'88/89 Glass Quads' Achilles Heel- The Adjusters!

DennisT said:

S....25, very interesting regarding the lights you found and the link you provided. I clicked on the link, found the lights quickly and was surprised. To me the ad seemed to be selling 4x6-inch lamps. If so, and if you used them, how did you get them into the '88/'89 sealed beam buckets???? When fighting these conversions myself, the only lamps that would fit 88/89 were what was called 150mm lamps. Smaller than 4x6.
Adjusters: a headache. Period. I spent several weeks on that. My truck was/still is inside waiting out the winter. So I could afford the time spent. I worked really, really hard trying to identify those adjusters, and the result was my post above with the photos. I finally found a couple on ebay. Here are some thoughts: If I were to bring home an '88 headlight housing complete with buckets, adjusters, etc., from a wrecking yard today I would sit down, get comfortable, and get out my hex-driver, sized to fit the, "top," vertical, adjuster shaft. Next I would get my thin, plastic compatible oil and put a drop on each threaded end and the area where the vertical adjuster shaft enters that little, "gear box." Then i would gently try adjusting. Back when I began, the wrecking yard units i had to deal with had 80% of the adjusters that would not easily turn, if at all. After soaking with additional drops of that oil, over several days, I began to get motion. Fast forward....I got 60% of my stuff working and had to replace the rest with other used or ebay adjusters. The, "short shaft," adjusters seem to be far more difficult to find/buy than the long shaft. Early on, I completely removed an adjuster and turned it's vertical shaft, whereby I discovered it merely rotated the second shaft. They don't adjust that way. The threaded shafts don't move in or out in that method of, "testing." When the adjuster is mounted and connected to the bucket, the square notch in the bucket prevents it's mating shaft from turning. THEN the gearbox behaves differently, and if all is working correctly, (as in...not broken), one can observe the threaded parts moving in and out and the bucket itself moves. That's why, now, the first thing I would do is lube, and try moving the vertical adjuster while everything is connected. But I would not force it. Once they began to work, I rotated in and out a little, lubed, rotated again, lubed, etc., etc., on and on. I've had at least 3 adjusters that never did, "come loose," and begin to work. Some eventually begin to work smoothly, some not so easy. I bought one NOS, on ebay, and it was balky right out of the package. I lubed that one a lot too before installing. Others on this forum have encountered what they describe as, "stripped," gearboxes. I've yet to find that. I've yet to understand how those little gearboxes work. Someday I'd like to cut a bad one apart and see how it works. They're weird. Let us know how you do with all this. Lastly, I'm still confused on what those lamps you are using are.......

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Scubaru25 said:

Thanks for the detailed response. When work slows down in the spring I'll tear into them and see if I can't get them working. All the adjusters turn freely and don't feel bound up at all so it's interesting. Any chance you could tell me which adjusters are the vertical and which horizontal? As far as the lights I used they are the ones from the link I provided. They are indeed smaller than 4x6 and designed for the quad beam Firebirds that share the same lights as the quad beam 88-89 trucks. I'll add some more pics

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