rearend gears

[gipperco]

So while talking to my Dad about the 904 vs 727 conversations that have been floating around he asked me another question to bring up to the masses of knowledge here at home. He has a 8 3/4 rearend in the Duster with a new Auburn posi unit with 4:10 Yukon gears. They recommend not driving the car hard for the first 500 miles for a break in period. This car is a strip car, how the heck do you break in a rearend for 500 miles in a bracket car?

 

[oldkimmer]

1/4 mile at a time..........jack up the rear, use stands, put in drive and let her go for 1/2 hr.........kim............blip the gas 1ce in a while...........

 

[BoredandStroked]

When me and a friend finished putting a Ford 9 inch in his Camaro and had to break it in we did the same thing Kim said. But about after 100miles of that it gets on your nerves. We shut her down and took her for a ride on the interstate going about 50-60mph between 12-4 AM. To this date after almost 2 years of racing a 454 with a 8 71 blower making roughly 900hp he hasnt had trouble with it,but plenty with the powerglide in it.

 

[1qwikScamp]

i have a yukon 3.91 all you have to do is drive it enough for the gear to build up some heat and then let it cool down if it was set up corretly and had a good pattern you will be fine i have thrashed mine relentlessly and no trouble