Headlight motor keeps running

[charleshwhite]

John

OK, FWIW black2 is fixed.

Zip provided the parts and also provided detailedinstructions on their web page.

However, we succeeded because Boomdrive providedcritical input which allows us (me and "the" mechanic) to reorientour perspective and thinking. Vetteoz provided additional critical visualreferences which also proved crucial in confirming where we were and what wewere looking at (the Zip images were a wee bit small for us to see as clearlyas we really old geezers would have preferred late at night) TedC offeredgeneral comments and observations which provided very important guidance at keymoments when we were hesitant to continue. Roger's insights from his experienceand technical solutions to the challenges he encountered were also very helpfulparticularly in working on the Passenger side assembly and working around theproblem. .

We did the Driver's side first and found that theactual work time was a little less than an hour. We spent more time reading thedirections and comments and looking at pictures than working on the assembly. Istrongly recommend doing the Drivers side first since that is really straightforward and resolves all the uncertainties of locating things and figuring outhow they disassemble and reassemble.

We then did the Passenger side second. As has been noted thatis the more difficult side to complete. The gasket that fails IS the passengerside. One should order replacement gaskets since they are NOT in the kit thatZip sells. As TedC advised loosening the motor on the Passenger assembly doesassist the work process and allows the worm gear to offer less restriction onthe removal and reassembly of the bushings/gear wheel. GREAT patience isrequired when working on the Passenger side assembly because of the"ridge" in the gear well. When all of the stars are aligned itslips together very easily; but, until that happens it may try your soul. Itreally can't be forced and it just seems to fiddle with one's sanity until itjust slips together.

The nylon gears on both units did not look as ifthey had experienced any wear. We could have used them again but we replacedthem anyway out of an abundance of caution (and we had the parts) but the oldgears have now been cleaned and except for a little yellow age color look asgood as the new ones. The torque bushings were MIA and all that remained in mycar was a little porridge consisting of old lithium white grease and very veryfinely ground nylon.

In the end you only really need the torquebushings. But from my perspective I would replace the gears and use new gasketsfor a complete refurbishment of this function. It is also interesting to notethat the Passenger assembly only took an hour and ten minutes +/- on the bench even with thedifficulties noted above. The units run flawlessly.

Hope this helps John and again thank you to everyone for the comments, assistance, and encouragement.

CAC members are CHAMPIONS!!!!

Charles

[boomdriver]

Glad to hear that you made it though the rebuild...first time is always stressful. Once done, its now childs play.

Enjoy the springtime with some headlites that go up & down !

[John Robinson]

OK as soon as I suck up some courage I will tackle the passenger side only since the other side is working OK. I am from the old school if it ain't broke don't fix it. I am still a little fuzzy on how to remove the gear. If i understand what has been said I will have to pull the motor from the gear housing in order to somehow remove the worm gear and release the nylon gear so it will move up the shaft and expose the bushings underneath it. Which brings me to the problem of the brushes on the motor shaft. Someone mentioned using a paper clip to slip all that back together. How does that work? I always have a problem holding them back against the spring tension until I can get the shaft in between them on other things I have worked on. I suspect there is no access room to use something to hold them back. Unfortunately I have began to lose the dexterity of my fingers. I have new invited guest Arthur and his wife Ites have come to live with me.

[charleshwhite]

[Boomdriver:

Thanks; Driving? The local TV weather isforecasting "SNOW" starting today (4/21/12) and going through Tuesday(4/23/12) morning. This is the strangest Spring I have experienced in my life!

John:

As we all know I am NO EXPERT but (that is not going to stop me):

1.) I encourage you to carefully reflect on your present decision to only do one side. I am almost certain that the left side is in nearly as bad a bad shape as the right side.

2.) Starting on the left side will allow you to exercise the procedures without getting wrapped around the maypole of the "ridge" in the right side assembly.

3.) Regardless, on the basis of the comments received from others here I strongly advise you to "NOT" pull the motor from the gear housing in order to somehow remove the worm gear and release the nylon gear so it will move up the shaft and expose the bushings underneath it. As I understand your comment.

4.) The motor must be removed from the headlamp assembly and operating mechanism. This is in and of its self an interesting exercise in "technical reverse engineering" (jiggling the component).
(4-1)Selected features of the assembly "WILL" have to be loosened to allow access to the appropriate fastening devices (here we could have saved between 10-15 minutes per side if we had simply had magnetized screwdrivers/torex/etc or a shop magnet).
(4-2)The motor and gear housing is an integral unit. Once the component is on the bench separated from the assembly, removing the gear cover plate allows removal of the gear (remember to do this gently because of the fragile gasket). You need to be careful in doing this because there are flat brass bushings that may be lost in the thrill of getting the thing apart.
(4-3)Remember, the assembly appears to be one unit, but it is composed of:
(a) a gear,
(b) three torque bushing (consumable),
(c) a combined torque armature and axle assembly, and the
(d) brass bushings.
(4-4)In theory the gear and the torque armature and axle assembly will just lift out (remember the flat brass
bushings as they "MAY" come out with the assembly or remain in place??).
(4-5)THERE WILL is some resistance from the sacrificed torque bushings which will look just like either course ground flour or the porridge I experienced. REMEMBER. Loosening the motor housing slightly goes a long way towards easing the removal and reinsertion of the entire gear assembly.

5.) The unique characteristic of the passenger side is apparently the "ridge" which requires a little extra relaxation of the engagement tension between the worm drive and the gear face (I think). Please DO NOT do more that loosen the motor housing. This will require more intense "technical reversing engineering" for both the dismantling and reassembly of the motor/gear component.

John, for the record, I used my mechanic for this evolution because I have problems with my retinas. My vision is corrected to 20/20; but dealing with "small" items is problematic for me and situations where I must get "close" to look at something with low light and or different visual accommodation factors is very, very troubling and is NOT correctable. In retrospect, the only thing in this evolution that "might" have caused a problem for "me" was the "pin" removal. I just didn't know what to expect. However, I was pleasantly pleased to discover that these headlight components are very robust and not prone to accidental damage from sight impaired or ham fisted mechanics. However, not keeping track of the various parts that may be placed on the bench is sure to cause one to question one's own skill sets.

Finally, to fix this you simply need the "torque bushings" and a copy of the Zip instructions, the visuals from Vetteoz, and TedC's and Roger's comments and observation. I recommend having the Zip document in front of you at all times. The visuals are easily relatable to the Zip instructions. And when you think you might have a problem TedC and Roger have observations and suggestions to help. Since you are going to open up an assembly I strongly urge the inclusion of a new gasket. It appears that the nylon gear is robust enough to not have been damaged by the failure of the torque bushings so replacing the gear is purely an option (remember we only changed ours because we had them). ALSO DO NOT FORGET TO APPLY A LITTLE WHITE LITHIUM GREASE TO THE GEAR before reassembly. It should take only 4-4.5 hours for both assemblies unless one has to make tool runs. I hope this provides a little more clarification.

Charles

[John Robinson]

Ok today was the day to work on the headlight motor. Thanks to all of you for your input I used a little of this and a little of that and got it done. Along the way I also created some more information on this job.

Yes the bushings were gone. I had a piece of high density 1/2" nylon dowel so I cut a button and found out it was a little to big in diameter. I took a piece to my drill press and turned it down to the right diameter and then cut off three pieces that fit perfectly.

Now I had the problem on getting the nylon gear to go back over the worm gear. For some reason the gear was molded with a solid band under the gear teeth. I took a three corner file and notched that band with three of the tooth valleys.( The worm gear only cathes one maybe two teeth ) I located this at the tip of one of the corners of the triangle that is molded on top of the gear. I did this so I would be able to find it later if need be. Once I lined up those notches to the worm gear the whole thing slide back into place without any effort.

On another day I think I will look into the right side bushings.

Thanks again for all the help. Each piece of information added to my being able to make this work.

[John Robinson]

Well after doing the right side this morning and resting till after lunch I went out and tackled the drivers side. I see now why some of you said to do that side first. It was totally different then the other side I took off the cover and there was the back side of the gear with the buttons right there. All three were very yellow and so I went ahead and replaced them. They looked like they were beginning to flake some also.

both work now if I could just see at night to drive then.

[Coyote]

I have a 96 LT4 and noticed recently that the passenger headlight motor would continue to run for a few seconds after the headlights were turned off. Found great information on this site including where to get the plugs to replace the ones that turned to dust. I bought them at Autozone for $8.99 They are Ford window regulator plugs. I found the part number on the Autozone website and then went to the local store and bought enough to do both headlights. The driver's side wasn't as bad but had already started to crumble. I should be good for another 16 yrs!

[CharlesBrown]

An other loccation is Home Depot. They are about 30 cents each in the fasteners dept. Look for nylon "spacers."

[Coyote]

An other loccation is Home Depot. They are about 30 cents each in the fasteners dept. Look for nylon "spacers."

Wow, I never would have looked there! That's way cheaper than the alternative!!!

[TedC]

GM used delrin not nylon because it offers better compression strength. Will nylon deform over time in this application? Does GM know something we don't? Not sure which ages better, but delrin seems to good for 20-25 years.

[Coyote]

Not too sure about the compressibility of delrin and nylon. The delrin only lasted 16 years in my case (1996 model). As far as deforming under pressure, there isn't a large amount of force required to roll the headlights. When the motion stops, there shouldn't be any force on the bushings. Their purpose is to absorb shock and transfer the torque from the outer gear to the inner hub. Nylon may deform a little more than the delrin but probably not enough to matter. It will probably last a long time. I have read where some have even used wooden dowels successfully. Now that was a clever idea.

[roger longman]

You just need to use something that will wear out before the gear wheel, for obvious reasons. I have experimented with different material in other similar motor assemblies, even wound up elastic bands will work. Regarding the terror that seems to be associated with the removal of the worm drive, it is not at all that difficult. I used 2 paper clips, bent suitably, so that I could holde the 2 bushes apart, with one hand, whilst I inserted the worm drive with the other. And I am not at all dexterous........Roger.

[Coyote]

Roger, I have learned so much from this site from guys like you. Sometimes, I learn after the fact! When I was replacing the bushings in the headlight drive assembly I ran into the same problem of getting the big nylon gear out of the case. The first one I did, I removed the motor stator assembly. Of course, then you have to deal with getting the thing back together. As mentioned in previous thread, you can use paper clips. However, on the second one I did, I just loosened the two screws that hold the motor on and had enough movement to be able to lift out the nylon gear. Saved me a little time and hassle.

[roger longman]

Coyote, Yes, the passenger side can be done by simply removing the gear but, the other side, no, unless you file it. I decided not to do this, hence, why I removed the worm drive........Roger.

[Coyote]

I didn't have to do that to mine. Must be a difference in the model year. Just loosening the screws worked for mine.