Help: Hot transmission tunnel (1 Viewer)

[WCBlueSky]

Driving at 70 MPH today with an outside temperature of ~95 deg F, I measured 140 deg F under the carpet of the transmission tunnel on the passenger side. On top of the carpet is 100+ deg, which makes it uncomfortable to sit in the passenger seat. This seems crazy to me--there should be a ton of air flow at 70 MPH. I measued exhaust back pressure in one of the O2 sensor holes and it was basically zero, so I don't think the cats are plugged. Any insights?

 

[JunkCrzr89]

What’s yer trans temp?

 

[WCBlueSky]

I don't have a gauge so not sure. The coolant temperature is fine though.

 

[Road Apple]

Just installed multiple layers over the interior of the truck. I started with a layer of Aluminum heat shielding over the transmission tunnel area, bought off of Amazon. I added a layer of Kilmat 50 mil and a layer of Noice Red 150 mil over the enter cabin.

We’ve been driving this week through Arizona and Utah with temps in the 90’s. The transmission tunnel is fairly cool on the sides near driver and passenger legs, but pretty warm over the center console/shifter area, where is difficult to apply shielding.

Big improvement overall. The family is comfortable and so is the dog on the floor.

 

[Woofythewolf]

Are the front wheelwell rubbers in place? They'll keep more air moving backwards rather than getting sucked out the side.

Otherwise I'd have to check mine but that sounds kind of normal, it does get pretty hot with how inefficient our trans is.

 

[BILT4ME]

More to do with cat location than anything.

 

[spearmunch]

I've had the same problem. Check under the console around the transfer case shifter. I had a small gap under the plate surrounding the transfer case shifter, and after tightening it down then problem seems to be resolved. I would check there.

 

[Bambusiero]

isn't most of that air-flow around the engine and through the transmission tunnel - heated radiator exhaust? So - that air is typically heated to 186 F (or so) under normal operation, right? It's just normal - nothing is wrong. All you can do is insulate the tunnel better inside.

 

[mudgudgeon]

Adding thermal insulation to the floor can make a big difference. Figuring out how to insulate around the shifter holes is critical.

 

[cybrstar]

I removed my rear heater and there is a hole in the floor where the coolant tubes come into the cab. A rubber padding surrounds the tube and from its condition was completely deteriorated and brittle. Location was located right on top of the exhaust bend. Slightest holes in that padding will cause very hot conditions in that area as well.

 

[elhombre]

Just installed multiple layers over the interior of the truck. I started with a layer of Aluminum heat shielding over the transmission tunnel area, bought off of Amazon. I added a layer of Kilmat 50 mil and a layer of Noice Red 150 mil over the enter cabin.

We’ve been driving this week through Arizona and Utah with temps in the 90’s. The transmission tunnel is fairly cool on the sides near driver and passenger legs, but pretty warm over the center console/shifter area, where is difficult to apply shielding.

Big improvement overall. The family is comfortable and so is the dog on the floor.

View attachment 2745305

Gonna do this soon myself too. Can you list the amount of insulation you bought? Thanks

 

[Road Apple]

Gonna do this soon myself too. Can you list the amount of insulation you bought? Thanks

The heat shielding from Amazon was minimal. I’d would double this and extend it further away from the transmission tunnel if I did it again.

Brand: CaliBikerClub

Aluminum Heat Shield Protection with Fiberglass and Self-Adhesive Backing Heat Barrier (1 Sq Foot)​

2 boxes of the Noice RED 150mm 36 sq ft was enough to finish the main cabin, but wouldn’t finish the doors.

Same for 2 boxes of the Kilmat 50 mil 50 sq ft. I needed a bit more to finish the doors.

I used every scrap to cut and paste into the nooks and crannies, especially around the shifter. That’s where a lot of heat and noise escapes into the cabin. The doors are worth the effort. The quarter panels take some time and patience to cover.

 

[Mrtwooooo]

years ago I added a layer of mass loaded vinyl that had a radiant on one side to the passenger side footwell and the transmission tunnel and it made quite a big difference. Some better insulation other than a radiant barrier should make more of a difference.

 

[John Young]

I think something is up with our 1993 Middle East 80, El Wahsh. Yesterday while after driving on the highway for 30 minutes or so I noted that it was quite warm on my right leg. I reached down and found the brake lever uncomfortably hot and the whole area around the center console and fridge was very warm. My first thought was that there was a hole in the muffler and hot exhaust was hitting the underside. But I crawled underneath today and could find no exhaust holes. I did note that the insulation on the freon lines had melted. So something is not right.

It looks recent too.

Here are some more photos.

I don't see any signs of overheating on the transmission itself.

The only thing I can think of is that the u-joint is on its way out and is getting very, very hot, but it would have to be red hot to melt the insulation. It makes no noise either.

The trans itself seems normal temp in operation. It is just the very tail end that got hot.

Any theories would be most welcome.

 

[Jorgito]

Reviving the old thread as I am having the same issue, not sure if the fact that I run 1hd-fte which might have higher temps on the exhaust then 1fz-fe ( not sure just guessing ) would be the culprit. I need to wrap the underside of the passenger seat with something similar to this: Floor & Tunnel Shield II™ - 10" x 10" - https://www.designengineering.com/floor-tunnel-shield-ii-10-x-10/