Guys, car is an 88 LB9 IROC with T5.

On hot summer days, after about 45 minutes to an hour of highway driving, the parking brake handle and the T5 shifter shaft get really hot to the touch. Is this coming from radiant heat from the exhaust intermediate pipe running nearby? Up through the floor pan?

It has been this way forever, just wondering.

 

Have you checked the transmission fluid? The manuals can get pretty hot since they don't have external coolers.

 

The T-5 itself generates relatively little heat. That's not where it's coming from.

It's the result of the air coming through the radiator flowing through the trans tunnel, but not fast enough.

Check your lower air dam. That's what separates the high pressure in front of the rad, from the low pressure behind it. If it's not effective enough for whatever reason (missing damaged, car sits too high, etc.) then the air flow through there will be too slow, and heat will build up underneath the whole car.

It's also partly due to the exhaust being close by there. If you dare, you can try wrapping the I-pipe. Better would be, having it coated, or getting a stainless one. Stainless, since its heat conductivity is so much lower than carbon steel, also helps keep the heat inside the pipe instead of radiating out all under there.

 

Yes, I just changed the oil in the T5 a couple months back, it is full of fresh oil. RP Synchromax.

 

Air dam is fine, if it wasn't she would be overheating on the highway.

So you think it is a combo of hot air coming out of the engine compartment plus close proximity of the exhaust. That is what I suspected as well. The thing is the parking brake lever and T5 shifter get really hot after a long drive. I mean really hot. I'd say approaching 50 °C.

 

Yup, that's what I think.

Even if the T-5 was getting hot internally somehow, it wouldn't heat up the parking brake handle. But the hot air all around in there will.

I'd suggest trying wrapping the exh first. See if it helps. Then even if you don't want to leave it that way since it'll rot the pipe about 10 times as fast, you'll know where to attack the problem.

Eeeeeeezy enough also, to make a more effective air dam than stock. Bolt a piece of aluminum angle in its place; bolt a piece of thick rubber like a 18-wheeler mud flap to that. You can make it a bit wider than stock if you want, and cut it taller so that it all but drags on the ground to get a good seal. That material is stout enough to hold its shape but flexible enough to withstand curbs and such. Might even make your motor run cooler.

 

Yes, I can see heat generated in the T5 conducting up the shifter shaft. But the parking brake handle, that thing is bolted to the floor by 2 bolts, so the floor plate must be getting pretty damn hot there on top of the drive shaft tunnel. At least the carpet isn't smoking!

The original air dam is working OK, it is not damaged. Engine stays cool at highway speed unless it is a 110 ° day and I'm on a long uphill grade, in which case the temps start climbing. It hit 220 once on a hot day by the time I got to the top of the hill. But as soon as I started down the far side, temps quickly dropped back down to 180 - 190.

 

At least not when you're looking, or maybe, only when you are too.

Seriously, try improving the air dam. Even if it seems largely OK as-is. It's one of those things that can be a real surprise. Especially if you use the A/C very much.