RM4665

Has anybody thought about putting it on a lift and running it up to the speed it shakes at and looking/feeling around the underside?

Sounds like another case of good tires fixing an issue.

I don't think TAC is a bullitin, I think it's when the dealer calls GM and opens a case and GM tech assistance tells them what to do. That's a reference number far as I know.

The acceleration vibration really is "normal" I think.

Anybody have the motor shimmed with success. I've seen a couple folks claim it solved their problems on other forums and it was mentioned once early on here, but that's it.

Mine was out of aliment when I got it, just slightly though. I got the 500 mile line as well. Something about suspension settling etc. It was fine by me since I knew I wanted to get the oil changed at 1000 and would probably have a punch list to go through at the same time.

Dealer couldn't remedy the rhythmic vibration in my truck. No other ideas. I threw in the towel and took it back. Left with another one, minus the shakes and added a 3.42 rear end. First 400 miles are going good so far.

Really, that's it. Acoustics? There is not a mechanical reason?

Did I miss it or what's the point of this flapper anyways?

It actually wasn't me, it was Brandon1282. I another post he said it fixed the proem he was having though. I quoted him.

I'm not so sure what you're talking about is not the below, to a lesser degree after looking around a little bit, but what do I know. If the Torque Converter was bad / getting bad signals, just not as bad as the next guy, maybe you'd just get a hum noise instead. brandon1282, on 14 Nov 2013 - 14:34, said: Just to update everyone on the rumble strip vibrations I was experiencing. I got the truck back 2 days ago and so far so good. Here is what the dealer reported: Road tested vehicle and found possible tire/wheel vibration. Removed all four wheels and road force balanced to find one tire out of range. This tire was replaced and then vehicle was road tested again. The vibration improved but was not eliminated. Checked for TSB's and none were found that directly addressed this concern. Contacted TAC and TAC suggested to utilize TBS PIP5149B. I followed all instructions of this TSB, checking for excessive spark retardation and connecting rod oil squitter condition. There were no conditions observed. TAC then directed me to utilize DOC ID#2102430 where I checked the operation of the control solenoid within the transmission. When commended to the on position, It registered full pressure and when commanded off it registered 0 pressure. After completing all tests found that TCM could not be 'pulse-width' tested, only command on or off. With these measurements we determined that the TCM was sending an erratic signal causing the torque converter to be commanded erratically. This caused potential damage to torque converter. Therefore, I replaced the TCM (Signal) and torque converter (damaged internally). Road tested vehicle; now operating to GM specifications with no vibration when tested under the original conditions. I have also noticed that the "floating Tac" condition I had earlier is no longer present.

After the last couple days I think I'll just ignore it. I forgot to pay attention to it on the way to work this morning and didn't notice it. I'll just make a punch list for the dealer of items when I go in for service next time, hopefully its a short list.

It is, but really negligible. If you weren't looking for it you you probably would not notice it. My guess is either this driveshaft is off a little as well or there is something else going on.

Probably. I'm debating having a local shop balance the drive shaft to get the last little bit out of it, they pulled another driveshaft off a truck they had in the lot. If I wasn't tuned into it, I probably would not notice what it does now. Ill either forget about it, or it'll bother me forever. It'll cost me $200 to have it taken out, balanced and put back in. Then again, what's left may not even be it. Vibrates about the same speed range.

Update. I had this issue and took it to the dealer. They isolated it to the driveshaft, replaced it and it's 98% better.

Not to rain on everybody's parade and I should just keep my mouth shut, but maybe it is the first time that guy has seen a vibration issue. Sure they sell a lot of trucks and I bet most of them don't come back for anything but oil changes until their free services run out, then they go someplace else cheaper. I know it's frustrating but they have to work through a process to fix things, just like any business. Short of replacing your truck right on the spot, it takes time to find out what's wrong and fix it. If they are that busy, they probably have lot of other customers to serve at the same time. I know it's frustrating, I don't doubt that at all. I also don't think GM would blow off the customer base of their best selling vehicle either. Go ahead, rip me a new one now for my post.

Got to thinking about this on the way home last night. If it were the case, I would think it'd go away if I put the truck in neutral while rolling down the highway. Gave it a shot and it still did it, about 67-75mph. Comes and goes in a consistent rhythm. In that scnerio the trucks not being pushed along anymore.... Am I right? Does that put the cause in something from the transmission back?

That makes sense and is a good analogy. Though I can feel it in my feet, Mostly the floor board. The balance did seem to lessen it, but it's nothing like the head shaker you describe

That's great, you gotta be happy to have that behind you. Let me ask you guys this...I've got about 6k miles on my truck, been great. I feel a small vibration in the floor, gas pedal starting about 67 up through maybe 75-80. Above that is seems to quit. I don't think it's anything like you all describe, or it just hasn't bothered me as much. I mentioned it to the dealer when I had it in for service and they road force balanced the tires. 11, 11, 15 and 9 lbs. added 1/2 oz to 2 of the tires. It's better than it was, but I still notice it. Probably just because I'm looking for it. Honestly, had I not read this forum I probably wouldn't notice. It's a very rhythmic vibration. I can feel it for a couple seconds, then quits for a couple seconds, then does it again. Over and over down the highway. Looks like there are a number of folks with different issues and probably not all the same thing. 18 inch Goodyear RS-A's. Same deal or no?

Of course, the truth is just that and lots of other owners can hopefully benifit from it too.