One thing that will cause problems real quick is over extending them under load
With rig still hooked up to truck..........run driven legs down until they chatter then STOP.
Measure 1 1/4" down on driven tube and mark it with RED spray paint.
When using legs to lift and you see the RED STOP..that is full travel
Over extending causes gears to slip, excessive amp draw on motor
And that old tired motor.......it did all the work before and now it can't keep up with new motor.
Power cables from battery to motors/switches should be same length also