2004-2007 Cadillac CTS-V General Discussion Discussion, Heat Wrap, on exhaust around the diff. in Cadillac CTS-V Series Forum - 2004 - 2007; I've seen some guys wrap the exhaust around the differential to help keep the heat off it.
I have a ...
I have considered doing this but have not gotten around to it.
I think this idea falls into the "well it can't hurt anything" category. It is possible that the exhausts contribute to the heat level of the differential, but there is no real evidence that the temperature of differential is too high unless you are tracking the car. I have checked the temperature of mine using an infra red thermometer after running at highway speeds for awhile in 100 F heat and it was not all that hot. Additionally, it is entirely possible that reports of heat wrap making the differential quieter may well be because the wrap acts a sound deadener for the exhaust resonation from a noisy differential.
Finally, I think one of largest contributors to these differentials becoming noisy is driving them hard when cold. This happens because the differential depends entirely on "splash" lubrication which is inefficient until the fluid gets warm - and that takes awhile. If you watch your water temp, oil temp, and transmission temp you will see that the engine oil and transmission take a lot longer that the coolant to get up to temperature. In fact, on a cold day it can take 20 miles to get the transmission up to temperature.
In any event, I may still wrap the exhaust with some header tape - it can't hurt.
Automobile(s): 2004 CTS-V Raven, StainlessWorks header back exhaust
There is quite a bit of airflow under the car, I would wager enough that the diff doesn't get hot from the exhaust unless the exhaust is touching the diff. Mine is a good inch or so away from the diff.