Funky Light Throttle Upshifts

N

Nater_Potater

Member

Apr 21, 2017

38

12

18

Southwest Idaho

May 12, 2017

#1

• May 12, 2017

• #1

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

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

May 13, 2017

#2

• May 13, 2017

• #2

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?

 

N

Nater_Potater

Member

Apr 21, 2017

38

12

18

Southwest Idaho

May 15, 2017

#3

• May 15, 2017

• #3

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

15 Year Member

Jun 2, 2005

2,260

362

164

Joplin, Missouri

May 15, 2017

#4

• May 15, 2017

• #4

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?

 

N

Nater_Potater

Member

Apr 21, 2017

38

12

18

Southwest Idaho

May 15, 2017

#5

• May 15, 2017

• #5

squeak93 said:

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

Click to expand...

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

Nathan

 

Neuron

5 Year Member

Nov 6, 2016

859

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93

May 15, 2017

#6

• May 15, 2017

• #6

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

15 Year Member

Jun 2, 2005

2,260

362

164

Joplin, Missouri

May 16, 2017

#7

• May 16, 2017

• #7

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.

 

N

Nater_Potater

Member

Apr 21, 2017

38

12

18

Southwest Idaho

May 16, 2017

#8

• May 16, 2017

• #8

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