Why does my 1984 oldsmobile omega not downshift while hot?

Question

When Im driving my car it upshifts great, when I decelerate it stays in high gear and starts to jerk and stalls after stopping. When I start it back up and put it in gear it stalls like it is still in high gear. resantly when it would start doing this I would downshift manualy to first gear and it works. If i let it cool down for 20 min it drives fine till it gets hot. The car only has 89,000 miles on it ,never beat on what would cause this? When it first started this it only did it once or twice a month now it is all the time.

Answer 1

First thing you need to check, when hot and running, is the fluid level. One quart too low can create funny shift patterns. The other thing that you can check is the vacuum line that runs from the carburetor or throttle body or intake manifold to the transmission "regulator". SOme of the older models had a little vacum "tree" on the intake manifold and there were three different lines hooked up to this "tree". -I-

This little vacuum regulator is generally a lifetime forget about it piece or part. If the vacuum line or the small rubber line that is on either end of the steel line is letting air in because of a leak from wear and tear, you will have bad shifting problems.

Most of the vaccum lines are rubber and will eventually dry rot and crack and fall apart. However, because of the proximity of the vacuum line to an exhaust manifold on most cars, this vacuum line is steel with little rubber tubes on either end to connect to the aforementioned engine accessories. I have seen the steel lines wear through from where they were rubbing on something for many years.

If you don't find an easy fix like a vacuum line or low on fluid, then you should have it looked at by a transmission shop and decide whether it's time to swap the tranny or buy another one attached to a newer vehicle.

I know that AutoZone and some other auto parts stores sell complete rebuilt transmissions.

Answer 2

Torque converter lockup solenoid is not letting the fluid bleed back into transmission,in other words the torque converter is staying locked up when you shut it off the solenoid releases the pressure.It is reasonably cheap to fix,should be done at a trans shop,the trans oil pan needs to be removed and replace the solenoid.Or you can just unplug it,lift the hood stand in front of car look straight down at the trans you will see a plug that has 4 wires in it,I think the color of plug is Blue,unplug this connector,you just won't have overdrive.