In OD under power, the Ex hesitates sometimes.

[Byrd91]

Now that I have 4.56s I'm using OD a lot more. I've noticed sometimes on uphill pulls or when under power in OD the engine/tranny will hesitate. Its like it goes to downshift but just stays in overdrive. Actually thats just what it feels like. I have done the throttle cable mod, but that was a long time ago, and this is a recent thing. I'm not sure if it could be the kickdown because when I really step on it it kicks down, this usually happens when I'm being conservative to try to keep in in OD, you know what I mean? Anyway, any ideas would be great. Also, any way to check or lube the kickdown cable. I have a bunch of relays and crap from the remote starter so I thought I'd check before I pulled all that out.

 

[Alec]

If it's trying to kickdown out of OD, just let it instead of modulating the throttle to keep it in OD. This can actually put more stress on the torque converter and tranny than just letting it downshift.

Just my 2 cents.

 

[Byrd91]

Thats the thing, it doesn't kick down. Seems like it will but then goes into OD again. Its really weird. With the 4.56s I usually have plenty of power so it doesn't need to kickdown much. I'm really wondering if thats actually what it is. Thanks for the input. I'm going to keep an eye on it to try to nail down the circumstances that it happens.

 

[MrShorty]

The 3-4 shift is electronically controlled by the PCM. There's also the torque converter lockup clutch that can feel like a shift when it disengages. Next time you feel it shift, see what happens if you put the selector from OD to D. If you feel it shift to 3, then it's possible what you're feeling is the TCC disengaging. Beyond that, I would recommend backprobing (use a breakout box instead, if you have access to one) the TCC and OD control circuits and see what the computer is telling the transmission to do.

 

[Byrd91]

Its definitely not the TC disengaging. Its still engaged after it does it. Its like it shifts from OD (TC locked) to OD (TC locked). I'm not sure how to go about checking the computer, any simple way of doing it?

 

[MrShorty]

Start with a wiring diagram (The ones at autozone.com are adequate for this circuit) to identify the wires and get a feel for the circuit. Use a DVOM to backprobe the circuit between the transmission connector and the PCM. I usually measure the voltage drop across the computer (positive lead is on the ground side of the solenoid, negative lead is to ground). In this configuration, the voltmeter will read ~12 volts with the OD disengaged and ~0 volts with the OD engaged. Just be careful that you don't accidently short something out or cross wires. Also, if you backprobe at the PCM connector, be careful not to damage the contacts or short any of the other wires out (This is where a breakout box would be real nice if they weren't so expensive).