Auto trans seems sluggish

[VitaminCRR]

I have been driving my 69 RR 383/727 car for almost two years now and I feel like the trans might be loose or slipping. When I put it in drive or reverse it just kind of slides into gear, as opposed to a solid (I don't want to say clunk, but I will) clunk. I can rev the engine up and it takes a few seconds for the car to move. It seems to get better as it warms up but it's still not real crisp. I can barely turn the tires over from a stop. Does this sound like a bad converter or something else in the trans?

 

[R413]

Are you checking the fluid with engine running in neutral at curb idle speed?

Sounds like low fluid or restricted filter. May need to remove pan and replace the filter and see how much debris is in the pan.

May need to start it in neutral for a minute before driving off and see of it changes.
Fluid doesn’t circulate in park so that’s why it needs level checked in neutral.

Tell us any history on this trans. Overheated, Run low on fluid? Abused?

 

[turbine68rt]

Fluid doesn’t circulate in park so that’s why it needs level checked in neutral.

Fluid is being pumped whenever the torque converter is spinning. The line psi is lower in park than neutral. 0-30 in P and 50+ in N.

 

[Fran Blacker]

Kick down (throttle pressure control) linkage adjusted right?

 

[peabodyracin]

I'd do a fluid/filter change 1st thing. Most of the time that's cured the problem for me. When doing it check the converter to see if there's a drain on it.

 

[R413]

Kick down (throttle pressure control) linkage adjusted right?

True, if it is not giving enough throttle pressure then it will burn up the trans. Maybe it reached that point.

we need more info on this.

 

[dvw]

Do you have to rev the motor from every stop? How are the shifts themselves? Does the engine flare on the shift? Not spinning the tires from a standstill could be engine combo, age, tune, converter. is the engine stock? Where is the ignition timing? But a stock well tuned 383 Road runner should easily break the tires loose from a stop.
Doug

 

[VitaminCRR]

Kick down (throttle pressure control) linkage adjusted right?

Don't know. I assume that's something I can find in the FSM.

Do you have to rev the motor from every stop? How are the shifts themselves? Does the engine flare on the shift? Not spinning the tires from a standstill could be engine combo, age, tune, converter. is the engine stock? Where is the ignition timing? But a stock well tuned 383 Road runner should easily break the tires loose from a stop.
Doug

Don't have to rev the engine as much after it warms up. 1st to 2nd and 2nd to 3rd shifts seem OK when in normal driving mode, just a little sluggish off the line. Engine is stock except for Pertronix ignition. Timing is set correctly. Wondering if the engine is just a dog.

 

[dvw]

Its possible the stators overrunning clutch isn't holding. If that were the case the converter wouldn't multiply torque. Also possible the filter is plugged or the cooler circuit is restricted. Take a good look at the cooler lines and make sure they are not kinked. If both those show good? Not knowing what the combination is, could be some cheapy quick rebuild converter, could be a low compression worn motor. The next thing I would do is a compression check.
Doug