I bought my 83 6.2 back in July and have had absolutely no problems with this truck, I love it. Recently when leaving work it felt like the transmission slipped then the truck made a noise(the noise was similar to the noise a starter makes when it doesn't engage and just spins).. I put it back in the parking lot and got a ride home. I checked the fluid and it was low. Put in 2 quarts, the level seems good now and the noise continued. It seems to be happening only when I let off the gas, when it upshifts everything works fine. The transmission is 700r-4. The previous owner said he had a new trans put in back in march. I have had no previous issues with slippage or any noise of this type. Please help..