[gointodeepwater]

Took my 2001 Mercury Sable to the local shop and let him drive it. My car would sometimes drive ok but on occassion would surge or shutter. I would watch the RPMs change and it looked like the transmission may be trying to shift in and out of overdrive or even an ignition or fuel problem. I did the cheaper stuff first. Replaced fuel filter - No change. Replaced Spark Plugs - No change. Replaced Plug Wires - No change. My mechanic road tested it and he thought it was the Torque Converter. I asked how much it would cost and he said maybe $6.00. When we got back at the shop he brought a tube of Dr. Tranny Instant Shudder Fixx and put it in the transmission stick tube. Within 1 mile of driving the shutter was gone.