Headlight Actuator Repair Kit, Corvette, C4, 88-96
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- Опубліковано 7 вер 2024
- www.corvettepa...
Two Kits Required per Car. 1 kit per headlight.
Inside the 1988-96 headlight motors is a gear which turns the lights. From the factory, the inside of the gear is packed with a special hard gel that turns the gear. As time passes, the gel deteriorates and no longer has the strength to turn the gear so it free wheels. Our headlight repair kit, consisting of 3 specially made Delrin bushings, replaces the gel and makes motors operate like new. One kit repairs one motor.
I believe on the passenger side, you have to slightly unscrew the motor case in order to get a little clearance in order to be able to remove the plastic gear. Which from what I've read, you don't have to do that on the driver side. I sprayed those little screws with penetrating oil the day before as I've read of some snapping those off when trying to unscrew.
I know for the 1989 Corvette some of the passenger worm wheel gear shaft assemblies are longer (less shims) depending on what was needed in assembly to meet the required clearances. If you pull the motor back be careful not to lose the ball thrust bearing (it is just a small single ball bearing) at the tip of the worm gear. It can be held in place with a little grease. There is an access hole to see the ball and tip of the worm gear, and an adjustment screw to set the thrust clearance (which you shouldn't have to move as it is set at the factory). In some instances you may have to pull the motor out beyond the brushes, which can be very difficult to reassemble unless you have the tools to hold the brushes or you can get a helper to hold the brushes back with a couple of thin 90 degree picks. Pulling the motor allows cleaning of the commutator, inspection of the brushes, cleaning the motor shaft and lubricating the shaft bronze bearing (bushing). Put some grease on the end of the worm gear to hold the thrust ball in place during assembly after cleaning.
In some instances even if you use penetrating fluid you will still twist off the head because the screw threads are rusted (welded) to the aluminum casting, this problem is more prevalent with corvettes that come from the rust belt (winter road salt spray). The one method that might work for rusted threads is to apply Knock'er loose penetrating solvent (which works exceptionally well when used with heat) and then carefully apply some heat (but not too much that it melts the motor housing rubber seal), if the screw moves just a little add some more penetrating fluid and work it in by moving the screw in then out in very small increments. It will eventually come out. If after all this it doesn't move you will have to twist off the head then drill out the screw over sized, thread and install an 8-32 Heli-coil.
@@windward2818 I replaced the bushings in both motors a few months ago as my driver side started acting up. And on the passenger side I had a bolt snap when trying to unscrew the top hat cover housing. And I drilled through and got a bolt, washers, and lock nut and used blue threadlocker. It ended up I didn't even need to try to loosen those bolts as the previous owner had already done the passenger side, and there was a brass gear inside that is removable without having to loosen those top hat cover bolts.
Perfect video, couldn't have done it so smoothly without, if at all... Thank you!
Thanks again Lyle. Great video. Easy to learn
I've read people recommend coating the three bushings with grease too. Which is what I plan to do unless there's a reason you shouldn't that people aren't aware of.
Chris Fix used high temperature grease on the bushings and brass gear. I'm planning (already purchased) the brass gears and plan to install those in mine. I agree with Lyle's comment that the plastic gears would be a better option if something prevented the motor from moving the headlamp assembly. Having a plastic gear fail would be better than a motor failure. I'm gambling a little here, but believe the odds of the assembly being obstructed is small.
Excellent how to video. You covered every aspect thank you very much..
I had to do this to both of my headlights... It's not that bad
That "stamped steel arm", i.e. triangle silver piece next to the motor was missing on my driver side. Don't know what it does, but I guess it's not critical since mine has gone years without it on one side.
It is not critical--they actaully stopped using it at all after 1993 (if my memory serves...) Lyle
By bearing grease do you mean wheel bearing grease? If it is petroleum based it will not play nice with Nylon Plastic. You should use plastic gear lubricant which has a wide operating temperature. For the bronze bushings (bearings) lubricate with a light machine oil with a high temperature rating.
I sanded the top edges of the pucks a little bit, to help the carrier assembly pop in. I can't help wondering why the drive system is configured this way. I mean, why not just key the gear directly to the carrier? Why do we need this bizarre puck system? The only explanation I can think of is that it allows for some expansion and contraction caused by temperature variations, which are pretty extreme. Think Canada in the winter versus Florida in the summer, which can be 150(F) degrees of temperature differential. Under those conditions, a plastic gear tightly pressed onto a steel shaft is likely to crack and fail in short order, due to the stress of being 'stretched' over the shaft.
Maybe this setup combines zero play in the drive's action with relatively long life before failure. And that, in turn, makes me wonder whether the brass puck and gear alternative, which I considered, is such a good idea. There has to be a bit of slop in those brass components so they can be assembled. That might lead to your headlights jiggling slightly as you go down the road.
The pucks (pellets) provide the locking mechanism and also help keep the assembly "slippery" as they are made of Delrin, which is very slick. The brass gear issue is that they remove the "fail-safe" of a cheap plastic gear that the system sacrifices if there is a obstruction to headlight rotation--the brass gear will never fail, but if the headlight binds up you will kill the entire motor instead of just the $25 plastic gear. Lyle
Do you have a version of this video in Spanish?