Headlight gear wont stop grinding !!
Thread Starter
Heel & Toe
Joined: Sep 2017
Posts: 21
Likes: 0
From: Virginia
Headlight gear wont stop grinding !!
I've looked it up and have followed step by step instructions on this forum to change the headlight gear and when I'm done it works for maybe a day or two and then starts grinding again. I have replaced the gear twice now and it just started doing it again 
. Am I doing something wrong? I been using the stock replacement plastic gears, and I'm aware of the bronze ones but I'm curious that if i switch will it eat up the bronze one also? Is there a certain way to adjust it to make it stop doing this? Any help or advice would be greatly appreciated because its starting to drive me crazy 
...
. Am I doing something wrong? I been using the stock replacement plastic gears, and I'm aware of the bronze ones but I'm curious that if i switch will it eat up the bronze one also? Is there a certain way to adjust it to make it stop doing this? Any help or advice would be greatly appreciated because its starting to drive me crazy ...
Thread Starter
Heel & Toe
Joined: Sep 2017
Posts: 21
Likes: 0
From: Virginia
Did you inspect the close and open bump stops to insure they were still in place and/or not damaged? The headlights are stopped by the headlight control module sensing a rise in current in the electric motor circuit when the headlight doors contact the bump stops and then cutting off power to the electric motor. Damaged or missing bump stops delay this occurring and can cause the motor to run much longer than it should putting unexpected torque on the gears.
Here is a thread that shows the open and close bump stops:
https://www.corvetteforum.com/forums...ght-shake.html
Here is a thread that shows the open and close bump stops:
https://www.corvetteforum.com/forums...ght-shake.html
Melting Slicks
Joined: Nov 2009
Posts: 2,922
Likes: 219
From: West Branch, MI
If you've replaced the plastic gears more than once, when you opened up the assembly, were the teeth on the plastic gears broken or missing? That's what causes the grinding noise and that's why folks use the brass gears as they won't break (within reason of course). The stops that 8Vette7 mentioned can be the cause of undue stress on the motor and plastic gears if the bump stops are worn out or the metal tabs are slightly bent. Adjusting those can help for sure. Also, if you'll notice, you have 4 bump stops on each headlight and they're all the same. You can take them off and turn them over if they're worn/broken/etc and you can swap them around as well. The brass gears will stop the noise but if the bump stop tabs are not adjusted correctly, they might tighten up too much upon closing, then not open when expected.
Thread Starter
Heel & Toe
Joined: Sep 2017
Posts: 21
Likes: 0
From: Virginia
Absolutely!!!! 
There is also a possibility that the headlight control module is the cause. As I mentioned it has logic in it that senses the rise in current to the motor circuit when the doors hit the stops and then shuts OFF power to the motors. The HCM looks like this:
http://www.ebay.com/itm/97-04-C5-Cor...5YNceR&vxp=mtr
And they are known to have the plastic cover over the electronics split and allow moisture to get into the electronics.
HCM is located under the passenger side headlight door assembly. Might be worth the time to inspect it............
There is also a possibility that the headlight control module is the cause. As I mentioned it has logic in it that senses the rise in current to the motor circuit when the doors hit the stops and then shuts OFF power to the motors. The HCM looks like this:
http://www.ebay.com/itm/97-04-C5-Cor...5YNceR&vxp=mtr
And they are known to have the plastic cover over the electronics split and allow moisture to get into the electronics.
HCM is located under the passenger side headlight door assembly. Might be worth the time to inspect it............
What I did was i turned all the bump stops over to fresh sides and then I removed the motor and inspected it. I found that the cover wasn't sealing properly and therefore the gear was loose and not making good contact with the worm gear. So what I did was turn the gear 180* to a fresh side of teeth and then upon re assembly I resealed it and used a thick washer with a big enough hole to go around the shaft so that way when I tightened the bolts flush the washer would press against the cover enough to keep it tightly sealed (similar concept to the "T" bar thing). This was all I could come up with, with what I had laying around the garage. I put everything back together and i worked perfectly and the cover stayed tight and everything was smooth when they rose and went down. I appreciate all the help and the links! I will definitely invest in the kit if this doesn't fix it.
