I just got a set of 4:10 gears installed.

They dont whine or anything,and I put about 25 or so miles on them of highway driving.

Do I have to do any more break in than that?

 

Heck no, let her rip.

 

The guy who installed mine, pulled it out on the street and left 100' of rubber marks. He had to make sure the posi was kicking in.

Then he drove it in traffic to the expressway and then up (and over) 100mph to check for vibration.

 

Scroll to page 13:

http://www.ring-pinion.com/downloads/yukoninstman.pdf

 

Here's what the shop said that did mine on my 8.8 on my Mustang.... take short trips for the first 100 or so miles, then run it for about 500 miles normally, change the oil, and then you are free to beat the heck out of them. This is GREAT advice from the best Ring&Pinion guy in the Central Valley in California. If you dont wear it in, the hardened surfaces become brittle and then you are more prone to shattering them. Trust me, this guy knows what hes talking about!! It worked great on my 8.8 in my Stang. Also, an old time racer named Smokey Yunik has a complete article on WHY you break your gears in before jumping on it. The man is a legend and I listen to everything he says. Be easy on them for a few hundred miles at least and you will be ok.

 

i do ring and pinions pretty regular, just finished up a dodge 2500 with dana 60 front and rear, this is what i always recomend and what was recomended to me, first 500 miles do not get on it to much and try to vary speed to get a even wear pattern, after 500-1000 miles change fluid and you are ready to thrash em, this is what i recomend for any vehicle that has a new ring and pinion