transmission noise

[ws6guy]

I'm having a noise when the trans shifts from 2nd to 3rd at low RPMs (around 1500). It only does it while putting through a neighborhood or in slow traffic. It's hard to describe the sound but it's like "VRRRUM". I'd say it does about 75% of the time but at times it is barely noticeable and other times it is clearly heard. The truck is a 2013 with the 4.8L with the 4sp transmission. I purchased the truck used with 20,000 miles and I noticed the noise shortly after buying. I'm still under bumper warranty but the dealer couldn't locate the problem. Any idea what this is or if it's something I should worry about?

 

Thanks!

 

[GMCustomerService]

Hi ws6guy,

 

I can understand how frustrating it can be to diagnose an intermittent concerns. I see that you are reaching out to the forum for additional insight, however, if you would like to continue working with your dealership, we'd be happy to look into this further.

 

Have a great day,

 

Anthony Z.

GM Customer Care