Transmission Error

I have always done most of my own vehicle maintenance, and the first time I serviced the transmission on our Chevy Astro-Van I was taken aback by the filter. After dropping the pan you simply pull the old filter straight down to remove it. You then have to pull the old retainer/ seal (circular object), install a new retainer/seal, cram the new filter up into the retainer/seal, reinstall the cleaned pan, and add the proper amount of transmission fluid. I had always assumed that the pan fit closely enough to the filter to keep it from working out of the retainer. I was wrong.

A couple weeks ago I noticed the transmission slipping a little, and it was slow to go into gear. I checked the transmission fluid, and it was way over full. That didn't quite compute, but I pumped out some fluid and then the van could not move at all. I dropped the transmission pan and the old filter came down with the pan. Luckily, with the filter disconnected, the fluid level was high enough for some to be picked up, but the torque converter was not being kept full. After I had pumped some out, no fluid could be picked up by the pump.

We drive on gravel, and we go over lots of washboards, so I will drop the pan again, take some careful measurements, and install a shim pack of flexible magnets under the filter to keep it in place.

Our previous vans were Fords, and the transmission filters on those cars were bolted on; they never came off. The next time we go new car shopping we will be looking for a better idea.