Bucking/Clunking at takeoff?

[chip]

Hello all,

On my 2010 6.2 AWD, I have a bucking/clunking coming from what feels like the driver's side front when I takeoff from a stop. The harder I takeoff, the more noticeable it is. When I say "takeoff", I mean regular driving (not WOT). It feels like the front/left axle is bucking, but there isn't any obvious noise. I originally suspected motor mounts, but those have been replaced. Is there a suspension and/or drivetrain component that I should be looking at? Has anyone had this issue and resolved it?

Thanks in advance.

 

[Joseph Garcia]

Check you front drive shafts and CV joints for any noticeable play. If you can't identify and visible issues, then do the following.

I recommend that you take the truck to a trusted local repair shop, and get the truck on a lift with the wheels off the ground and with someone inside the truck. Put the truck in gear and press the gas pedal a bit, and see if the noise also occurs in the unloaded situation (wheels off the ground). If the noise still occurs, then the Mechanic underneath the truck can go around, with a stethoscope if necessary, and locate the source of the noise.

 

[09_4WD_YUKON]

Check the motor mount?

 

[mikez71]

He said he replaced motor mounts...

Maybe the front diff bracket? Especially being AWD..

 

[Fless]

Crossmember bolts have been known to get loose. Check and torque to specs.

 

[rdezs]

Front differential mounts...

 

[chip]

Front diff mount is sounding very likely. Thanks for the input! I appreciate you all.

 

[Joseph Garcia]

I had clunking, but no bucking. I replaced my front differential mounts, and the clunk disappeared.

 

[rdezs]

That front differential rocking on the mounts makes a hell of a clunk...