transmission shift

I noticed yesterday that my 02 Intrigue (180K) was behaving funny. At highway speeds, when lifting my foot off the gas pedal, it seemed like the transmission shifted to neutral - the RPMs dropped to idle and it would not shift back into gear until ~3000RPM. Everything shifts smoothly, but this seemed weird and out of normal. Any suggestions on what to look for are appreciated. I have performed no (ZERO) maintenance on the transmission.

sounds like tranny module or low on fluid. first thing i would do is change tranny fluid and filter and if you do that take a magnet in old fluid and see how many metal shavings or chunks of metal in it. you will find some shavings thats normal on the wear.

thanks for the quick response. I'll work onthe fluid and filter change this weekend and let everyone know the results.

I changed the transmission filter and fluid this weekend - what a mess. The really good news is that were no shavings/filings in the pan. Just a little residue on the magnet. The car is shifting much better, but still seems like it drops out of gear at high speeds when you let up on the gas pedal, although not as noticeable as before. You mentioned a module that may need to be replaced. Where is it located and what do you think it costs to replace? How difficult is it to get to?

I doubt that the PCM (which controls the shift solenoids) needs to be replaced. If the "Check Engine" light is not on there may not be any stored DTCs for the transmission, but the light doesn't always turn on for transmission codes. A quick scan would reveal if anything is present, however. I'd expect a general trans performance (slip) code if anything.

The symptom could be casued by various minor problems, like the OD sprag unlocking on over-running (as it should) but perhaps not locking quickly once the engine speed ramps up again, or a TCC unlock/apply issue, or a low pressure line failing to lock the 4th clutch or TCC clutch on accel from coast.

Changing the fluid and filter was probably a good idea, even if well overdue. It's possible the symptoms will improve as the fresh fluid does more cleaning and possible that it will not improve. As long as there is no noticeable slipping on normal upshifts there is probably no real damage being done to friction surfaces. Pay close attention to the operation and consider changing the fluid and filter again in a few thousand miles of driving. You might be surprised at how dirty it is again, and cleaning may be the best thing you can do. I'd avoid any kind of flush or treatments in a bottle since slippage isn't likely the issue. Normal maintenance may solve it, if it isn't too late.

If you change the fluid again, consider removing the oil tubes and cleaning them out manually, and removing the accumulator cover and checking the seals, springs, and oil passages. You can find directions in various places, such as this site.