I had a used 4L60E Tranny put in my 1999 K 1500 Suburban and when I take off it feels like I'm pulling a building than it BANGS hard going into gear. I changed the Shift Solenoids & TCC Solenoid along with Fluid & filter Kit . It seems ed to go away for a bit but is back. I switched to Auto 4WD and now it runs as smooth as a new one. Is this safe to keep it that way ???