4l60e Shifts out of fist Under Load Immediately!!

Had trans rebuilt and if left in D or OD it shifts out fine. Hold it in first for a burn out or when racing from a roll and it hits 2nd as soon as you stab it no matter the rpms. Does anyone have any ideas??

Trans is getting REBUILT AGAIN! Pump rotar came apart. So i'd like to see if we can get this back to normal.

Also if you have any parts you recommend replacing feel free to throw it out there. Already has smartshell, front 5 planet, 65e input shaft, clutch packs, vette 2nd, billet OD servo, .500 boost valve, valve body work, and blocked accumulators... so it shifts like a b!tch! Going to get springs back in those guys. lol Date nights are no fun hitting 2nd at 1500 rpm even witha 3200 stall. lol

Thanks!

The pcm calibration may or may not have the option to adjust that feature. If it does, your tuner can fix that.
This feature hasn't always been available.