I just put in a motive gear set 4.56 in my 9.25 rear and was wondering how you guys break in gear sets ?

 

listen for any ringing or whining or clunking noises for about the first 5 or 10 miles, if that all checks out good,your done, drive it how you normally drive...

 

I thought that you needed to keep the speeds down and not run it for long periods at a stretch, for the first 500 miles.

 

This.

Then, change the fluid.

 

Do a search on this site or on google. There is a specific procedure for the first 500 miles. Follow it or it's almost guaranteed to whine.

 

So factory sets are broken in already?

 

Not really, but, there is a 'break in' procedure detailed in the owners manual. Which almost no one reads.....

 

I have heard before that most factory gear sets are 'robotically' broke in on a machine. I cannot confirm or deny as I don't know. But like hey you stated. There is a break in procedure in the owners manual as is there for the engine. Unless you buy a hellcat. Then just ***** to the walls everywhere!

 

Drive as normal, they are a lapped and matched set so with correct setup they are good to go. You don't change your diff fluid in your brand new car do you?

 

Axle's are pre-assembled and delivered as a sub-assembly to the vehicle assembly line.
As noted, they're matched and lapped sets... I believe the assembled axle is tested for friction and noise levels before delivery.