Hi folks, 03 Neon with just over 90k miles just developed another annoyance. Now, while in Drive and coming down from 3rd & 4th gear it's slipping/clunking from 2nd to 1st at 20-25 mph. This does not occur coming from 3rd to 1st or 2nd to 1st. Also, driving shifted down to 3rd stops the problem. My guess is it could be the solenoid again (replaced several years ago) or low on fluid. It looked low and I added some but the problem is still happening. Any thoughts?

 

Has the filter & fluid ever been changed?

 

Has the tranny filter & fluid ever been changed?

 

Yes indeed, a few years ago, full flush, new filter and gasket.

 

Ok that's good feedback, so it's had a full fluid flush & filter change, so not likely a gum, varnish, sludge problem, if the old fluid wasn't degraded at the service time..
A tranny is a closed loop system, so doesn't consume fluid like a engine, so any idea why the fluid came to be low? If it was low enough for the tranny pump so suck air, that could cause mischief, as the pump won't like trying to pressurize aerated fluid nor will the solenoids like trying to control things with aerated fluid. If we think of aerated fluid as a spring, rather than a solid, trying to move things in a pressurized hydraulic system, then we can visualize how aerated fluid could corrupt its action.