Insulating the transmission tunnel

I would like to insulate the transmission tunnel of my MJ while the drivetrain is out. The factory undercoating is rather thin (at best), so I was seriously considering using a product such as Herculiner to coat the tunnel. Any first hand experience that can be shared? Thanks!

i have my MJ interior herculined, it doesn't help the sound or heat much at all. what was your main focus? sound or heat? if you herculined over some Dynamat (or equivalent, the actual Dynamat is overpriced) you would be able to reduce the sound a lot more.

As the Comanche goes back together, I'm looking to apply many of the vibration/sound deadening tricks that are in use today. The purpose of the undercoating is to add mass to the sheet metal, which, in turn, helps to reduce the harmonics that transfer through it. I'm also paying careful attention to the interior of the cab, which is what you're referring to. Herculiner seems to go on thicker than most spray on materials, which reduces the needed number of applications. I'm just trying to see if there's another product out there that I should consider.

Have you pulled the carpet? I would do a professional spray-on liner in the interior. Something like Rhino that can be applied up to a 1/4 inch thick, then add some carpeted floor mats with a heavy rubberized backing or cut your own. They can be removed when hosing out the interior and the cloth will help absorb some of the in-cab noise.

Herculiner on the bottom side may help some, but it won't be enough. I would think it's more cosmetics.

That's just about what I had in mind. The exterior of the tranny tunnel is just not that well protected in my opinion. The factory undercoating was really just a half-assed job, so I'm going to fix it. This is one of those jobs that is really easy to do with the drivetrain out, but a real bear with it installed.

yeah, my interior is herculined and I could really burn my ankle on the tranny tunnel if I tried. I honestly don't think some extra rubber coating is going to make much of a difference. I have been thinking about putting some actual heat shields on the underside of the tunnel...I'd be interested to hear of some experience...

Pat

I've got herc and fatmat on my tunnel (not underneath, as you're saying, but on the 'inside the cab' part..and it didn't do much heat wise, and prolly not a lot soundwise. didn't hurt, granted, but..rubber and carpet still the best bet. I won't say doing an undercoating won't help, just not a fix all... Tranny cooler helps some with the heat..for those who posted after you, with those problems. Now, instead of removing the fingerprints, just warm/hot to the touch.

Undercoating the tranny tunnel is just part of what I have in mind. I really just wanted to install radiant shields (reflective heat barriers), but didn't want to provide an area where rust could form under them (salt, I live in Florida). The factory undercoating was not well done, hence the original post. It seems Herculiner works in the tunnel area, so that answers my question. I'll let you know how it progresses. Thanks.