Transmission Shifting Wierd

wzschirnt · January 28, 2011

Hi,

I have a 2007 1500 ext-cab with the VortecMax package. It has about 39,000 miles on it and the problem has existed since I bought it new.

The problem is with the trans shifting at low speeds (this is in 'normal' mode, not 'Tow mode'). When I go around a corner or slow to about 10mph and then accelerate, the transmission seems to have problems figuring what gear it wants to be in. Sometimes, it grabs 1st and then goes immediately to 2nd and sometimes it 'hangs' (acts like it is low on fluid) between 1st and 2nd for a second or 2 before going to either 1st or 2nd. Shifting into other gears is normal. Is the Torque Management program causing this? Or what?

It acts like no other Chevrolet I've driven in the past and I've driven other 2007 trucks (no V-Max however) and the problem was not present in them. Dealer says 'normal operation' (took it in 2 times). I have the ext warranty, so no skin off my nose, but I'd like it to act 'right'.

Am I wanting something unusual? Any ideas?

Thanks.

walt

Stevens03 · January 28, 2011

Doesn't sound right to me. My Vmax didn't do that

Dumb question, but is the fluid level right?

I'd keep pressing the dealership, but you've got to get them in the vehicle when its having the issue. When it acts up, call them and swing by and pick up the service manager for a quick ride. Express your concern that it's random but its definitely a problem. Keep on them.

Not sure if your truck applies, but there has been programming updates available for the transmission. Something to ask.

wzschirnt · January 28, 2011

Doesn't sound right to me. My Vmax didn't do that

Dumb question, but is the fluid level right?

I'd keep pressing the dealership, but you've got to get them in the vehicle when its having the issue. When it acts up, call them and swing by and pick up the service manager for a quick ride. Express your concern that it's random but its definitely a problem. Keep on them.

Not sure if your truck applies, but there has been programming updates available for the transmission. Something to ask.

Fluid is good. Even added about a pint to make sure. Will have to keep on the dealer about this and maybe ask about programming updates. I can make the trans do it 'on command'.

Thanks.

gmtech4 · January 29, 2011

Reprogram has a fix for the flare shift to 2nd

minibike132 · January 29, 2011

Reprogram has a fix for the flare shift to 2nd

+1 but there is other stuff too.

How much throttle input are you talking about when you are accelerating (use 0%-100% scale). And when you take it in be sure to not just say accelerating tell how much.

minibike132 · January 29, 2011

Reprogram has a fix for the flare shift to 2nd

If this were in my bay I think I'd throw a valve body and reprogram at it if I couldn't duplicate it. Write it up creatively and all the bases are covered on this one............ oh look at that the labor time is listed as ST on the valve body CHA CHING.

wzschirnt · January 30, 2011

Reprogram has a fix for the flare shift to 2nd

If this were in my bay I think I'd throw a valve body and reprogram at it if I couldn't duplicate it. Write it up creatively and all the bases are covered on this one............ oh look at that the labor time is listed as ST on the valve body CHA CHING.

Acceration is "easy" or "normal" - I'm just going around a corner or starting to go again after almost stopping. Harder throttle application, like when I'm towing, doesn't seem to do the same thing. I'll check with the dealer about any 're-program' fixes.

Thanks.

wzschirnt · January 30, 2011

Reprogram has a fix for the flare shift to 2nd

If this were in my bay I think I'd throw a valve body and reprogram at it if I couldn't duplicate it. Write it up creatively and all the bases are covered on this one............ oh look at that the labor time is listed as ST on the valve body CHA CHING.

Acceration is "easy" or "normal" - I'm just going around a corner or starting to go again after almost stopping. Harder throttle application, like when I'm towing, doesn't seem to do the same thing. I'll check with the dealer about any 're-program' fixes.

Thanks.

Oops, let's say 5-10% acceleration.

Hope this helps.

Thanks.

minibike132 · January 30, 2011

There is plenty of bullitens on the 1-2 shift. I don't post full bullitens but I'll post the numbers and the descriptions. The first one is the one I was thinking of that refers to the accumulator valve but there are other valves in the valve body that can cause the condition. Have fun looking for these, no matter what I would reflash the module and clear shift adapts and see if that does it.

#09-07-30-017A: Harsh 1-2 Shift at Light Throttle (Install New 1-2 Accumulator Valve Kit) - (May 20, 2010)

#10-07-30-003: Harsh 1-2 Shift at Light Throttle (Follow Bulletin Diagnostic Steps then Reprogram TCM, if Necessary) - (Jan 25, 2010)

#PIP3170G: Hard Or Harsh 1-2 Shift - keywords 4L60E 4L65E 4L70E automatic bump first noise PQC second shift slip transmission - (Mar 24, 2008)

#07-07-30-024: Information on 4L60-E M30 Rear Wheel Drive Automatic Transmission Valve Body Reconditioning, DTC P0741, P0756, P0894, Harsh 1-2 Shift - (Sep 27, 2007)