Hi Scotty! I have a 1996 crown vic with 60,000 miles that was extremely well maintained. It runs and drives great but lately it will shutter slightly at hwy speeds under light throttle after an hour or so of driving. I've investigated this somewhat and have found its torque converter lockup oil pressure or oil quality problem. Common in high mileage later model crown vics with much more violent shaking and overdrive problems. Now apparently a trans oil change with mercon v that has friction modifier in it cures the problem which has been done twice by previous and original owner at approx 20 and 40 thousand miles. Now at 60 I'm wondering if I should just add some friction modifier as it seems to wear out because the oil looks, smells and feels real clean, they have some red trans lube stuff available just for torque shutter but I've heard limited slip diff additive/modifier is the same thing and have some of that. Should I try the snake oil additive or do a oil change? Or am I way off base? I really like that you give people the truth about the crap they build. Thanks.
20 and 40k is early for tranny service. Unless they did it because of age. 25 years old, how long ago was previous service? Ya never know really if it was done, or done correctly. Me I would do a fluid and filter change, No Flush, put in a bottle of Lucas Trans stabilizer and see how it does after a few days.
Thanks Thumpy! Ya the car was 12 years old the first dealer trans service, then again in 2016 at 42k it seems like every 20 k a tranny issue appears. Unless the old guy was extremely meticulous with maintenance because the car is almost immaculate and 25 years old.
Thanks I will try an additive first!
Definitely try an additive first. Torque converter stutter is common on those cars but usually only at higher mileage. Still, it would cost quite a bit to drop the transmission and take a look at it. If it has worked in the past, stick with an additive and see if it works again. You may get lucky.
