Tranny break-in

[J-440]

Evening all. I've got a 727 Mopar auto tranny connected to a Gear Vendors 6-speed OD, new parts and converter, a deep sump pan, and 5 feet of lines going to a cooler. I've got the car on jackstands and need to break the tranny in. I start the car, put it in reverse, and the wheels start turning intermittently slow. Good sign right? Unfortunately, I can't stay in the garage too long as I'm running open exhaust and the fumes are killer. Just wondering how long it takes for the wheels to turn normally. I'm not too keen on the break-in procedure. Thanks again.

[J-440]

Oh yeah, the rear-end is new also. It's a Dana with 4.10 gears. I know tolerances are tight right now, but still wondering what's up. Thanks.

[Steve Chryssos]

You're basically trying to get the fluid circulating and put a little heat into the trans while on jack stands. With warm fluid, you can more accurately top off the trans. As it sounds like you cannot reach operating temp on jack stands, stop short of fully topping it off, but make sure there is fluid on the dipstick. Then take a short, easy drive to reach full operating temp and top off.