Since I took delivery of my 07 LT3, I thought I had noticed this odd vibration on the truck when the RPMs were at about 1200 in any gear other than 1st.

Tonight I did some experiments and found that at around 1100-1300 (ish) RPMs there is a vibration that I think is coming from the transmission. You can feel it throughout the truck as well as in the steering wheel.

It only happens if you have your foot on the accellerator - not during a coast.

Anyone have a similar problem??

I tested this on several different roads and it happened at the same exact time, so it's not rough pavement. My wife already suggested that.

 

It may be that you are in 4 cyl mode. With such low rpms, are you giving it a good press on the accelerator or just barely tapping it? I have noticed the sound and feel of my hoe being in 4 cyl mode when I am on a flat or slightly inclined road. Change your display to the screen that tells you what mode you are in and test it. Hope this helps.

 

I get the minor vibration in 4cyl mode, too. It's more noticable when its raining for some reason... I also get the occasional shake at idle, like a skip or miss.

 

Maybe a faulty torque converter.
There have been some problems with a few TC's build prior to July 06 that have to do with the blades, where the vehicle will exhibit noise and/or a vibrations just prior to TCC lock-up.

 

As I have said in other posts today, I took my Tahoe to the dealer for some stuff to be taken care of.

This vibration thing is the dumbest one yet!!!

My complaint was duplicated on not only my Tahoe but on 3 others on the lot (so they say). I digress..... The documented response I got back from the dealer was "Roadtested vehicle for vibration at approx 1200 RPM's under accelleration. Verified concern. Checked for bulletins and PIs. None found. Called TAC (Case 9342616). Stated this is normal characteristic design."

How is a repeating vibration a normal characteristic design???? I have a problem with this.

Prior to the Tahoe, I had a 2004 Avalanche. For 2 years it leaked great amounts of water through the midgate. I finally got someone to look into the problem and was able to see exactly where the water was coming in from. Then a GM field engineer looked at it and made some major field modfications to the midgate's weatherstripping. It reduced the amount of water but didn't eliminate it. The tahoe came compliments of the GM Buyback Program.

If water entering the truck is 'normal' then why did GM buy the truck back??

How is a vibration at the same point every time normal??? There is obviously something that doesn't balance out well at 1200(ish) RPM.

Since they claim to have reproduced the problem on 3 other Tahoes, others in this forum must experience the same problem... I tend to think so at least.

I don't mean to sound crabby, but every time I bring a problem to GM, the generic response is "It's operating as designed". Was the Avalanche designed to leak?? It was like putting a screen door on a submarine. At least the AV was the right color - GRAY!!!

 

You really need to drive at least one other new Tahoe on the lot. This will give you the best feel of if it is operating as designed or not. Mine does not do it.

 

This response from your dealer sounds like the typical brush-off routine to me and sometimes that's all they can do for people that may be impossible to please.

Have you driven a Ford lately? Maybe it’s time.

 

ouch

 

I meant to put a smiley face on that post

 

Thanks for kissing the boo-boo. [:'(]