Need help ftting rear glass? 39 truck

[ActionYobbo]

I cant find any instructions or do’s and dont’s or anything. No information at all on the method of fitting the rear window in the cab of mg 1939 truck. I searched youtube and google but found nothing. Do I or should I use some type of liquid sealer to set the glass in so it wont leak?

[mcharley40]

Hello, Im by far no expert. I took my rear glass out to replace the gasket a couple years ago I installed the new gasket on the window and wrapped a 3/16 nylon cord in the body groove lubed it up with soap and water then pushed the window and gasket into the opening wiggling some of it in place then pulled the cord making the gasket make contact worked for me good luck

[325w]

Seen one glass guy use Go Joe hand cleaner to lube the rubber going. Lube the rubber after the glass is in the rubber. Rope cord and are a hose removing hook.

[ActionYobbo]

Originally Posted by mcharley40

Hello, Im by far no expert. I took my rear glass out to replace the gasket a couple years ago I installed the new gasket on the window and wrapped a 3/16 nylon cord in the body groove lubed it up with soap and water then pushed the window and gasket into the opening wiggling some of it in place then pulled the cord making the gasket make contact worked for me good luck

That works for 41 on but the 39 is inserted into a chanel from the inside. First picture shows the chanel the glass goes in. The piece with the screw hole is the trim piece thats also in the second photo. Second photo is the trim piece that holds the window in, the window and the glass run chanel to go around the glass

[Model51]

I believe the original method of installation relied on the window channel material to seal the back window opening. I don't have a good enough original to determine if there was rubber material attached to the window channel or if they just relied on the fabric of the window channel material.
To be safe I'd run a small bead of black RTV on the inside lip of the back of the window opening, then press in the window glass with the window channel and then lock it down with the garnish molding strip and screws. You can wipe off any extra RTV from the outside of the glass.
It's mostly up to what you think is best and there's really no wrong way to go, but a small bead of RTV might be best.

[Kube]

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Be careful with silicone sealers as many will attack the glass. Glass shops use special, IE dedicated to glass contact sealers.
There was no sealer from the factory, and I don't see any reason you'd need it now.
I use glass cleaner sprayed on liberally vs. soap. Soap will often bubble long after the installation has been completed. Glass cleaner will not...

[38bill]

The glass is set into a rubber gasket and then the interior trim holds it all in place.

https://bobdrake.com/search?type=pro...up+rear+window

[Kube]

Originally Posted by 38bill

The glass is set into a rubber gasket and then the interior trim holds it all in place.

https://bobdrake.com/search?type=pro...up+rear+window

Interior trim? Not certain what you are referring to.

[ActionYobbo]

Originally Posted by 38bill

The glass is set into a rubber gasket and then the interior trim holds it all in place.

https://bobdrake.com/search?type=pro...up+rear+window

Thank you.

[Lamar Wadsworth]

The interior trim piece is the same '35-'39. Drake and other suppliers sell the rubber channel by the foot. Cut it to fit, rubber cement on the ends with the seam at the top. Tightening the screws on the interior trim compresses the rubber channel to make a water-tight seal.

[38bill]

Originally Posted by Kube

Interior trim? Not certain what you are referring to.

Inside the cab there is a metal rear window surround trim that screws down and compresses the thin window glass gasket. This holds the glass in place on the '38 and '39 trucks. There is no metal flange like in the newer models. The glass and gasket more or less just fit up to the interior of the back window opening. Not really a great design as far as I'm concerned.

[Mart]

Edit: I replied below before seeing that the 39 is different to the 41.

I can offer some advice. I did this on my 41.

Don't use too much soapy stuff. My hands slipped and I dropped the glass and broke it.
Make sure there is something soft for the glass to land on if you do drop it.
A second pair of hands is very helpful.

I have a video that shows my misadventure. Do not watch if you are not prepared for strong language. That said, some have said this is the funniest video they have ever watched.

Mart.

It going ok:
https://youtu.be/_T4dXtPVg4Y

It going wrong:
https://youtu.be/boCoiHmcbOg

[Kube]

Originally Posted by 38bill

Inside the cab there is a metal rear window surround trim that screws down and compresses the thin window glass gasket. This holds the glass in place on the '38 and '39 trucks. There is no metal flange like in the newer models. The glass and gasket more or less just fit up to the interior of the back window opening. Not really a great design as far as I'm concerned.

Thank you for the explanation. I continue to learn and appreciate that.

[38bill]

Originally Posted by Kube

Thank you for the explanation. I continue to learn and appreciate that.

No problem, and thank you for all you have done to educate us old Ford lovers.

[51504bat]

Originally Posted by Kube

Be careful with silicone sealers as many will attack the glass. Glass shops use special, IE dedicated to glass contact sealers.
There was no sealer from the factory, and I don't see any reason you'd need it now.
I use glass cleaner sprayed on liberally vs. soap. Soap will often bubble long after the installation has been completed. Glass cleaner will not...

And never use WD40 to lubricate the rubber. Use only window cleaner. That's what the guy who sold me the windshield and door glass for my '39 p/u. All his advise regarding the install was spot on so I have no reason to doubt the WD40 warning.

[ActionYobbo]

For anyone who needs to know the rear window seal is ford part number B-704220
So now I know what rubber seal to use do I need to use some sealer like rtv between the metal and the rubber?

[Mart]

I heard not to use generic rtv, but a specific sealant for windows. Not sure where I read it, but it is available, not necessarily for automotive use.

[37 truck]

I would think urethane would be better, black like they now use to set windshields

[Kube]

Originally Posted by ActionYobbo

For anyone who needs to know the rear window seal is ford part number B-704220
So now I know what rubber seal to use do I need to use some sealer like rtv between the metal and the rubber?

Be very careful what type of sealer you choose to utilize. Many will delaminate the glass.
Glass shops use a sealer made specifically for glass.
You should not need a sealer; Ford didn't.