Originally Posted by LS1EB
So I have been heavily involved in the off-road world for quite some time and have set up several ring & pinions for myself and friends. Whenever you do a setup you always change your diff oil after the first 500 miles because of all of the small shavings that occur during break in and seating the teeth. Same thing goes for building a motor, after the first few hundred miles you change the oil due to the bearing break-in and such. There is no mention of this anywhere in the manual, just the typical change intervals. Pardon me as this is my first new vehicle ever, but do they perform some sort of accelerated break in at the factory and change the oil there? I know itís kind of a newb question and I have searched and have found that the break-in oil changes are not necessary but just curious as to why?
_Technically_ We probably should. However, the ones that come from the factory are usually not machined to the tolerances of an aftermarket set. Having a bit more slop in them is not the end of the earth compared to a race truck.
The same could also be said about new transmissions (Or any lube point). But again, the tolerances they machine these too anticipate this when they are designed vs. An after-market gear set.