Headlight doors won't open

Need to add my headlight door post.
It's a 74L

By motor gear, you mean the one on the motor shaft, right?

The headlight mechanism has a gear drive that the motor gear meshes with. It was a plastic gear with a metal hub. The plastic cracks and jams the whole shebang. Happens all the time as the plastic reaches the end of its life.

This same born-to-fail gear is also used in both door window gear drives.

Vendors have solid brass replacement gears for the nylon/metal OEM piece. Often only noted as being for the doors, but it is a direct swap for the headlights, too.

Look into your gear drive assembly. Pretty sure you'll find the problem.

Larry

Hi Larry,

I think the gear you are referring to is in the motor/drive. The motor turns and the gear that meshes with the 1/2 moon gear that connects to the long bar that turns to raise doors turns good in both directions.

Am I correct that the gear you are referring to is in.The motor drive?

I have replaced the.nylon with brass gears on window.motors.

Steve

Since you've replaced the gears in the window mechanisms part # 49 should look familiar. This where the gear is that Larry was referring to.

What may be happening in your case is the plastic gear has not totally failed and functions OK when disconnected from the assembly and allowed to turn freely. However the load and weight of actually moving the entire headlight bar assembly may be causing the inner metal hub to disengage due to small cracking rather than total gear failure.

Have you actually viewed the plastic gear in the headlight drive mechanism?

Larry

Hi Guys,

I was not as clear as I could have been.

The problem is this. With motor drive gear not touching the ½ moon gear connected to shaft 67, there is no load on motor or motor gear. So with no connection to motor at all, the problem is I cannot move shaft that raises the doors.

The door opening shaft, 67, won't rotate to raise the doors. This is with NO CONNECTION or load of any type on the motor or motor gears. Shaft 67 is isolated from the motor and gears.

There is something that is stopping shaft 67 from rotating to open the doors.

Does that help

Steve

...Poor Eyesight?
The Part you are referring to is #57. It is Tubing.
Sounds to Me, the Tubing is Badly Rusted and Is LOCKED with-in the 'Larger Tubes'(or is it just a couple of Holes in the Sheetmetal?), it must rotate in.
OR...One of the Headlights may have 'Popped-Out' of its' Holder, or something has come loose and is Jamming against the Body, Preventing the Housing from Raising!?
Also, we just Recently, had a Thread here about the Plastic 'Bushings', the Tube Rides In, Disintegrating and Disappearing. THAT along with the rust would certainly Lock-Up the Mechanism!!
Remove Both Splash Shields and Inspect it.
Keep Working at It, You'll find the Problem!

Good Luck!

I'll check that out and remove the panels.

Hope it's something obvious that I missed.

Thanks all for help.

Will keep you posted

First time I used forum and great and very quick replies.

Need to use more

Steve

Steve,

Are you aware of item #45?

It is a knob that is depressed and then manually twisted to, or so VERY slowly, raise the headlights when the motor zonks out.

I'm not even sure this could be the cause of the bind, but so goes long distance troubleshooting.

There is a lot of cantilevered weight on that headlight bar. I'm not sure how easy it truly is to rotate by hand. Perhaps someone else has experience on that?

As the diagram below shows, there is really nothing but the 1/2 moon gear to get in a binding situation.

If is IS perhaps just too heavy to rotate manually as opposed to being jammed, THEN I would go back to the condition of the plastic gear.

Larry

you are referring to item #38 in this diagram, right?

+1 on the fact that the headlights and buckets are pretty heavy. You might try to raise the buckets a little with the tubing but get someone to help you and GENTLY together lift on the bucket front edges to see if they really are stuck .. no forcing allowed.

Yes, I am referring to shaft #38,

This is driven by the motor gear turning the 1/2 moon gear.

I moved the motor so the drive gear is not contacting the 1/2 moon shaft drive gear.

So at this point the shaft should rotate freely. I connected a vice grip to the shaft and with a lot of force doors lift about 1/4 inch.

Your suggestion that maybe a light is out of the bucket and binding. Possibly the chrome retaining ring came loose from one of the lights and is jamming a bucket.

I'll focus on what is stopping shaft from turning.


Back soon with details

Steve

Don't know where you are in Maryland but Ron McCall is in Hampstead. Knows the Pantera inside and out.

Hi Guys,

When moving the buckets over the very short distance they were able to travel I traced a noise to the passenger side light, that I heard when the lights stopped moving.

Removed the right front tire and wheel well panel. Then eureka.

A few years ago I drove the right side of the car against a tree stump. Hit very low on car so the damage was not visible from standing near the car. But looking into the open area at the headlight buckets I could see that I had pushed up the sheet metal beside the parking light.

When the bucket rotated it hit a vertical sheet metal seam (where two pieces met) and stopped the bucket.

Finding the problem was easy after I removed the panel, pulling the sheet metal down I had to be creative but got it done.

While I have everything open, I think I'll go ahead and change the nylon gear to the brass.

May need some help with getting the motor out.

Thanks for all the input.

Steve

PS, I know Ron and a couple of weeks ago about 9 Pantera owners traveled together to a car show.
Ron has an amazing car,

Eureka!!!

Well done, Steve.

Larry

Great Job!!!
Glad to hear you have it all working.

Pulling the headlight motor is a bit tight without first removing the radiator.
Might be a good time to consider pulling the rad, doing a coolant flush and change the gear at the same time.

At first I thought it was the gear in motor so I have removed the fans and tilted radiator forward and took out two bolts holding the bracket the motor is mounted on. That's when I was was able to see the motor gear that drives the ½ moon gear was turning OK.

I may need some help getting motor out. I understand it could be a little tricky.

.
I should consider removing radiator and getting it flushed and serviced.

What year is your car.

Thanks for your input.

Steve

quote:

Originally posted by Steve H



What year is your car.

Thanks for your input.

Steve

The orange one is a 72, but I have sold that one. I have a few others, mostly 72's
I tend to buy light project cars, clean them up and sell them on so I usually have a few on hand. I do tend to favor the Pre - L's

I've only had my 74. drove it out of the showroom.

Sounds like you can be a good source of technical info.

I've done all repairs as needed on the car without much problem.e

Looks like the Orange 72 was a real head turner

steve

Thanks but actually I get most of my info here on the forum from reading posts from Boss Wrench, Marlin Jack, George P. and others
Those are the guys that know these cars better than anyone