olmann

Makes sense the heat coming from the tunnel. My car is black on black without tinted windows. I have a properly working R12 system that I rarely turn above 2 fan speed or it will freeze me out! That is on 100 degree days. I never use the rear air.

dr bob

Insulation is great but it only slows the migration of heat.

The foam in the tunnel is supported by the torque tube. When new, it's soft enough to actually seal and insulate that area. Since it's supported by the torque tube, that seal in the tunnel is lost if [read: when] motor mounts and transmission mounts get tired and start to sag. Maintain engine and transmission mounts and you stand a much better chance of maintaining the seal.

Driving with windows down causes a slight pressure difference between inside and outside of the car. If the foam in the tunnel isn't sealing, you'll get hot air drawn into the car from underneath. So no AC and leaky tunnel foam can make the car even more of an oven on a hot day driving with windows down.

I'm not aware of a way to replace the foam with the torque tube still in place.

linderpat

Thanks Dr Bob. Records show that my torque tube was replaced as well as motor mounts a few years back. They (the shop that did the work) likely did not put a new seal in place and/or it cracked, broke or whatever. I will stuff some insulation around it from the top side (will need to remove the consol) and see how hat works.

PRC928

Regarding the heat from the tunnel, my folks had a 86 that had this issue and I sprayed some (did not need much) expanding foam into the opening below the shifter (it was an auto). It worked great and we did not need to drop the torque tube and replace the factory foam.

dr bob

Temptation might be to lower either the engine or the gearbox to drop the torque tube enough to stuff/fit a bit of the 3M Thinsulate that Blake mentions in post 9 above. You can get it easily, disguised as a camper's sleeping pad, at exotic camping equipment stores like Wal-Mart. Cuts with scissors or a razor knife, can be cut and even sculpted with an electric meat-carving knife from the garage kitchen.

Knowing how much fun it is to R&R the shifter and cable in my auto gearbox car, I'm not sure I'd haphazardly squirt spray foam in the cavity under the shift plate.