...in the cavernous area at the back of the cab. I would stuff butyl vibration dampening material but the adhesive back that would be needed to keep the stuff up in there won't allow me to stuff it up there. I could spray a foam insulation in there but I fear a moisture build up. I don’t what is best and wonder if anyone here has figured it out and got it done. I have used Second Skin dampening all over the cab and bedliner under the cab but that one area can sure create a tin can sound.
I wish I could help you with this, but I have my tank behind the seat. If that wasn't the case, I think I try some carpet (like out of a house) and then put some really nice speaker boxes back there to hold the carpet down. If you mean along the vertical back of the cab, sounds like a job for Hush Mat? Good luck! Maybe pictures would help others come up with ideas?
The picture link is below. It is the area around the rear window. It is about 2" clearence and would be difficult if not impossible to put any vibration dampner up there. I'm open to any suggestion. I've thought about some kind of foam but I'm afraid of moisture buildup there with foam. http://s729.photobucket.com/albums/ww296/BIGCHEVY3600/?action=view¤t=PA140346.jpg
I would spray foam it, It would be the least moisture inducing of most anything else you could cram down there.
