Silicone Gaskets

[GMCGoat]

I've got some leaks.

1. Transmission fluid pan
2. Rear differential.

I'm thinking about using silicone for my gaskets fro tranny and rear diff and wnat to know which colour to use. There is blue, red, and black.

Any help would be appreciated.

[mknittle]

red is high temp.

[Rufton]

Ultra rtv is my favorite and Versachem is my 2nd choice; they seem to have more body.
I don't sweat the color unless used near exhaust.
I buy rtv in larger calk cartridge due to $/oz and convenience.
I check the specs.
For example:Versachem black is good to 535F.
Good idea to verify O2 sensor safe if using on engine.
I've recently started using RTV w/o gasket in some applications w/ good success.
RTV looses setting ability if to old; I take the time to verify dab of rtv will set if not fresh.
Old shelf life expired non setting RTV comes in handy for some applications.