New windshield, New rubber gasket, Doesn't fit !!!

[Green Machine]

I have a 1968 C10 Custom with the trim moldings in the front and rear glass. Went to body shop today, paint is done and he had front windshield and rear glass installed. I bought new rubber gaskets for both ends from LMC about 5 years ago when I installed rear slider. Reused rear gasket and it fit fine now and before. Bodyman bought new windshield and used my 5 year old, new in package rubber gasket to install. I noticed that the gasket did not set flush with winshield frame on either side post. Top and botom seem to fit well. I pointed out the problem and we both messed with it for about 30 minutes, but no real improvement. I questioned him about the install, and he said he put rubber on the glass, put trim in the rubber and installed assembly into truck. That is the correct sequence, right ??? I know it will leak like crazy and must be fixed, could it be the glass (had made in Mexico sticker on it), or do I need a different rubber gasket ? Part number on package is supposed to be correct for 1968. Anything else to check ? What could the problem be ??
My bodyman (30 years experience) and I are both stumped (and want to get this finished) HELP !!!!

BTW truck looks awesome.........will post pics when I get it back, Thanks

[Jwill41]

I am not sure but it seems to me that the trim would go in last

[Smitty]

The stainless that surrounds the glass can be different. The leg of the extrusion for lack of a better word that fits into the rubber molding differs
in some of the later years. So it could be that the gasket is wrong. Ran into this problem with my brothers '71 and an aftermarket rubber. Went to chevrolet a little more expensive, but they had the right application to the year rubber!

[BAD4X4]

There is a short lip moulding and a long lip. All the new aftermarket moulding should take both. I know this because my buddys dad owns a classic auto glass shop. Hope this helps.

[Green Machine]

Lmc lists two different numbers 67-70, and 71-72, I have the correct number, atleast on the package. I don't think that is the problem as the trim sits in there ok, but I could be wrong, what would the symtoms be if you tried to put 68 trim in a 71-72 rubber ? any thoughts appreciated.

[71HUGGER396]

I just had new front glass put in my truck at a shop. It take 4 guys, four hours. Big pain in the butt, glad I didn't do it at home.

[Robert1970C20rstbukt]

The 67-70 trim is shorter than the 71-72 trim, just so it makes more sense. If you try to put the short trim in the deep gasket, you should be able to just pull the trim out I'd think, but I'm not a windshield guy so I have no idea.

[Green Machine]

Yep, and if you had 71-72 trim in 67-70 gasket, it would stick way out. I dont think that is the prob. Has anyone got a bad gasket or funky windshield before ? Who besides GM, what board vendors might have a tried and true gasket for that ? Or do I just have to pull the sh1t out of it towards the inside to get it to hook ?

[72MARIO]

I have heard that it's possible to streach the gaskets out. The truck shop I deal with had a complaint from a glass shop because the gasket was to big. He simply sent him a new one and told the glass guy he streached it out. Not sure if that helps you out any.

[71RestoRod]

I'll relate my latest windshield install experience...

I had a local shop come to my house to do the install. I adamantly suggested that they send one of their most experienced guys to do the install, not someone that only knows how to work a caulk gun. Some kid shows up by himself. Of course he brought their standard replacement windshield (made in China or some such thing...) I helped him for three or four hours and there was just no way that windshield would go in. I didn't know if it was because he didn't know what he was doing or if it was the gasket or what (also an LMC gasket purchased several years ago). He left with the windshield half installed...

I was ordering a couple of parts from Rick's that week anyway, so I asked Shawn to throw in a new gasket (sorry, can't remember the manufacturer). The installation shop came back a week later. Go figure, this time two guys showed up with a nice quality PPG windshield. This one with the new gasket went in like butter. In my case, I know it was a combination of the crappy glass and LMC rubber, but I suspect it was mostly the glass. Dimensionally, it just wouldn't clear the windshield flange with the gasket in place. I had cleaned up (ground down) the flange really well too.

You absolutely need to set the trim before installing the windshield. Also, don't just rope it from the bottom all around to the top... you want to work your way out to the top corners or you'll get wrinkles.

Here's a good link with some tips:

http://67-72chevytrucks.com/vboard/s....php3?p=954930

[Green Machine]

Thanks 71RestoRod, would you care to elaborate on just what didn't fit where ? I don't quite understand yet. Did you happen to examine the gaskets and see any difference ? Thanks

Dimensionally, it just wouldn't clear the windshield flange with the gasket in place. I had cleaned up (ground down) the flange really well too.

[jostrans68]

I had mine put in a week ago By a board member that works for a local glass co.. I had a seal I purchased from Wes about 4 yrs ago... he showed up by himself i was concerned except fot the fact he owns one of these trucks...it took hmi about 30 minutes and it was done...Mine had no trim though....

[71RestoRod]

Originally Posted by Green Machine

Thanks 71RestoRod, would you care to elaborate on just what didn't fit where ? I don't quite understand yet. Did you happen to examine the gaskets and see any difference ? Thanks

I did inspect the gaskets closely. I couldn't see any difference as far as the shape goes, but the new one did have a better "feel" to it, being more pliable.

It seemed to me that the windshield was just too large all around. We tried seating it from the top and roping down, and seating at the bottom and roping up... nothing really worked, but it was so so close. It was very frustrating. The gasket would deform so much while setting the glass that the trim would just pop out.

When you install the windshield, you have to "slap" it to get it seated completely. As you slap, the gasket sort of rolls into place around the flange on the windshield frame. It was as if either the glass was too big to allow the gasket to seat into place (rolling around the frame), or the gasket was too big. The gasket is rubber and gives... so I'm of the opinion that it was the windshield that was causing the trouble. Apparently, so did the installer, given that they returned with a much better quality windshield. I had the first glass sitting there for over a week. With the cheap glass, it looked to me like I could see flat spots and distortion. Looking through the PPG glass is like there is nothing there at all. I probably would have reused the LMC gasket, but the installer had ripped it in a couple of places while trying to force it in. After the first fiasco, I just wanted a fresh start because the new trim was starting to take a beating.

As far as cleaning up the flange around the frame, there were places where the factory pinch points were kind of sloppy. When I did the body work on the truck, I cleaned up the windshield frame really well and evened out any protrusions and rough spots where the gasket sits.

[1-PU70]

There are only 2 mfg of gaskets to use GM and Precision. Anythin else and your just wasting your time.

[chickenwing]

Use "Precision" brand gaskets. Trim goes in then gasket then rope. Use masking tape to hold the whole shebang together. Install. I went from bottom to top. working evenly one side to other. then remove tape.

Pinch weld comment is accurate observation. I did not grind my defects down and the gasket over it was not as pretty as everywhere else. Was not so bad that it leaked. It is not so noticible now that the weather has turned hot.

[rickspickuppart]

Originally Posted by 71RestoRod

I was ordering a couple of parts from Rick's that week anyway, so I asked Shawn to throw in a new gasket (sorry, can't remember the manufacturer).

The seal was made by precision, a few years ago we had some problems getting other brands to fit correctly but then we started using precision's stuff we havent had any problems since.

Shawn

[Maximum Overdrive]

If you have the old windshield still, measure it and compare it to the new windshield.

[70c10]

I can also vouch for the PPG glass because my 70' has it. When my dad had his windshield done, they used a no name glass and an aftermarket gasket that wrinkled up in the inside corners. Recently I had a windshield place install a new windhield in my 71' but I reused a GM gasket I had and it turned out much nicer.