guppymech

iTrader: (7)

Do a google search for info on gear break-in. I know it's hard to wait for WOT but you need 500 mi before nailing it. I know others will say BS, but do you want to do it all over again if you ruin the gears by overheating them before they're broken in? Also avoid the highway initially, be conservative and you'll have a nice quiet and long lasting gearset.
Link from Randy's Ring and Pinion FAQ:

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.

LS1_Sean

iTrader: (1)

Stay off the free way as long as u can during break in. With the 4.10 it spins the **** out of the pinion.

Troy5061

iTrader: (19)

I did 4.10s in my ten bolt and while they are fun the pinion looks like it belongs in a matchbox car. I would go 3.73s max with the ten bolt. If your on the street it should be fine, I wouldn't put sticky tires on and go to the track though. While your rear is apart compare the 3.42 pinion to the 4.10