Funky Light Throttle Upshifts

[Nater_Potater]

My recently aquired '01 GT 4.6 works wonderfully in all aspects except during light accelerations in the 3-4 (I think...) upshifts. Around 35 mph/2100 rpm, as it initiates the upshift, it almost acts as if it unloads/uncouples (slight rpm jump), then quickly drops rpms down to around 1100. Since it's an AT, I really don't know what gear it's in during all of this. With a mildly brisk accel, this is less pronounced to where I can't detect it.
So, is this normal? Something to be concerned about? Noisy TPS?

Thanks for your input,
Nathan

 

[wmburns]

IMO you should think "lock up torque converter" is what you are feeling. Have you checked the AT fluid level and condition? What about the contents of the pan?

 

[Nater_Potater]

Tranny fluid good; no stinky. 54k miles. Too soon (too lazy?) to pull the pan. Just not sure what to expect from this car, as I just acquired it.

 

[squeak93]

I don't think it should lock the converter that soon. If it does it should be almost un noticeable. If you manually turn OD on/off and let it shift in at a higher rpm/mph, does it do the same?

 

[Nater_Potater]

If you manually turn OD on/off and let it shift in at a higher rpm/mph, does it do the same?

Good question; I'll try that on the way home this evening.

Nathan

 

[Neuron]

First thing I do upon starting is push the button and turn off the OD, around town and anytime below 50-55MPH for any distance. I don't like all of the unlocking and shifting even though its normal(test drove many while the 8 1/2 month search went on). I think the tranny will last longer too but could be wrong.

 

[squeak93]

Agreed on OD off unless doing 55+. My "auto" is a full manual valve body with manual control of the OD and Tq lockup functions. OD first, then lock the converter. Only above 55. Works like a charm.

 

[Nater_Potater]

Squeak/Neuron, you were right to question the lockup; that's the funky up shift I feel. Back in the day, the great 727 Dodge transmission would uncouple one gear before engaging the next during very light throttle input to avoid stalling the engine. If your "kickdown" linkage wasn't adjusted right, it'd feel as if you were doing a neutral-drop each shift change. That's almost what I sense during lockup. I like the idea of locking out the OD until building speed, so we'll go that route from now on. Thanks for everyone's help!
Nathan