4l60 trans 4K yank SS car never did this until this last time I tore it apart and put it back together....it won't do it until I'm in lockup and when I'm letting off the gas it will start bouncing???? But soon as I tap the brakes it stops???? Fluid is kinda low so I've been adding very little don't wanna overfill...car isn't tuned yet it's a heads cam car

 

When applying the break pedal it unlocks the converter.

With a aftermarket converter you will get that bucking when the converter locks up at to low rpm. That can be fixed in your tune.

Like with mine I do not have my converter to lock up at all except in 4th gear above 40 mph

 

yeah seems the trans is all outta wack.... and a lot of ppl have been telling me leave the converter unlocked

 

The converter locking at low rpms is lugging the motor. Kinda like in a manual when your in to high of a gear at to low of a speed, it gets jerky.

You want the converter to lock for highway driving but get a good transmission cooler and have your converter set to lock in OD only above say 40-45 mph.

 

got the biggest cooler I can find....yea it's locking up around 35 40 mph and bogging the car down needs to be set for like 45 50 if my tunner can set it to around 45 50 I wouldn't mind it but if he can't I'll have him leave it unlocked