grinding noise

[yea thats my truck]

i have a 08 sierra 5.3 awhile back it started making a grinding noise when i first turn it on in the morning the noise increase when i accelerate and decreases when i decelerate once the trucks warm it doesnt do it any more hoping its not a transmission any ideas would be grately appreciated

 

[GMC Customer Service]

i have a 08 sierra 5.3 awhile back it started making a grinding noise when i first turn it on in the morning the noise increase when i accelerate and decreases when i decelerate once the trucks warm it doesnt do it any more hoping its not a transmission any ideas would be grately appreciated

yea thats my truck,
I would like to apologize for the issues that you are experiencing with your Sierra. I would recommend that you have your dealer look into this for you. They may be in the best position to assist you in diagnosing this issue. Please keep me posted and if you have any questions please feel free to contact me anytime.
Thank you,
Stacy GMC Customer Service