91 lincoln town car

91 lincoln town car seems to shift unexspectedly from 1st to second when taking off then starts chattering only when stop and then go???changed fluid and filter..

Please explain the "chattering". Also, when you say that it shifts unexpectedly, please post your problem. Is the shift RPM too low, too high, inconsistent? That will help with the diagnostics.

Please explain the "chattering". Also, when you say that it shifts unexpectedly, please post your problem. Is the shift RPM too low, too high, inconsistent? That will help with the diagnostics.

I know there are TSB's chec with a dealer.

i checked bulletins, only found 3-4 shift concern bulletins and one for slipping/no movement, nothing on 1- or 2-3 shift concerns.
sounds like the speed sensor may be at fault, have the transmission module scanned for any codes.

Speed sensor sounds like a possible problem. One thing I was curious about. What color was the trans. fluid? Did you just drop the pan and filter and replace a few quarts or did you also perfom a full flush on the system? You had mentioned that it doesn't do it when it is cold. It could be overheating due to a problem with the trans cooler. Did the fluid look like it had been burned?

it was old when i changed it.

any build up in pan?

Tom,

it was old when i changed it.

Did you change it or have a power flush done? For the future don't do any power flushes. Flushes are only good if you want to turn your car into a paper weight. A flush can render a car immobile, especially in reverse. Do a standard fluid and filter screen change every 40.000 miles.

you're at the point where the fluid pressures need to be checked as the car is driven. This wil take a good transmission shop. sounds like there is a leak somewhere which get worse when the transmission heats up.

Big Block,

Sorry, but I have to disagree that all trans flushes are bad for the car. I was a skeptic at first but have been using them (lots of them) for years and have never had any problems. There might be certain trans flush machines that have problems (for sure). I've seen some that were so quirky that they could mess up cars but with a good one I've seen no problems. I don't feel that the pan drop alone gets enough fluid out. I have also seen cases where the car ran fine until a pan & filter was dropped and then it lost prime and had trouble getting it back (or never got it back no matter what method was attempted) because of a weak pump. I also feel that if you have enough debris in a trans filter to stop it up, the filter itself is probably the least of your worries. I've seen flushes not only maintain transmissions but also fix all kind of shudder problems and things of that nature. A pan and filter drop is kind of like draining a third of your engine oil out and spinning on a new filter. Would you be happy with that if you took your car in for service and they called that an oil change?

tomcat4343, call around in your area to see if there ia a trans shop which will offer some kind of deal to diagnose your transmission problems. sometime they offer discounts or apply the fees for the diagnostic process to the repair bill if you allow them to fix the problem.

Let us know what happens.

Tom,

What progress have you made in resolving this. Do you still need our help?

Has the lincoln been diagnosed/repaired yet?