Hello all, I just had my 4:56 gears taken out and replaced with 3:73's. I used the special "thin-set" gears to be able to keep my Moroso Brute strength posi. What should I do for break-in? or in other words...when can I smoke the tires!! :Brow: Thanks Jerry 1972 GS Stage-one, Flame orange/black owned 20 years next month!!!!
Jerry, Just did this last year using Richmond gears. They recommend free wheeling for a few minutes, wheels jacked up, then 3-4 heat cycles (normal driving) over a period of a few days to allow the gears to harden properly. They have some tech articles on their web site. Here is another site with break in information. Did you get any information with the gear set? BREAK IN From Richmond tech article: Note the break in process for drag racing... A new ring and pinion installation, especially a high numeric ratio with new bearings, can cause an excessive heat buildup in the rear end and cause softening of the gear teeth and bearings if a break in is not performed. Street vehicles should be driven at normal street driving speed for approximately 10 miles, then stop and let cool for 30 minutes. Do this 2 to 3 times. Towing vehicles need approximately 200 to 300 miles of normal street driving before being used for towing. On circle track race cars make approximately 6 to 8 laps at slow speed, then let cool for 30 minutes. Make 6 to 8 more laps at slow speed, then 2 to 3 laps at full speed, then let cool again for 30 minutes. Drag cars need only an initial run-in since they are driven short distances and heat is not normally a problem with proper lube and backlash allowance. NOTE: If after the above break in is performed, overheating of the rear end is suspected, repeat the final portion of the break in procedures.
