My truck has been having trouble shifting from 2 - 3, all shifts feel normal except for this one where it doesn't shift until 2700 or so rpms under gentle throttle. Most shifts are around 2k rpms if not under. I'm wondering if a shift kit would remedy this or if it's a sign the transmission is in the beginning stages of failure. Fluid/filter both flushed at 70k miles, now at 96k miles. Fluid is at proper level, not burned. Ideas?

 

Whats it do after it shifts?

 

Goes fine. It'll hang up, take a good 15 seconds at 2500 +/- rpms shifts and then goes like nothings wrong. It does it every time it's shifting from 2 - 3 though.

 

Do you have tuning through SC? or are you stock? Does it have a cel on or are there any codes stored?

There is a couple TSBs out for the powertrains.

 

Nothing for codes, just had it inspected which it can't pass with any codes stored in the computer. It is currently tuned but it does it with or without the tune. The programmer doesn't seem to do much with the shift patterns.

 

just a guess, but dont the transmissions shift based on throttle position (or at least partly throttle position)? Might try looking at the TPS. Dont know if you can clean them like the IAC or not, but could be worth a shot...

mine hangs up until i lift....sounds like a manual...but thats my shift schedule I have programmed.

 

The performance tune actually does quite a bit to shift patterns. Mine will hang at 2500 rpm under light/medium throttle but will shift just fine under a tad heavier foot. But as you said, it happens without the tune so there may be some other issue.

As far as I know, no one is happy with the way our trucks shift stock. I have plenty of complaints about it.

 

Did it just get cold where you are? Could this just be normal warming the system stuff? Or does it matter how warm or cold the system is? Mine won't go into lock-up until it warms up, I slow down, and then speed up again. It is really trying to protect itself by warming the trans fluid up.

 

That's a good point. Does this condition go away once everything his heated up? What's your outside temperature been lately?

It doesn't get bitterly cold down here in South Florida, but every now and then in the morning before everything's at normal operating temp and a cold front's just passed (high 30's to low 50's F), it doesn't seem to shift all the way up as fast or lock-up as soon as during warmer times. This is right out of the service manual with regard to torque converter lock-up:


TORQUE CONVERTER CLUTCH (TCC)

The TCC was installed to improve the efficiency of the
torque converter that is lost to the slippage of the fluid
coupling. Although the fluid coupling provides smooth,
shock-free power transfer, it is natural for all fluid couplings
to slip. If the impeller (3) and turbine (5) were
mechanically locked together, a zero slippage condition
could be obtained. A hydraulic piston (6) with friction
material (7) was added to the turbine assembly
(5) to provide this mechanical lock-up.
In order to reduce heat build-up in the transmission
and buffer the powertrain against torsional vibrations,
the TCM can duty cycle the L/R-CC Solenoid to
achieve a smooth application of the torque converter
clutch. This function, referred to as Electronically Modulated
Converter Clutch (EMCC) can occur at various
times depending on the following variables:

-Shift lever position
-Current gear range
-Transmission fluid temperature
-Engine coolant temperature
-Input speed
-Throttle angle
-Engine speed


If you are in a cold climate, and the truck stops doing it altogether in the spring, you might just have nothing to worry about.

 

It's been doing it since Feb so I've already gone through cold, hot, and now back cold again. I just hooked up my sc tuner and I do have a line pressure sensor circuit p0932 dtc and a right rear turn lamp control circuit high B1648. I feel wicked dumb for assuming my buddy actually checked for codes at least to tell me. Looks like I got some research to do