restoring a cab i recently picked up and need to remove the front glass to get it ready for the sandblasters. reason for the removal is that it has some surface rust behind the weather stripping
So it's not anywhere near new (otherwise no rust) so the gasket is likely dried and perhaps a bit cracked.
The most important part is the glass (Important =$$) I'd call the local JD dealer first and see if the gasket is available and right then and there order it. Then (and this is very important) WAIT for it to come in and compare the two to be dead certain
that they are the same or at least interchange.
Method #1 (of 2)
Since you now have a replacement, take a sheet rock knife and carefully cut the old gasket out.
Spray the rubber in front of the cut with soapy water and make several cuts to make a cut deep enough to be effective.
Here is where you will most likely want two people (you and someone else). You've now cut the gasket but it's still stuck in the frame. Pull the cutoff part away from the frame ( I would have cut two continuous sides at least ie top and a side). Some where in/near this time you might like to warm
the gasket with a heat gun. You've now exposed more of the frame, press gently to flex the gasket away from the cut side (if you cut the outside then push it inwards or vise versa). Use the other person to help catch the glass. If it doesn't come then cut more gasket or more deeply or cut on the glass side.
DON'T be in a hurry. It's a tedious process usually. Not always though.
Putting it back in is easy. Put silicone in the gasket channel for the glass to sit in (some sillycone - don't fill the gasket channel). Then on the gasket channel that's going to connect with the metal, put a goodly amount of silicone followed by clothesline rope/line. Press the glass and gasket assembly against the hole and frame. While someone is pressing against the glass, get on the other side of the glass, hold one end of the rope and with the other end pull firmly so that the lip of the gasket slides over the lip of the cab. Soapy water can help make things more slippery here too.
After you've done a couple it takes just about no time to do.
wear Nitrile gloves if not some thing tougher. Silicone gets to be messy. Have quite a few rags - again the silicone thing. Try to work over a sort of softer surface. If you have a carpet scrap a trashed movers mat or two some thing like that incase the unthinkable happens. Work in a heated area or during the summer. You want that gasket to be as flexible as possible, even if you're cutting it off completely. If you need to destroy the gasket because it won't flex enough then cut it so as to form a "V". That way it will hold the soapy water and allow the blade to move easier. About the soapy water - make it slippery like the Bubble Juice kids blow bubbles with or just go buy some at Mall-Wart/Mao-Mart.
About the silicone- the pros will use an adhesive usually. They have a relatively short pot life (versus your speed) and there's the likelyhood of getting some schmutz (technical term) on your new paint. Silicone will come off, with a struggle but it will come off. The adhesive is nearly bombproof. The Sheetrock knife Blades - buy heavy duty ones don't cheap out here and (this is really important) change them often. If they have been in use for 5 minutes or so swap them out. This work is murder on 'em.
You could buy a new gasket and deliver the cab and gasket to the local glass shop and point at things and make grunting noises. They'll understand. Bring your checkbook - though it might just be cheaper than you'd think. They can pull it and after it's treated and painted, they'll re-install the glass for you.
As always, your mileage may vary,
This process can involve a large amount of continuous force - exercise caution
-- Always remember that you are working with glass.
BE CAREFUL to walk away with all your personal parts. There are several ways to do this procedure, I've outlined two that I have used with success- there may be others. Wear all protective gear- safety glasses and cut proof gloves are a good place to start.
Sheet rock knives don't just break - they seem to explode under lateral forces be careful and Know your limits.
G'luck - hope this helps