New Rear Break In Procedures

[radioguy]

I can't seem to find a definitive answer on this question.



I have a freshly rebuilt 8.5 inch 3.42 posi out of a 71 Nova that I am putting into my 68 Bird.

Since the rear is brand new are there any particular break in procedures? for the gears? for the posi? I just don't want to screw it up after i get it in.

Doug

[andrewb70]

I do think that gears require a break in. What brand of gears? You may want to check with the manufacturer of the gears for a proper break in proceedure. I suspect 500 "normal" miles should do the trick.

Andrew

[chicane67]

The perfered method:

6 to 7 heat cycles should do for initial break in and then drive it like Grandma for another 500 miles.

A heat cycle consists of driving on the freeway for 15 to 20+ minutes to heat it up and then stopping and letting the entire differential cool down to ambient temperature before the next cycle was initiated.

So, if you drive to work at a near constant speed or average more than 50mph for 15 to 20+ minutes...... and then drive it home the same after work, you could accomplish this in three to four days.

.....And then drive it like Grandma for the next 500 or so miles.

[radioguy]

Thanks guys. I had really hoped that I could just get in and burn rubber... and it would be two marks now instead of just one.

I'll take it easy, do the heat cycles and drive like grandma. My wife thinks I drive like her anyway. I do except when she's not in the car with me.

Doug