GMT900 high road noise in rear of crew cab?

[Stumpuller6.5]

Thats interesting, If its warm next weekend I may pull the back seat out and se what can be done. Id like to try completly plugging the vents and see if there is a difference then diagnose from there.

 

[sierra99]

Moved my bed to 1" space from bed to cab on both sides. Left side was 1" and passenger side was 1 and 1/4" . Move bed to 1". No change in noise.

Will put some dynamat over the passenger vent tomorrow. I'll post.


Hey Stumpuller 6.2, I have the same truck and color, but have a 5.3 and z71 4x4. I'm looking to swap out my door handles and mirrors from black to silver and change out the front grille to a Denali, and maybe look for some stock 20" rims. Could not get 20"s on a z71 from the factory.

 

[sierra99]

Fixed road noise

I removed the passenger seat today and placed some "ghetto dynamat" over the vent. I cut a 18" piece by 6" wide piece and started about 2 inches above the vent and went down to about 2 inches from the bottom of the rear of the cab. Make sure you leave about a golf ball size opening at the bottom for the truck to breathe. So my passenger vent will still work. I also dynamatted other opening including the passenger corner and also above and below the seat belt mechanism.

as for my "Ghetto dynamat" I used a product called "easy roof" from "home depot" $16.00 for a roll 6" by 25 feet. It is used instead of dynamat because it is cheaper and has one side with foil on it. Do not use the "peel and stick" from Lowes because it smells like asphalt too much.

Drove it all day and NOOOOOOOO noise.

Hope this helps.

 

[Stumpuller6.5]

Moved my bed to 1" space from bed to cab on both sides. Left side was 1" and passenger side was 1 and 1/4" . Move bed to 1". No change in noise.

Will put some dynamat over the passenger vent tomorrow. I'll post.


Hey Stumpuller 6.2, I have the same truck and color, but have a 5.3 and z71 4x4. I'm looking to swap out my door handles and mirrors from black to silver and change out the front grille to a Denali, and maybe look for some stock 20" rims. Could not get 20"s on a z71 from the factory.

Damn sounds like some good ideas, when you get that done post up some pics, might make me get some ideas too!

I removed the passenger seat today and placed some "ghetto dynamat" over the vent. I cut a 18" piece by 6" wide piece and started about 2 inches above the vent and went down to about 2 inches from the bottom of the rear of the cab. Make sure you leave about a golf ball size opening at the bottom for the truck to breathe. So my passenger vent will still work. I also dynamatted other opening including the passenger corner and also above and below the seat belt mechanism.

as for my "Ghetto dynamat" I used a product called "easy roof" from "home depot" $16.00 for a roll 6" by 25 feet. It is used instead of dynamat because it is cheaper and has one side with foil on it. Do not use the "peel and stick" from Lowes because it smells like asphalt too much.

Drove it all day and NOOOOOOOO noise.

Hope this helps.

That is awsome news, I knew it had to be the vents, so your fix does allow for some air movement? Do you possibly have pictures???

 

[sand man]

Moved my bed to 1" space from bed to cab on both sides. Left side was 1" and passenger side was 1 and 1/4" . Move bed to 1". No change in noise.

Will put some dynamat over the passenger vent tomorrow. I'll post.


Hey Stumpuller 6.2, I have the same truck and color, but have a 5.3 and z71 4x4. I'm looking to swap out my door handles and mirrors from black to silver and change out the front grille to a Denali, and maybe look for some stock 20" rims. Could not get 20"s on a z71 from the factory.

Damn sounds like some good ideas, when you get that done post up some pics, might make me get some ideas too!

I removed the passenger seat today and placed some "ghetto dynamat" over the vent. I cut a 18" piece by 6" wide piece and started about 2 inches above the vent and went down to about 2 inches from the bottom of the rear of the cab. Make sure you leave about a golf ball size opening at the bottom for the truck to breathe. So my passenger vent will still work. I also dynamatted other opening including the passenger corner and also above and below the seat belt mechanism.

as for my "Ghetto dynamat" I used a product called "easy roof" from "home depot" $16.00 for a roll 6" by 25 feet. It is used instead of dynamat because it is cheaper and has one side with foil on it. Do not use the "peel and stick" from Lowes because it smells like asphalt too much.

Drove it all day and NOOOOOOOO noise.

Hope this helps.

That is awsome news, I knew it had to be the vents, so your fix does allow for some air movement? Do you possibly have pictures???

i might try this fix

 

[Stumpuller6.5]

GM`s latest TSB. Supposed to be better then before.

10-08-58-001E as of march 8 2011.

 

[PenguinLTZ]

GM`s latest TSB. Supposed to be better then before.

10-08-58-001E as of march 8 2011.

What does it say?

 

[Stumpuller6.5]

They basically stuff more insulation into the vents themselves (by removing a panel to do so???). which everyone knows is the real issue, those damn vents.

I may give it a try one last time at the dealer here, but it won`t be till next week at the earliest..

 

[sierra99]

Just posted this on another site and want to spread some info and get GM to do something:

This is what I have done:
1. Placed dynamat on entire rear of cab behind insulator...................still have the noise
2. Placed Dynamat over vents.................................Don't do this......your ears will pop when you turn on the fan with the windows shut.
3. Had GM dealership do all service bulletins that pertain to this wind noise...................still have the noise....

Doing some more research with a friend who works at a dealership.

1. It seems that all trucks from 1999 to 2011 have the same vents. Part # 15927977. there are some other part numbers, but they just add a deflector to the rear of the vent for work body trucks and utility truck beds.

2. The Duct Vent Covers that are show in post 140 and 230 are vents covers that will work. it will deflect the noise and muffle out the noise on your dollar.

3. MAJOR>>>>>>> We have searched and found a part #20790482 $73.54. this is a rear insulator panel for a 2009 CrewCab, Extended Cab and regular cab pickup used in the year 2009. NO 2009's have a problem with wind noise from the rear. This insulator has the black rubber coating that does a better job of muffling the wind noise.

Part 3 20983473 - $50.24 is what has been used in all 2011's and some 2010's. This insulator has no black rubber coating ans lets our wind noise pass through into our ears.

Gm needs to use part #20790482 to fix this problem. This is the black rubber coated insulator.

 

[Zembonez]

I'm keeping an eye on this. Regular cabs get serious noise from the behind the seat area on the highway. Otherwise the cab is nice and quiet.