C2 headlight motor problems including warped housing covers

[Daniel D.]

I’m attempting to repair my ‘65 headlight motors using an excellent tutorial by Alann Boatright. The motors are properly dated for my car, so I would like to keep them. I cleaned and removed the old grease and applied new grease. Both motor drive gears (the large pot metal gears) were significantly worn. I attempted to order new gears but they were on back order, so I rotated the original gears 180 degrees. The passenger side motor stalls when I install the gear train. The driver side motor has similar issues, but it will rotate the bucket slowly.

As a test, I removed the intermediate plastic gear and realized that the pot metal gear does not turn freely (by hand) after the housing fasteners are tightened. It is actually quite difficult to turn. As you can see in the photo, the gear housing cover (on the left in the first photo) is slightly warped. I’m not sure if this is causing the problem, or how I would find replacements (the covers are similarly warped on both the driver and passenger sides). I even tried two different used pot metal gears provided by a friend. I checked, and rechecked that I have the proper installation sequence of parts. First, I installed the curved spring washer (cupped toward the housing), then the small thick washer, then the gear, and then the nylon washer. Is this the correct order?

What am I doing wrong? Am I correct that the pot metal gear should rotate relatively freely when the intermediate plastic gear is not installed? Are the warped covers causing the problem (It seems that this would actually allow the gear more freedom)? Are covers commonly warped? Would someone be willing to sell a pair of covers that are not warped? Help.
Thank you.

[Richard M.]

Daniel, You are not alone.

Read through this thread HERE. It's a long one discussing your exact situation.

You will see details of your experience. Post #17 in particular shows washer placement variations. I also show internal dimensions of the gearcase, gear and washer thicknesses, and a summary of my research.

I have done many motor rebuilds and I am convinced that the housing covers have changed shape with age. Their internal depth shrinks, which results in the internal depth for the gear/washers to be too tight. It's the only possible explanation I've experienced.

Early(15 years ago) repro gears were too thick, but new repros are the same thickness as originals, as you'll see in my thread above. I show detailed measurements.

Keep your covers. All are the same. Some warp, like yours.

There are several ways to correct your problem...

1 - Using a lathe, shave the pot metal gear face.(my preference)

2- Grind the hardened thick metal washer to reduce its thickness.

The amount of material removed is a trial & error process.

I don't recommend adjusting thickness of the plastic washer. It's too delicate and difficult to fixture.

I've seen many with reversed orientation of the thick metal washer and conical washer. This works, but makes the gear too loose in the case.

Rich

[Harry S.]

Excellent solution by Rich.

A bit more expensive, but ---> https://www.ebay.com/itm/39614031838...Bk9SR8aYkdGyZg

[Daniel D.]

Harry and Richard, thanks for your replies. Richard, thanks for your detailed answer, and clarifying that I'm not alone with this issue. You've answered other questions I've posted in the past, and your help is greatly appreciated.

[Daniel D.]

One more update ... here's a picture of my friend and fellow NCRS member, Pat Boyd, turning my headlight motor gear on his museum quality lathe. I'm relieved to finally understand and solve the headlight motor issues.

[Patrick B.]

Well, museum age if not quality. It was used at the Washington Navy Yard from 1886 until some time after WW2 when an employee took it home. It is too worn out to make parts for the Navy, but it works fine on pot metal gears.

[Richard M.]

Patrick, Nice machine and setup to shave the face of the gear. How much material did you remove? If I recall, it didn't need very much based on my internal gearcase depth measurements.

Daniel, Please post your results when your done. I suspect you'll be better with the modified gears.

I'm still convinced the gearcase and covers change shape with age. It's the only viable explanation and I suspect all original motors have this issue.

Rich

[Patrick B.]

We assembled the gear in the housing without the steel washer and measured about .015 side to side play. Since the steel washer was .060 thick, that called for cutting .045 from the side of the gear. We cut .040 off of the side and reassembled the gear with the steel washer expecting it to still have a slight interference. However, we now had some side to side play with the steel washer in place. Clearly we took off more than what was needed, so our initial measurement of play with the gear in place without the washer was not accurate. I think Dan will try it out in the car to see if works right. If not, we have some more OE gears we can cut and reverse.

I don’t know why the measurement of side to side movement without the washer in place was not accurate. Perhaps, side to side movement was restricted by something else in the absence of the washer. If we do it again, we will take just .010 off and do a trial fitting to see if more is necessary.

[Richard M.]

Patrick,

You may be ok after it's generously greased up.

Rich

[Daniel D.]

I assembled the motor with the slightly over-trimmed gear that Pat discussed, and it seems to work fine. Hopefully we'll trim the other gear today.

[Mark F.]

...Well, museum age if not quality. It was used at the Washington Navy Yard from 1886 until some time after WW2 when an employee took it home. It is too worn out to make parts for the Navy, but it works fine on pot metal gears.

Patrick,

What make is your lathe ?
R.K. LeBlond ?

Bridgeport and Cincinnati were not in business way back then...

[Patrick B.]

I believe it is something & Lodge. I will check on Monday. I believe the company went out of business in 1886 which is how I got the date.

[Patrick B.]

Mark— I was browsing the internet and found a Lodge & Davis 1891 catalog showing my lathe. Lodge was involved in several lathe companies and Lodge & Davis started in 1886 and changed to Lodge & Shipley after 1892. They were made in 17, 19, and 21 inch swing models. Mine looks just big enough to mount a 15” Corvette wheel so it is probably the 17” model.

[Patrick B.]

Patrick, Nice machine and setup to shave the face of the gear. How much material did you remove? If I recall, it didn't need very much based on my internal gearcase depth measurements.

Daniel, Please post your results when your done. I suspect you'll be better with the modified gears.

I'm still convinced the gearcase and covers change shape with age. It's the only viable explanation and I suspect all original motors have this issue.

Rich

Rich— I think you are on to something about the housings warping and putting too much pressure on the gears. We did two more motors. One of the motors I had restored with an NOS pot metal gear for my 67 turned so much slower than the other one that I had to replace it with a whole NOS motor. I never understood what was the problem since you cannot rotate the pot metal gear when the motor is completely assembled. Trial assembling it omitting the gear driving the pot metal gear, as Dan did, revealed that the gear was very hard to turn in the housing. I cut 0.020 off the face of the NOS gear, and it became much easier to turn even retaining some pressure from the Belleville washer. Dan tested it, and it seemed to turn as fast as the other motors. We turned 0.020 off the second motor Dan had, and it seemed to work well.

So, it seems that a 0.020” cut on the gear face offsets the warpage issue pretty well, and hopefully the gear with 0.040 removed will work ok when the motor is installed in Dan’s car.

[Richard M.]

Rich— I think you are on to something about the housings warping and putting too much pressure on the gears. We did two more motors. One of the motors I had restored with an NOS pot metal gear for my 67 turned so much slower than the other one that I had to replace it with a whole NOS motor. I never understood what was the problem since you cannot rotate the pot metal gear when the motor is completely assembled. Trial assembling it omitting the gear driving the pot metal gear, as Dan did, revealed that the gear was very hard to turn in the housing. I cut 0.020 off the face of the NOS gear, and it became much easier to turn even retaining some pressure from the Belleville washer. Dan tested it, and it seemed to turn as fast as the other motors. We turned 0.020 off the second motor Dan had, and it seemed to work well.

So, it seems that a 0.020” cut on the gear face offsets the warpage issue pretty well, and hopefully the gear with 0.040 removed will work ok when the motor is installed in Dan’s car.

Patrick, Good news. Yes I seem to recall I cut about 15 to 20 thousandths with good results on most gears.

Rich