there are definately some things you should know regarding letting them cool. im sorry i cant be more help im sure someone will chime in about proper break in procedures. im curious as well ill be getting gears in a couple weeks

 

These are the instructions that came with my Yukon gears for the break-in (p. 18). My installer basically repeated what was in the instructions with special emphasis on avoiding heavy acceleration, no towing for the first 500 miles, and no long distance driving. He also recommended staying below 50 mph.

I'm about 200 miles into my new gears now. At 500 miles, he will do an inspection and replace the gear oil.

http://yukongear.com/Downloads/Manua...structions.pdf

 

Resurrecting this old thread... useful information here!!