My '98 SR5 4Runner, when coasting or letting off the gas, downshifts very roughly. When accelerating, and going up through the gears, the shifts are pretty clean. It seems as if the car is confused as to which gear to be in and it abruptly bumps going into different gears while driving.

My first thought was the transmission so I read a few threads in here and was concerned that when I added Lucas AT Slip Fluid to it, that I may have made the situation worse. Honestly, I don't think the condition has changed, though.

I was also suspect to think the problem may have been in differential, but I really don't know. I don't want to bring my car to a transmission place because I expect they'll immediately tell me to replace the transmission. I'm not convinced the problem is in the transmission- it's just odd that the problem generally occurs when downshifting, coasting or when I don't have my foot on the gas.

Would appreciate any help.