Wish i had the time to experiment with it, I rode in an 09` 3/4 loaded exactly like mine, night and day difference.
GMT900 high road noise in rear of crew cab?
- Thread starter Stumpuller6.5
- Start date
Wish i had the time to experiment with it, I rode in an 09` 3/4 loaded exactly like mine, night and day difference.
The best way to solve that rear bow-tie issue is to just take it off! 
Crew Cab noise
Hey guys, found this forum after doing a search for "noise from rear crew cab" and I have it also on my 2011 crew cab 4x4 slt sierra. Brought it into the dealer and showed them the TSB. The did the repair , just as stated in the TSB and replace the rear right vent. Guess what..........still does it.
But I did notice (while pumping gas today) that the right rear flaps were open with the heat running inside the truck. Flaps on passenger side only were wide open. especially the top flap (there are a total of 4, I believe) I turned the heater off and the flaps closed up. I sat in the bed with a buddy driving and the flaps do open up while driving down the road (with the heater in the off position) It seems like the air is coming up from between the bed and lifting the flaps. But why not the driver's side?? Could be that the fuel tank is dispersing the air differently on the driver's side?? But why do some other crew cabs not have this problem???
The padding seems like it is so thick that it would deaden the sound of a freight train. There must be a way that the noise it getting through. I will check it out this weekend.
I wight try to get a 12" by 12" piece of DYNAMAT and try to put it over the vent from the inside , bit leave the bottom open. Kind of form it around the top and sides, but have it go 12" down and leave the bottom open.
I will tell you what happens??
Just a question?? Is there any more sound deadening material in the doors or cab area anywhere in a SLT or Denali pick up that a SLE does not have????
If so what is it???
I know that the cheaper home dishwashers have no sound insulation and the more expensive ones do have a fiberglass wrap around the outside in order for it to seem better, well it is, it's quieter.
Hey guys, found this forum after doing a search for "noise from rear crew cab" and I have it also on my 2011 crew cab 4x4 slt sierra. Brought it into the dealer and showed them the TSB. The did the repair , just as stated in the TSB and replace the rear right vent. Guess what..........still does it.
But I did notice (while pumping gas today) that the right rear flaps were open with the heat running inside the truck. Flaps on passenger side only were wide open. especially the top flap (there are a total of 4, I believe) I turned the heater off and the flaps closed up. I sat in the bed with a buddy driving and the flaps do open up while driving down the road (with the heater in the off position) It seems like the air is coming up from between the bed and lifting the flaps. But why not the driver's side?? Could be that the fuel tank is dispersing the air differently on the driver's side?? But why do some other crew cabs not have this problem???
The padding seems like it is so thick that it would deaden the sound of a freight train. There must be a way that the noise it getting through. I will check it out this weekend.
I wight try to get a 12" by 12" piece of DYNAMAT and try to put it over the vent from the inside , bit leave the bottom open. Kind of form it around the top and sides, but have it go 12" down and leave the bottom open.
I will tell you what happens??
Just a question?? Is there any more sound deadening material in the doors or cab area anywhere in a SLT or Denali pick up that a SLE does not have????
If so what is it???
I know that the cheaper home dishwashers have no sound insulation and the more expensive ones do have a fiberglass wrap around the outside in order for it to seem better, well it is, it's quieter.
Welcome to the site sierra99 
Interesting info you have there.
Interesting info you have there.
nubuilder
Why buy new when you can restore?
Welcome sierra99!
Interesting info indeed.
Question though:
Are the vents on the rear of the cab any different on a CC versus a Reg. or Ext.?
The cab itself shouldn't have anything to do with it since the bed is the same distance away from the cab, but maybe you are right in that something under the truck is that different that it causes different pressures.
Interesting info indeed.
Question though:
Are the vents on the rear of the cab any different on a CC versus a Reg. or Ext.?
The cab itself shouldn't have anything to do with it since the bed is the same distance away from the cab, but maybe you are right in that something under the truck is that different that it causes different pressures.
Welcome sierra99. As for the door insulation, it is the same among the models.
I have actually heard that the 2011`s may be worse than the 2010`s. I plan on dynamatting the whole truck, windows and all. 
I will like to know how your experimenting goes, I will certainly be experimenting when the temps get warmer here.
I will like to know how your experimenting goes, I will certainly be experimenting when the temps get warmer here.
I have realized that the drivers side gap between the bed and cab is 1", but the passenger side has 1 and 1/4" gap.
My friends 09 Crew cab has 1" gap on both sides. And his rear pad is different. His rear pad has a hard rubber side that faces the interior (seat area) and the side facing the metal exterior is the fabric matting. I looked into getting an 09 mat and they are now all the same as the new ones (all fabric, no rubber side)
I had him run his heat all the way up with the windows closed and both of his rear vents remained closed.
BUT, he does have a complaint of wind noise at his drivers top windshield, that was no there when he bought it.
I have read some other posts on this being a common problem in the 07-09 years and maybe GM has decided in order to fix that problem, they will let more air come out the vents when closing the doors and thus went to the newer rear pad.
Just drove around the block with my buddy driving and me in the bed. My vents do remain closed, but he can hear the noise clearly.
Could the hard rubber piece that is on the 09 be missing from mine (Ours)??
My friends 09 Crew cab has 1" gap on both sides. And his rear pad is different. His rear pad has a hard rubber side that faces the interior (seat area) and the side facing the metal exterior is the fabric matting. I looked into getting an 09 mat and they are now all the same as the new ones (all fabric, no rubber side)
I had him run his heat all the way up with the windows closed and both of his rear vents remained closed.
BUT, he does have a complaint of wind noise at his drivers top windshield, that was no there when he bought it.
I have read some other posts on this being a common problem in the 07-09 years and maybe GM has decided in order to fix that problem, they will let more air come out the vents when closing the doors and thus went to the newer rear pad.
Just drove around the block with my buddy driving and me in the bed. My vents do remain closed, but he can hear the noise clearly.
Could the hard rubber piece that is on the 09 be missing from mine (Ours)??
