2007 Sierra Slt With Hard Shift...

joe_black · October 31, 2009

I have a 07 Sierra SLT 2wd that has started to exhibit hard shifting from 1-2 and 2-3. It is enough to feel a a jerk and I thought it was weird. The fluid looks great and the truck has about 66k on it.. Yeah, 66k.. LOL... The 1-2 shift is more jerky than the 2-3rd shift and the rest of the gears are ok and it is ok while down shifting.

Let me know what you think..

Thanks

VMax2007 · October 31, 2009

Did you just buy it, or did you buy it new?

Nytemare · October 31, 2009

Did you just buy it, or did you buy it new?

Was thinking the same as you I'll bet....does it have a shift kit or vette servos

VMax2007 · October 31, 2009

Did you just buy it, or did you buy it new?

Was thinking the same as you I'll bet....does it have a shift kit or vette servos

Yep, or a tune?

joe_black · November 1, 2009

I bought it used... I got a great deal on it and I couldn't pass it up.

I really don't know how to tell, I went to the dash and reset all the factory settings and i hooked my scanner up and reset the ecu. I honestly have no idea how to check the program on the ecm or tcm....

Do people usually install shift kits and fool with the 5.3 2wd Sierra???

VMax2007 · November 1, 2009

I bought it used... I got a great deal on it and I couldn't pass it up.

I really don't know how to tell, I went to the dash and reset all the factory settings and i hooked my scanner up and reset the ecu. I honestly have no idea how to check the program on the ecm or tcm....

Do people usually install shift kits and fool with the 5.3 2wd Sierra???

Custom tuning and Vette Servos are very popular mods.

joe_black · November 1, 2009

Really? The truck was stock or appeared to be stock when I bought it...

One thing in know is that it will move out of 1st and 2nd when I give it a little gas, I mean little gas. Also if i baby it in ist and second it is jerky but if i give it a little more gas it will be a lot smoother.... I just don’t always need to accelerate that hard, and try to cruise at times to save gas.... It usually shifts around 2k in those gears also, is that normal?

Is there any way to tell???

Stevens03 · November 1, 2009

If you just got it, then have the dealership look it over.

Nytemare · November 1, 2009

There is really no way to tell if it has a shift kit or corvette servos without opening up the trans or servo housing. But from the sound of things it has one or the other.

As for a tune you can get the ECM re-flashed to a stock tune.

VMax2007 · November 1, 2009

There is really no way to tell if it has a shift kit or corvette servos without opening up the trans or servo housing. But from the sound of things it has one or the other.

As for a tune you can get the ECM re-flashed to a stock tune.

Not if it's locked.

joe_black · November 1, 2009

There is really no way to tell if it has a shift kit or corvette servos without opening up the trans or servo housing. But from the sound of things it has one or the other.

As for a tune you can get the ECM re-flashed to a stock tune.

Not if it's locked.

To answer everyone’s questions and comments....

I bought it from a Nissan Dealership.

I just had the axle lubed at a GMC store and they said nothing.. I asked if its normal and they said it was for some models. I am out of warranty so I, assume they would have said there is a problem since they can cash in.

I was just wondering if there was an easy way to detect without tearing things apart, or a simple way to check thru the cluster, or to look at the ecm for a chip or sticker.

Or flat out my tranny is fu#%ed up.

Thanks for everyone’s help, and if you all have any more ideas lmk...

Nytemare · November 1, 2009

There are no more chips.

There may be a sticker on the ECM, but probably not.

There is nothing on the cluster to look at your ECM tune....just operating parameters, like fuel economy trans temp...etc.

joe_black · November 2, 2009

There are no more chips.
There may be a sticker on the ECM, but probably not.

There is nothing on the cluster to look at your ECM tune....just operating parameters, like fuel economy trans temp...etc.

Gotcha,

I asked because on my super duty I could look at my mpg and is was high like 26 mpg and I knew it was lying and my tune was active. Also, i would dump tons of smoke.

I was hoping there are some tell tell signs... I'll have it scoped and the tcm and ecu checked.

Z45 · November 2, 2009

Take it to a independent trans shop professional (not a chain store shop) and see if he will drive it for an evaluation. A trans pro will know more than a dealer about common trans problems etc.

That's what I would do.

empirezclub · November 5, 2009

You can see if the vehicle exceeds 100mph since the first thing most people change when they tune. If you don't feel safe doing it on a public road you can put it on a dyno and you will now how much power you have too. Of course if they just did a vette servo the top speed limiter should still be in place.