1990 Automatic Tranny Problem
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 885
Likes: 1
From: Campbell New York
1990 Automatic Tranny Problem
The car's transmission stutters slightly but continuously when it is running at below 1800 rpms in overdrive. What is causing this? If we drop down a gear and the rpms go up it runs smooth. The car has 80,000 miles on it and was not abused.
I am looking at what my options are for fixing this based on your opinions. It is my wife's car so it is a cruiser not a racer. Thanks!
I am looking at what my options are for fixing this based on your opinions. It is my wife's car so it is a cruiser not a racer. Thanks!
Pro
Joined: Jun 2008
Posts: 610
Likes: 1
That could be the converter clutch going bad. Get it doing it and lightly tap the brake pedal to release the converter lockup. If it stops momentarily , you need a new torque converter. If it is indeed coming from the transmission it could be rebuild time 
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I agree with the above. Sometimes a slipping converter will chatter. Does it do this during acceleration or a constant speeds?
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 885
Likes: 1
From: Campbell New York
The chattering is very minor but noticeable at constant speeds. It is fine when it is accelerating. It will be a few days till the rains stops here to test out the brakes on it while it chatters.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Normally a torque converter will slip or chatter if under some load. At a constant speed, there is very little torque on the converter clutch to cause it to slip. Let us know when the rain stops.
Instructor
Joined: Jan 2007
Posts: 175
Likes: 1
From: Ocala FL
I just picked up a 90 the other day and mine seems to do the same thing. If I am running 55 -65 around 1800 - 1900 rpm it shakes alittle with lite gas. If I step on it and get above 2000 it is fine and the car shifts smooth. Any thoughts? The car only has 30k on it.
