headlight on left goes up, then when turned off goes down and goes up again..fixed with new gears---turned down manually to close doesnt make a difference, goes down, when switched off then back up again. Right headlight works the way it should. help

 

Shims/spacers and the bump stops.

 

I'm not the OP on this but a week ago I replaced my headlight gears and they worked great, up/down, no problem.

I just disconnected the battery to check for any parasitic loads (none found) and when I hooked the battery back up again, that driver's side headlight popped up half way. Lights were not ON.

So, I turned the headlights full ON, they both came up, turned OFF, they went down and the driver's side popped back up half way again. Does it all the time.

OK, so I just found the correct link to the shim vendor:
http://rodneydickman.com/catalog/pro...roducts_id=285

I just add a couple washers between the motor body and the mounting structure?

Just from an engineering inquiry, why would the addition of the washers correct this problem and why didn't it occur when I first reinstalled the gears/motors. Just inquiring...Thanks, Bob

PS: Can I just head to ACE and pick up a couple washers? When I reinstalled the gears/motors, did I forget to put the original washers back between the motor and the car frame?

 

Back again, I just checked my Driver's side headlight and I do have bumper stops in place. Not missing.

So, adding the spacer washers would fix this? I don't see how but I'm willing to "invest" my hard earned $2.75 for the set of three if that's what it takes.

http://rodneydickman.com/catalog/pro...roducts_id=333

Any comments on why this fix would work would be appreciated, Thanks, Bob

 

This behavior is typical of damaged or missing rubber bump stops. In your case they are not missing, but even if they look fine to the naked eye, they might be scored too deep. You might need to replace them (4 per side). You can get them here.

In addition to that, there is a TSB addressing those symptoms that calls for shimming the driver's side motor (No. 2 in diagram):



When you replaced the gear in both headlight motors, did the kits include the T-Brace with plastic bushing to avoid glue failure? If yes, the T-Brace width (.05" for Rodney Dickman's) is already a bit more than half the recommended shim (.08"). If you want to get closer to the value, you can add 3 (1 per anchoring screw) thin stainless steel washers (.04") as I did.

As you can see in the diagram, the shimming moves the contact points that limit the door travel towards the base of the rubber bump stops (No. 4 in diagram). It seems that in the driver's side, those points were too close to the top end of the rubber bump stops, causing premature failure. The TSB was issued to correct this.

 

Yup, it was one of the Stoppers. It was not the pair that are at the back of the light housing, but the offending one was toward the front, down deep next to the motor.

Thanks to this wonderful BB, I got out my flashlight, looked down for something rectangular and white, and there it was. With a nice big wear mark in it.

Eureka!!!

So, as a test, I thought that I'd just pry it off and turn it around and while doing so it dropped down into the black depths of plastic duct-world, never to be seen again. So, So, I just removed one of the rear one's and (much more gently) and moved it to that lower one. Turned the headlights ON/OFF and the little driver's side monster goes up, and properly down. Parks in its little house as it should do.

So, I'll order a bunch of these. Looks like I don't need the spacers. I really don't want to take the motor out again.

Thanks again, Bob

 

You should do the spacers, especially if you plan to drive a lot at night. The spacers make the bar hit more in the middle of the bumper instead of out towards the edge, significantly reducing the wear on the bump stops.

 

Got Rodney's Spacers and Tabs. The old Tabs were really chewed up. Design error by GM on these things. The headlight swivel parts barely hit those Tabs, thereby eventually chewing off that soft end with the resulting, halfway up headlight problem.

In theory, by moving the motor more toward the radiator, with Rodney's Spacer Washers, the headlight swivels parts will hit more centered on the soft plastic Tabs.

Since I have many headlight parts that have dropped down into the black ductwork void down below, I dropped two of Rodney's new washers down there too. Very tight for even my small hands.

So, off to ACE for some new washers. Don't care of they are black like Rodney's. (Sorry Rodney, no time to order more from you but thanks for the very fast shipment...)

I think that I am going to double up on the washers, however, not just one as a spacer, but two or three. The headlight swivel parts really need to get further inward on those new Tabs and I don't see how just one Spacer washer is going to do it.

Any thoughts on my eyeballing design change?

Thanks, Bob (with scarred up hands from sticking them down into all those headlight parts).

PS: Did you know: Of the three bolts that hold the motor to the frame, the lower-forward one has to be fitted into the motor "before" you mount the motor. Once the motor is in place, such as with the other bolts, there is no room to slide that lower bolt into its hole. It has to be inserted into the motor hole first, then slide the motor/bolt into the metal support frame. Then the the other bolts can be fitted.

PPS: The only way to remove/reinstall the three bolts/nuts is with a 10 mm Ratcheting Wrench and a 10 mm standard Closed End Wrench. Make sure that both have off-set heads, not flat.

PPPS: To remove the old soft plastic Tabs, you need a long flat tip screwdriver to wedge the old one off. You can't do it with just your fingers.

PPPPS: At your local ACE, buy a bunch of metric 10 mm lock nuts since you will surely drop the old one's down into the ductwork, never to be seen again.

 

You just need to make sure the bent part of the arm can clear the tabs if you put on additional spacers. The arm makes something like a 270 degree rotation, or something like that.

 

Yup, just installed two washers between the motor and the frame. Works great.

I did install the rotating arm upside down so that when the lights were turned ON, the right one came up and my drivers side went down.

So I just undid the arm, flipped it around and now it works fine, up and down with its neighbor. (Take pictures next time, Bob!!!)

Couple more hints:

-Put a terry cloth towel (white) down under the light housing to catch falling nuts/washers. If they drop down into the maze of ductwork, you will never find them.

-I used a LED high power mini-flashlight to be able to see everything. Had to move it around a lot. A very narrow lens, about 1/2" would have been better. One of those on a flexible stick would be ideal so that you can see where the nuts are supposed to be.

-I put all three bolts through the motor housing before mounting it, and one by one, loaded the two spacer washers onto the protruding bolt. I held the washers to the bolt with a layer of masking tape. Otherwise the washers would fall off as you are installing the motor. (I left the masking tape on but it could be removed if needed).

-The offending soft plastic Tabs that have the effect of re-opening the drivers side light halfway, are the ones down deep under the headlight. There is one toward the front and one toward the back, about 2" apart. Even with the two spacer washers, the lever on the light swivel arm still only contacts the outside edge of this Tab. The Tab that is lower and further back seems to have a better landing pad now with the two washers. I would not use anymore than two washers. As per Tsumi said, that arm is moving around in there and it has to have enough room to swivel around.

Thanks again, got it fixed...Bob

 

It seems you missed my message above in Post 6.


You might end up overdoing it. As I mentioned in Post 6, chances are you installed a T-Brace as part of the gear replacement, and that count as a spacer as well. I took that into consideration and just added a "thinner" stainless steel washer in each anchoring bolt. After installation I checked where the bar was hitting the rubber bump stop, and it was perfect.

 

HI GCG,

There was no T-Brace in the gear kit. I didn't know about Rodney's parts when I bought the gear. I'll cycle the light a lot to make sure everything is working well, but so far, looks like it's fixed...Thanks, Bob

 

Sorry to hear that. I don't want to be the bearer of bad news, but it's better to be prepared

A steel T-Brace with plastic bushing is fundamental to reinforce the motor after glueing back its cover. It is designed to take away the forces from the gearbox plastic cover, especially each time the motor reaches its travel ends (which are hit very hard). Without it, the glue will likely fail.

​​​​​It can be separately bought. Take a look a this for more details.

IMO, Rodney Dickman's kits are the most complete and well thought out sets available.

 

Moved to C5 Tech.

 

OK, Back Again...

Went for a drive yesterday, opening and closing the Driver's side headlight to test "my workmanship". Noticed that it started to get a bit slower than the other side, then stopped coming up at all.

This morning I took a look at it and while the motor turns (as indicated by the **** on the back of the motor), the shaft is not moving at all. It looks like it has moved outwards and the nut on the shaft was right against the metal car headlight framing. Using a flat head screwdriver I was able to shove the shaft back into the motor (I could see the shaft metal end on the other side of the motor housing), but whatever went on in there (new brass gear stripped, shaft broke, etc.) the shaft is not moving. I had thought that maybe I could get the large brass gear to realign with the motor gear, but nope.

The problem is that I can't get the headlight up so that I can remove the motor. It's stuck down. Turning the motor **** spins (probably) the motor but doesn't move the shaft. Can't get the fiberglass headlight cover off unless I can get it up a few inches.

So, any thoughts about how to get the headlight up? Not enough room in there to get to the shaft nut.

Thanks, Bob

PS: The local dealer wants $451 for a new plastic housing motor/$342 for the newer metal housing motor.

 

Back Again (I'm just posting these "blow by blow" moments in C5 history to help others out, so if it's boring, please ignore...)

Got the shaft nut off. Used a "shorty" 10 mm open end off-set wrench. Just enough room to move the nut to flip the wrench around a couple times. After it was loosened, I used a long flat screwdriver to shove the nut, thread by thread till it dropped down into the black hole of ductwork pits.

The headlight can now be moved up, the covers removed and then I'll take the motor out and see what's the problem. Not going to fool around with gear replacement again. Just going to replace the entire motor. (Time/Money). If anyone knows of a good on-line shop that carries these at a cost less than the above quoted dealer prices, please pass it along.

Thanks, Bob

 

Yup, the glue joint failed when I had replaced the gear. So, "T-Brace" next time. Didn't know about it when I ordered the new brass gear. Lots of black plastic bits inside of the motor housing. Lots of torque going on in there.

So, new motor coming up...Thanks, Bob (With T-Brace!)

 

When I began reading your messages from today I immediately got the hunch that the glue had failed... Sorry to hear that

I can understand how you feel, but don't let a bad replacement kit frustrate you. Is the motor salvageable? If yes, you probably only need a new internal rubber damper/isolator and the T-Brace to get many years out of the repaired motor.

As I mentioned in my previous post, those components can be separately bought from Rodney Dickman.

Note: if you also replaced the gear in the passenger's side motor, I suggest you add the T-Brace before the glue fails.

Good luck

 

Morning GCG,
Thanks for the continuing hints. I'm just going to buy an entire new motor and be done with it, plus the T-Brace, just for the Driver's side. I didn't replace the gear in the passenger side and will hold off on that. Works great.

Now just looking for a good source for the motor/T-Brace. Needs to be a good one, but I have no need to spend the $451 from the dealer.

Pass along any vendors on this BB who might offer them. Thanks, Bob