This article is to show some of the variations you may encounter if you decide to rebuild Generation 1 (84-86) Fiero headlight motors. It also verifies some suspicions I’ve had about the motors and their components.
First, to identify the Generation 1 motors, look for a large flat wheel on the top of the motor. Some will have 2 small holes in the top, similar to what a dowel pin might fit into. Some will be smooth on the top. I believe the holes may have been used to position components during motor manufacture.
The Generation 2 used in the 87 and 88 Fieros has a small cone shaped wheel on the top. This article doesn’t deal with that style motor.
Upon disassembly of two outwardly identical motors from the same Fiero, I found different internal components. I’m sure one had been transplanted from another vehicle, since it had some paint marker writings on it, possibly identifying the salvage yard it came from.
Having prepared to rebuild the set, I ordered a Generation 1 rebuild kit for two motors. This kit includes 2 gears, bump stops, case reassembly screws and nuts and clips for attaching the mechanism arms.
After drilling and removing the case rivets, I opened the motor to find the usual green junk that previously had been the internal bump stops. I also found a large gear with stripped teeth. This was likely the reason the headlight wouldn’t lift unless given a little manual help to get it started.
I also found that the small gear was plastic. This is the first time I’ve encountered a small gear that wasn’t metal. So, it was discarded in favor of a more durable metal gear and a new large nylon gear. Instead of installing the Four rubber bump stops that came with the rebuild kit, I installed a material of my own.
These bump stops are what commonly come in the Generation 1 rebuild kits. They’re about .375 inch long by .375 inch diameter and install inside the large gear on opposite sides of the center. The ones shown here were removed from a previous rebuild when I couldn’t get the motors to stop Ticking. I found that the drive plate had compressed the sides of the pieces. They’ve been removed for about 3 weeks and they still haven’t returned to their original shape.
The gears were all lubed with a synthetic disk brake slider grease before reassembly. It’s a high temp grease and is safe for plastics, so it won’t cause the gears to disintegrate. Then the motor was reassembled and installed into the car. It worked the first time with no ‘Ticking’ as I encountered when I used the Four supplied bump stops shown above.
Then I turned my attention to the second motor, disassembling in the same manner as the first. Upon opening I found something entirely different than I’ve ever seen. The small plastic gear had straight cut teeth, as did the large plastic gear. The first motor used the small gear on the right. Both it and the large gear had angle cut teeth.
The small gear on the left and the large center gear are from the second motor, which probably is original to the car. The small gear on the right is from the first motor which I believe to be a replacement motor. You can see the straight cut of the left and center gears. Current rebuild kits have angle cut teeth, so, even though the center gear was good, the only small gear I had was steel and angle cut, so the second large gear from the rebuild kit was used.
For a long time, I have suspected that the original bump stops weren’t of the design that we commonly get with the various Generation 1 rebuild kits that are available today. I’ve been playing with some ideas which include casting pieces in poly urethane.
Instead of the green crumbs, this is what I found underneath the drive plate of the large gear. These are cast pieces and are the original factory bump stops. In my opinion this is a much better design than the round O-ring material that’s currently available with the rebuild kits.
These pieces straddle the ribs of the large gear with the drive plate keeping them captured. They are a tight fit against the wheel and the drive plate, so there’s no slop or bounce of the headlight assembly.
If you rebuild your Generation 1 headlight motors and find that the motors continue to try to run, I have bump stops available for $5 per motor or $8 for two motors. Postage not included.