AMC Eagle Den Forum

The Shop => Transmission Shop => Topic started by: carguy87 on June 30, 2011, 10:27:03 AM

Title: Automatic Transmission Drag
Post by: carguy87 on June 30, 2011, 10:27:03 AM
I have a 3spd auto with the lockup torque converter in my Eagle and was wondering if there is a way to fix the engine drag I am experiencing. In all three gears, if you let off the gas, the engine free wheels just fine and drops speed, but once the torque converter locks up and you let your foot off the gas, it holds the engine to speed as it coasts down. Is there any adjustment to eliminate this?
Title: Re: Automatic Transmission Drag
Post by: txjeeptx on June 30, 2011, 10:45:55 AM
That sounds kind of like normal operation of an automatic transmission to me. They do not coast like a manual transmission car does when you let off the gas and hold in the clutch or shift into neutral. Any automatic trans car will have a bit of engine braking when you let off the gas, just like letting off the gas in a manual trans car and leaving it in gear. There is some slipping allowed by the auto trans torque converter, but not enough to allow for the engine to go to idle while the car coasts along.

If your torque converter is remaining locked up too long and making it difficult to stop the car without stalling the engine, then there probably is some sort of adjustment that can be made - look into it in a factory service manual.
Title: Re: Automatic Transmission Drag
Post by: BenM on July 01, 2011, 01:31:56 PM
You should check your kickdown. There needs to be a spring attached, and the adjustment should keep throttle pressure off the rod at idle. It's probably bone-dry too.

The lockup should disengage when you take your foot off the gas and reengage as you put your foot back on, and the kickdown controls that.

You're not idling really high, are you?
Title: Re: Automatic Transmission Drag
Post by: carguy87 on July 01, 2011, 06:14:50 PM
Fresh fluid, everything is great with the tranny.  I know it is suppose to drag, but I also know enough that the lock-up is suppose to un-lock when you release the pedal, and that is not happening.  So when going 55 at 2k rpm and I let off the gas, instead of dropping to around 1.6k rpm, it stays at 2k rpm as it gradualy slows the vehicle down.  Being how rare these transmission are, I didn't know if there was a solenoid or band adjustment that could be made to right that issue.  Neither of the transmissions I had in my AMC's had springs on the throttle control rod though, I'll have to try putting one on and see if that cures my whoes, will definitely help me on some gas mileage and reduce my brake wear a bit  having that fixed.