Toyota Celica transmission woe

I have a 1992 Toyota Celica with automatic transmission and 55,000 miles. About once a week I’ll be driving down the road, feel a slight shudder, watch the rpm’s shoot up, and lose drive. As if it’s in neutral. As I coast to the side of the road, at about walking pace, the car magically regains drive and I’m good for another week or so. The whole time I don’t touch or move anything. The dealer has flushed the tranny, but to no avail. Please tell me it’s not haunted!

Your mileage is extremely low for a 1992. My question is: do you live in a city and do lots of short distance driving, or do you simply not use your car very often and it sits for long periods?

The mileage is correct, as the car’s always been in the family since new. It’s been one of the kid’s college car for the past 4 years with no problems and therefore sees all types of driving conditions.

What did the dealer do besides flush it? Did they check anything - hook it up to any gizmos - give you any other information?

I know a minimal amount about transmission, but that kind of thing sounds to me like an electrical problem - a dirty plug/harness or ground or something.

I don’t really know, but they’ve always been on the ball, so I would assume that if something could be hooked up, they hooked it up.

The problem is it’s been a college car for the past four years haha. A Toyota Celica at college equals: late-night shenanigans such as revving the car in neutral and putting it in drive, attempted burnouts, lots of full throttle acceleration from every traffic light, and plenty of “ooh let me drive” friends, among other things. This in combination with lots of sitting and probably infrequent transmission fluid changes has probably brought on some issues.

Speaking of having issues…

Have you checked the fluid level just to verify that it’s where it’s supposed to be?
If the fluid level is fine you might consider adding a can of Berryman B-12 Chemtool (avail. at auto parts houses or even Wal Mart) to the transmission fluid.
Rubber parts in the transmission are about 17 years old now and rubber hardens as it ages so the B-12 may help soften things up or loosen up a sticky valve or govenor.

Over the years I’ve done this with about half a dozen automatics for several small used car dealers who did not want to get into the expense of ripping a transmission apart and it solved all of them except one if I remember correctly.
JMHO and hope that suggestion helps if you choose to try it. Chemtool is cheap and it sure won’t hurt.

This transmission is completely mechanical, except for the TCC signal. The problem sounds like a leak in the valve body, dropping pressure to the final drive clutches or a weak pump. Only a transmission shop can determine the problem and fix. These transmissions have various test ports to plug a pressure gauge into, and read line pressures through the different gears. Most dealerships don’t do transmission work, only fluid changes, and will out-source any transmission problems like this.

It sounds like I have a Plan A and a Plan B. Many thanks to those that replied!