C2 Headlight motor repair

[Ed S.]

Need advice on a problem I ran in to while repairing headlight motors for my '64. First - i have searched hundreds of threads on this forum and other sources, have only found two options - neither one easy.

Background: Motor is out of the car and on my work bench. I removed the armature from the motor - the bronze bushing came out with it - the bushing was really stuck (frozen) on the shaft. I managed to get the bushing off of the shaft without damaging it or the shaft - I cleaned up both and the bushing now goes on easily and rotates freely when on the shaft.

The Problem: I can't get the bushing past the bearing retainer that holds in in place inside the motor. Is there a trick to getting the bushing back into the motor housing in its proper location behind the bearing retainer spring which is held in place by a retainer ring, which is tack welded to the inside of the motor housing?

I see two options:

1. Grind off tack welds that secure the retainer ring to the inside of the motor housing with a Dremel tool; position the bushing and reinstall the retainer and secure it with dabs of JB weld around the perimeter (this was proven to work as demonstrated on a heater motor by 2 NCRS members).

2. Grind the spot welds off the back plate of the motor, remove the back plate, install the bushing and have the back plate tack welded back on to the motor housing (this option will leave tell-tale evidence of a repair job).

All that said, is there a way to get the bushing past the bearing retainer spring and in its proper position without resorting to options 1 or 2 above?

Thanks for your help.

[Richard G.]

Re: C2 Headlight motor repair

This is a link to a well written article on C2 headlight motors written by Alann Boatright. It sadly doesn't address your issue with the rear bearing except in a general fashion.
It may help with the rest of the rebuild however. For me the most difficult part was getting the rust removed from the housing. It is my understanding they were bare steel as installed.

https://www.ncrs.org/mvc/TECHNICAL_ARTICLES/C2%20headlights.pdf

I found that blasting the Aluminum housings with a soda blaster left the casting looking like they just came from the casting house.



Installed and ready to go.

Be careful as the small tang on the mount can off break easily. I used a impact screwdriver to tighten this bracket to the housing.
The results was a $65 dollar hit to the wallet.



Rick

[Ed S.]

Re: C2 Headlight motor repair

Rick - thank you. I have that article - it was (is) very helpful. I have several others that collectively, walk and talk you through the rebuild process, with one exception - the bronze bushing. As for the the rust on the housing - with the motor disassembled it was easy to get all the surface areas up against a soft 6 inch wire wheel, that knocked the surface rust off in a heart beat. A light coat of RPM will prevent it from rusting. Thanks for the tip on "the small tang" - I successfully removed the motor & disassembled it without doing any damage. I am on motor # 1 of 2.

[Richard G.]

Re: C2 Headlight motor repair

I have read an article that explains the bearing insertion process before. I have been unable to find it again.

A note on getting your motors to open simultaneously;
I bench tested the motors many times and had them apart over a dozen times before I was able to solve the issue of getting them to open & close at the same rate. Here is what I found;

After cleaning/rebuilding I recommend running the motor by themselves. I.E. without the gears installed in the box. This will confirm you have assembled everything on the motors correctly and they run to speed. They should run up to speed with the two motor to gearbox screws slightly hand torqued. It the motor speeds up when you loosen the bolts loose find out why. I set the motor end-play by hand tightened the small set-screw and then backed it off 1/8 turn.

I then assemble the gearboxes internals and used a battery to power them up. I marked the output shaft and average the time to make three complete rotation and record it. My output gears were new, with used gears the motor will slow, or even stop, as it goes through the damaged section of the output gear. I also used an amp meter to monitor the load on each motor as it rotated. I believe 5A running was average.

I struggled with synchronizing the timing and couldn’t figure out what the issue was until I noticed the large plastic gear was not running in the middle of the worm that is part of the motor’s shaft. I had to look closely to see this error in center-lines. I then manufactured a small washer that I could insert onto the shaft at the thrust ends to correct the offset.
This drastically sped up the slower motor/gearbox. After the modification the closing timing was within a part of a second. Synchronized timing keeps your aluminum gears in better shape as the output gear is the only thing that stops the motor while the other is still closing.

This was a very frustrating experience as I knew their had to be a reason for the speed difference. I had swapped the motors around in an attempt to track down the culprit. I even had a third gearbox to use in the troubleshooting process. I may have found it sooner if my eyes were better. Magnification really helps.

I hope this information is of some assistance....
Rick

[Ed S.]

Re: C2 Headlight motor repair

Rick -- Thanks for the great tips. Having disassembled just one motor I can see how its design and construction can affect its functionality as you describe. I have to tell you, I have downloaded and or read at least a half dozen how-to articles on HL motor removal / repair. None - not one mentions the issues and resolutions you describe. Thanks again - I will follow your advice to the letter.

[Gene M.]

Re: C2 Headlight motor repair

I totally cleaned out the pocket the spherical bushing fits in and installed a ball bearing. The b/b is what is refered to as a low profile bearing. The bore fits the shaft (with clean up) and the out diameter is reduced in size from a standard bearing. It uses smaller balls to achieve this. It is not considered a commercial bearing. As I seem to recall it is an ABEC1 class bearing. I epoxied the outside diameter in the pocket and slip fit the armature shaft in the bore. I may have polished the shaft for a snug slip fit. All this was done close to 30 years ago for my 65. Understand this is not a total fix all. Over the years of use the big aluminum gear is chewing up again. This causes the simultaneously opening to be sporadic.

[Alan D.]

Re: C2 Headlight motor repair

I too have had such happen, like Gene's solution best, have not tried yet.
The Back plate comes off without much effort so to put back -- trying using some epoxy. The new auto body stuff is great otherwise JB Weld
If you take your time almost nobody can tell (However somebody will be able, just hope it's not your judge)

[Ed S.]

Re: C2 Headlight motor repair

For all those following this thread and the few that have responded I want to let you know what I've learned. A fellow NCRS & chapter member contacted me via PM and informed me that he has restored dozens of C2 HL motors and it is virtually impossible to get the bushing back in without removing the retainer or the back plate of the motor case. Then, he offered to do mine - to remove the back plate, insert the bearing, then tig weld the plate back on and lightly grind the welds down so they are virtually not visible. I have already shipped my HL motor case and parts to him for the repair. Is this a great organization or what! This is not the first time an NCRS member that I casually or do not know by name had done a great favor for me - I just wish I had the ability to repay them in kind --- and help others as I have been helped.

[Mike T.]

Re: C2 Headlight motor repair

Ed - Those headlight motors sure can be difficult to work on when it comes to that sperical bearing. I had a similar issue with the motor in my 65 Coupe. Here's the writeup on the same sort of approach.
https://www.corvetteforum.com/forums...-retainer.html

[Richard M.]

Re: C2 Headlight motor repair

This is the method I used.

https://www.forums.ncrs.org/showthre...463#post762463

and a similar process for a heater blower motor here...
https://www.forums.ncrs.org/showthre...-How-to-Repair