So does anyone know if NOS lexan t-tops are known to exist anymore? Weren't they discontinued long ago and original lexan tops were often swapped for glass versions at the dealership?

I ask because I just bought a bunch of stuff at auction, of a closed down Chevy/Olds dealer. I knew there was one in the pile of parts I was bidding on, but later discovered the 2nd one was in there too. Long story short, I now own a pair of NOS lexan tops. They are in incredible condition, it's really cool. I'll try to get pictures tomorrow when it's light out tomorrow.

 

NOS still pop up now and then. Whats the date code on them?

 

Haven't a clue, I'll have to look and post it. One of them was still in the remains of a box too, it might have a shipping date on it.

 

Yes, I know of at least two. A guy on this forum going by blackiroc something has some he just found. So yes, some exist.

 

Lol. What I meant was, a lot of stuff can still be found NOS without much trouble. But NOS tops is not something I remember coming across before.

 

I do not know how to decipher glass (er, window) codes, but here is one of them.




I believe they will polish up very well. The one out of the box does have a little chip out of one corner though.

 

That's really cool, I'm not an expert on glass either but looks to be 89?
possibly for sale?

 

I thought maybe '89, but only because two of those codes end in "9".

I've got mixed feelings on selling them or not. Definitely leaning towards keeping them.

 

When did the lexan tops start to get used in production? My old '89 had glass tops and my '92 has glass tops as well. I'm guessing they were replaced on my '92 back in the 90's.

 

89 was 1st year. Discontinued pretty quickly, then back in 92.
from the limited info i have.

 

I'm going to start with these factory T-tops are not Lexan™ (polycarbonate plastic). The are Plexiglass™ (acrylic plastic).

People probably got confused back in the day because the company that made them is named LEXAMAR.

They were first introduced for the 1989 model year and ran through the 1992 model year as far as I know. Cars could have came with glass or plastic T-tops. You can't tell which ones it came with by the SPID Label. It will just show RPO code CC1. Maybe the Trim Tags or Build Sheets will say which set of T-tops a car came with. IDK.

The one you showed the label for were made in June of 1989 (0689 date code).

The earlier Lexamar™ T-tops had a more pronounced dome than the later ones do. IDK exactly when this change happened. Of the 100+ 3rd gens that my friend has owned since 1986 and have been through his collection all the the 1990 3rd gens have been hardtops or convertibles. All the 1991 & 1992 3rd gens that had plastic T-tops were the low dome style. My 1991 GTA parts car had glass T-tops but they now reside in my friends driver quality 1989 TTA that had the high dome plastic T-tops, they were warped and cracked bad because it was a Texas car. My 1992 Firebird has plastic T-tops. His 1991 Formula has glass T-tops.

My 1992 Firebird was made (10/91) October 1991 and the driver side T-top has a date code of 0991 and the passenger side T-top has a date code of 1091. The label on my T-tops are the same as yours except for M-289 0991 & M-289 1091.


Blow the picture up and look at the trillions of "Stars" in my plastic T-tops. They aren't on the outside or inside of the T-top. I think they are between the acrylic plastic and the LexAR Coat 100™ scratch resistant coating.

You can see the label mentioning these are acrylic plastic. The "Starfield" is orders of magnitude worse in real life.

My computer is wanting to reboot for a Windows Update. I already had a reply typed out earlier today and I got busy and my token expired and I lost it. I'm going to install this update before it does something crazy and reboots on me. I'm going to post what I have now and edit my reply later on.

 

So upon further inspection after a good cleaning, as well as a bit of research... these actually aren't NOS tops, lol. The first indicator was that I noticed trace amounts of adhesive for the side weatherstripping. The second indicator was the remains of drilled out rivets that retained the lock cylinders. The third indicator was the part number on the one box, #12397247... which is for a glass top.

The GM parts listing I found shows these '89 acrylic tops (they are indeed a bit of a bubble top compared to glass) as being late '89 only. Then no acrylic tops again until sometime in the '91 production year, and they are a different part number.



At any rate, these tops cleaned up very well and I'm happy about that. There's just some light scuffs that need polished out.

 

Domed top on right vs flat top on left

 

Maybe the date code on mine aren't actually '89? Mine are domed a fair amount less than that. Unless it's just the angle and the lighting?

Here they are sitting on one of my 86's, they are just sitting there and not latched.

 

The date code is right. June of 1989. Very close to the end of the 1989 model year production in August of 1989. Like I said I'm not sure when the high dome acrylic plastic T-tops went away and the newer low dome acrylic plastic T-tops started.

I'm going to equate these T-tops to teenage girls chests. Glass T-tops = "flat chested", low dome acrylic T-tops = "Skeeter Bites", and high dome acrylic T-tops = "about ready for her first training bra".

The 89 T-tops you have and the 91 T-tops I have are "Skeeter Bites"

My guess is the acrylic plastic T-tops you have were from a customer's car that complained about them and the dealer replaced them with the glass T-tops. The dealer tech swapped the lock cylinders from the plastic T-tops into the new glass T-tops and put the old plastic T-tops into the boxes the glass T-tops came out of. Dealers swapped many sets of the acrylic plastic T-tops out with the glass versions due to customer complaints.

2 of the 4 1989 Firebirds in the collection have acrylic plastic T-tops. TTA #2 and TTA #3 have the high dome acrylic plastic T-tops. With TTA #3 having them replaced with the glass T-tops from my 1991 GTA parts car. I'll look and see what the date codes are on these T-tops.

 

Your guess as to why they were replaced was also my assumption. I'd guess it was done when the car was fairly new, if not new. The only damage/wear on them is from getting bumped around in the parts department for decades.

I forgot to see when/if the part# on the box was superseded, to possibly ballpark date when they were replaced. Obviously it would only date them (the glass ones that went on) before or after '91, at best.

 

I’ve been looking for a good set of the 89’ hump Lexan’s as a backup to mine. One of mine has a chipped corner. I have a set of NOS glass tops still in the box.

 

It must be a common problem. That's the only real damage to this pair I have. They both have a little (very little) piece chipped off of a corner. Likely not from use in a car, but from how they were stored and moved around. One looked fresh, I think it was from someone at the auction that was digging around through all the parts before bidding went on.

 

I forgot to ask, what is the part # of your NOS tops? Do they have dealer shipping tags with a shipping date on the box?

 

Not sure of the exact date but they are big pin tops. So 89 and up. They are not just cores. They have locks and keys.

 

I wish the same supplier who made the 4th gen style acrylic T-tops made the ones for the 3rd gens that always looked like trash.

 

I believe you're correct about it being a common problem with the acrylic ("domed") tops -- but I think the chipping was more frequently a result of stresses on the acrylic tops rather than mishandling (although the latter has probably contributed to it as well). My '89 Formula originally came with the acrylic tops and the corners have all since chipped. Even so, I've just left them on the car as the original equipment since I rarely removed them anyway; I've also never stored them off of the car. So the only conclusion I can draw for the damage is that the corners were broken off by the physical stress placed on them by the vehicle itself, probably the body twist. The driver's side top even has a crack in the middle of it, near the rear of the panel. Surprisingly, despite the damage, the tops remain water-tight...!

I also have two additional sets of tops for the car that I've acquired over time:

• A set of used glass tops, which I don't use; and
• A set of NOS acrylic ("domed") tops that I've only test fit to the car, then left off of it because I thought that might be best, given on the cracking suffered by the original tops. Granted, I've taken care in storing them to avoid damage, and the corners of these tops have remained intact.

 

The “star field” is what really bugs me about these tops. I acquired a second set of acrylic T-tops for my car due to a big deep scratch on one of my originals after I bought the car. I polished them out, but lost the “Lexamar” badging on the surface of the hard coat. I got a piece from a trashed top at a junkyard with the Lexamar badging and hope to have a decal made that I could put on my polished tops.

I have a set of mint glass tops on the car currently, but I really like the smoked look and much lighter weight of the acrylic tops. Too bad there isn’t enough interest in these cars to have a company make a reproduction set of acrylic tops.