I'm writing this thread primarily to help me try keep my sanity for the next week while I wait. I have an appointment in a week at a transmission shop to have a rack inspection performed. I have already had the car to a general auto shop that does NOT perform transmission work; they have ruled out the tires, wheel bearings, and drive axles. I have a 2008 Cobalt, 2.2L, A/T, 78,000 miles. I drive 100 miles per day on the interstate, 6 days a week.

There is a bearing noise in the RF and a slight vibration in the steering. The noise begins around 45 MPH and continues to get louder as the wheel speed increases. Over the last 4 days, the noise has gone from being very faint to being heard over the radio. There is also considerably more play where the RF drive axel goes into the transmission than the LF drive axel. The general auto shop thinks that it may be the RF output shaft bearing.

Does anyone have any thoughts on what it may be and how the problem may be repaired?

Thanks!

 

Right front hub bearing.

Usually can get it as a hub/bearing assembly. Makes it much easier to replace then replacing just the bearing.

 

If the noise changes when u turn side to side then it's the hub bearing, if it doesn't then it's more then likely the carrier bearing on the right axel. It's the center bearing that bolts to the motor where the the axel splits

 

Thanks. Any other thoughts?

 

Keep thread posted having similar issue, after hitting a coyote at 3am, sound doesn't change left or right like a wheel bearing would.

 

there is not passanger side axle bearing evil ss he said its an automatic i am a gm transmission tech at the dealer that trasnmission has low faliure rates i highly doubt u have a transmission issue
mostly all passanger side axles going into the transmission are loose, sloppy. if this was an issue or to much play you should see transmission fluid leaking from this axle seal. most likely you have a right front hub bearing making noise. put car on hoist turn off trac control, lift up ebrak 1 click have some one get in the vehicle and put it in drive and spin the wheels to 45-and up where ever noise is most pronounced and listen to each hub bearing with a mechanic stethescope or long handle screwdrive to the hub and other end to ur ear make sure it long enough and u dont put ur hands or head by any spinning parts. isolate which hub bearing is most noisy they may echo threw each other side to side or both be noisy start by replacing the loudest 1st.

 

This sounds like my issue

When taking a left turn i get a grinding noise from the transmission and I can feel it in the shifter. I have taken it to multiple shops including GM and they said the hubs are fine, I tried replacing my passenger axel and it still grinds.

 

Thanks for all the information. It sounds like I need to get a second opinion. I'll post an update later in the week.

 

***UPDATE***

Today the LF wheel sounded like it was full of rocks. I took it in and they replaced both front hub bearing assemblies. No more noise or vibration!