TXSierra07
New member
- Joined
- Aug 20, 2015
- Messages
- 1
- Reaction score
- 0
- Points
- 0
Good morning everyone, simply put I'm pretty well at a loss on this one. I have a 2007 GMC Sierra Classic SL Work Truck package with a 4.8L V8, automatic 2WD at roughly 116.5k miles.
Here's my issue: From a cold stop, as accelerating, there's a higher pitched whining (more like a winding up noise) that directly correlates to the RPMs. As it shifts out, it will still do it from the cold start, up until 3rd where it either stops or becomes too quiet for me to hear. However, if I drive in Reverse it doesn't make the noise, or if I perform a rolling stop and accelerate it doesn't do it unless I accelerate hard. It also seems to stop momentarily if I hit a hard bump while the noise is taking place.
Note: There has been no changes in the way it shifts, no hard shifting or slipping whatsoever, just seems to be a noise now that doesn't sound good.
Honestly, I'm pretty well stumped on it. I've tried changing out the transmission fluid/filter and it is still persisting, but it definitely sounds like it is coming from right under the cab in the transmission area. The u-joints on the drive shaft seem sound, rear end oil is good, oil was just changed in the motor and all fluids are in good order.
Was hoping to see if anyone else had some ideas as to what it might be.
Here's my issue: From a cold stop, as accelerating, there's a higher pitched whining (more like a winding up noise) that directly correlates to the RPMs. As it shifts out, it will still do it from the cold start, up until 3rd where it either stops or becomes too quiet for me to hear. However, if I drive in Reverse it doesn't make the noise, or if I perform a rolling stop and accelerate it doesn't do it unless I accelerate hard. It also seems to stop momentarily if I hit a hard bump while the noise is taking place.
Note: There has been no changes in the way it shifts, no hard shifting or slipping whatsoever, just seems to be a noise now that doesn't sound good.
Honestly, I'm pretty well stumped on it. I've tried changing out the transmission fluid/filter and it is still persisting, but it definitely sounds like it is coming from right under the cab in the transmission area. The u-joints on the drive shaft seem sound, rear end oil is good, oil was just changed in the motor and all fluids are in good order.
Was hoping to see if anyone else had some ideas as to what it might be.
