Originally Posted by 04DSGMike
ok honestly i must ask, whats up with everyone saying you have to break gears in?? Never heard of that, i had my 98 Cobra swapped over to 4.30s and ran that ***** hard right when i left the shop...never had 1 single problem, not even a single noise from the rear either. Hell the shop owner told me to do that, cuz he said everyone saying you have to break gears in are full of ****. He said he also tells every customer the same exact thing and has never had a customer come back.
Im just asking, cuz i really dont know and from my little experience, they didnt need to be broken in.
New gears are strong yes, but they are britle when new. When the gears are new, the teeth are totally flat and when they're broken in, it wears a groove into the teeth, that's why they're setup a little tighter than spec before break-in. During break-in, gears get HOT. Heat is what kills gears. That's why an installer will tell you to drive it for 1-2 hours and park it overnight. Take it easy the first few days while she's going through her cycle. You can actually feel the meshing going "tiktoktiktok" at very low speeds when they're brand spankin' new. The heat of break-in also contaminates the fluid, so fluid change is suggested 300-500 miles after install.
I go by what my gear installer suggests after being in the business for over 30 years. I also go by what my manufacturer suggests...Yukon.