull the joint back the opposite direction past the point of over-center and down it goes.