YEAH!

 

I do 30 miles driving @ 55mph, cool for one hour or longer...repeat until the gears have 500 miles on them, then drain and refill diffs. If you have locking hubs you won't need to worry about the front differential since it will see off-road use only.

 

Straight from Randy's Ring and Pinion:

All new gear sets require a break-in period to prevent damage from overheating. After driving the first 15 or 20 miles it is best to let the differential cool before proceeding. I recommend at least 500 miles before towing. I also recommend towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles. This may seem unnecessary but I have seen many differentials damaged from being loaded before the gear set was broken in.
I also recommend changing the gear oil after the first 500 miles. This will remove any metal particles or phosphorus coating that has come from the new gear set.

 

 

how important in changing the oil, i also just regeared, and im thinking of keeping the oil for 5000 kms.. what do you guys think?

 

Well you don't want little metal chips floating around in the oil and getting worked into any of the moving components. That will just cause more wear and tear.

 

So what is the difference between new gears and factory gears? You can drive on the highway, tow or whatever you want as soon as your Jeep rolls off the line.

 

My point exactly. The thing is, it's pretty much impossible to "overheat" new gears as long as you don't forget to put gear oil in. I mean really now, how many people are honestly easy on a new vehicle?

 

Is it ok to put synthetic oil in or should regular oil be used for the break-in period?

 

I am getting a set of 4.10s that already have 3300 miles on them, is the break in period still apply ?