Headlight Motor Repair Procedure
The following instructions detail
the repairing of the headlight motors for the C4, using
1/4\” drive 10mm socket
1/4\” drive 13mm
1/4\” drive Torx #30
Nutdriver with 1/4\”
Awl or sharp nail
snap ring pliers
2 Ecklers #29304 kits or
(additional instructions come with the
Step One: Marking the position of the headlight
This step will ensure that you can replace the headlight
assembly in its correct
alignment in the headlight opening in the hood.
First, open the hood. Take an awl
or sharp nail and scratch along the
headlight mounting brackets on the underside of
the hood. Do this on
all mounting brackets. Try to get as close to the brackets
Step Two: Disconnect the wiring
The motor and headlight each have an electrical harness
plug that must be
disconnected to remove the headlight assembly. Follow
the wire from the motor and
disconnect the grayish colored connector.
The headlight has a similar one that is black.
Step Three: Removing
the headlight assembly.
Use the 10mm socket and remove four
mounting bolts. There is a small bracket
on the right side of the left
light (near the motor) that should be removed using the
13mm socket. An
additional 10mm bolt should also be removed from the bracket.
headlight assembly can now be placed on a towel on your work bench.
The real fun is
about to begin!
Step Four: Removing the
headlight motor from the headlight assembly.
1.Use a torx #30 bit
and remove two long bolts the hold the motor to the motor
Spray some WD-40 on the heads to help loosen them.
2.On the motor gear
shaft that passes through the headlight linkage you will
see a very
small retaining ring on the very end of the shaft. Remove this
with the snap ring pliers.
3.On the motor gear shaft you will see a
small roll pin that has been pressed
into a collar and the shaft. Use a
small punch (~1/8\”dia) and hammer this
pin out of the collar and
4.You can remove the linkage from the shaft. Be aware that there
are some very
small shims and parts that must be reassembled in the
correct sequence for
the linkage to work.
5.The motor should now be
free from the headlight assembly.
Step Five: Replacing the
This part will deviate slightly from the instructions
provided by Ecklers.
1.Remove the gear cover by removing the three
small hex head screws using a
1/4\” socket or nutdriver. Be carefull
not to snap off the heads.
2.Ecklers instructions say to turn the worm
gear adjuster 1-2 turns to relieve
the pressure on the spur gear. Mine
would not budge due to 10 years of
service, it was completely locked
up, so I did not perform this step. If you
can, count the number of
turns and write it down.
3.Ecklers instructions say to loosen the two
motor housing screws. I tried to
loosen one, snapped of the head and
had to drill it out and replace a screw.
I did not try this
4.Next, use your pliers to remove the yellowish gear that is
about 3\” diameter.
Be carefull and do not damage the shaft. This gear
will be tight if you can
not loosen the motor housing or back off on
the worm adjustment, but
eventually it will come off. There are some
small shims on this shaft that
you will not want to loose. What you
will have is a hollow gear with bad
bushings inside or in my case, a
bunch of dust. Separate the two halves and
dump out the dust and clean
the gear. Place the three new delrin bushings in
the triangular area of
the bottom half and replace the top half.
5.Be sure and clean the dust
and particles from the exposed worm gear, an old
toothbrush works good
6.Lightly grease the large gear and replace it back in the
housing. It will be
tight due to the way the teeth in the gear are cut.
A light tap with a hammer
will put it in place. Replace the gear cover
and reattach using the 1/4\” screws,
but do not overtighten
7.(optional) Tighten the motor casing screws and put the worm
adjustment screw to
its original position.
Step Six: Installing
the headlight motor back into the headlight assembly.
motor into the assembly with the shaft protruding into the collar
2.Insert the two motor mounting bolts into the motor bracket
and tighten loosely.
3.Slide the collar and linkage back onto the
4.Align the hole in the collar with the hole in the shaft and
press the roll pin
back in with a hammer and punch.
two motor mount bolts.
6.Reinstall the small snap ring onto the end of
Step Seven: Replacing the headlight assembly.
the alignment marks you made in step one to place the assemblies back
the hood, otherwise hood/headlight damage could occur when you
turn on the light switch.
Reinstall the small bracket using the 13mm
and 10mm bolts. Install and tighten the
remaining four 10mm bolts using
the alignment marks as a guide.
Before you test the headlights,
make sure that the headlights are in the closed
position!! You can turn
the motor by hand to rotate the headlight to its closed
Step Eight: Reconnect the electrical harnesses and
You can now reconnect the motor and headlight connectors.
Before you test the
operation it is a good idea to recheck the
headlight linkage for correct assembly.
Compare one headlight to the
other and assure they are the same. All that is left to
do is to tidy
up some of the wiring and turn on the lights.
These instructions have
been used and verified by several Corvette owners.
Headlight Motor Repair Procedure