Slight "thud" on moderate accel from standstill

[Bucky1]

I noticed today that it will not do it power braking. Only after it starts to move does it pop. Almost sounds like something in the front right shock. I believe that is an air ride control if I remember correctly.

 

[08grey]

Might be a ball joint.

Sent from my SM-G973U1 using Tapatalk

 

[wjburken]

I have had various causes for clunks when taking off from a stand still, most of which have been mentioned here.

With 130K, it could very well be a front shock. That’s close to when my front shocks have out on my ‘07 XL Denali. I would also inspect your drive axle as the boots like to split and let all the grease out.

 

[Bucky1]

OK. Great stuff. I checked the ball joints with my regular method and they appeared to be tight. But it is something I have missed.

 

[kbuskill]

There is no "air ride" up front, only on the rear if you have the "auto leveling" rear suspension RPO code Z69.

However all 4 shocks/struts are electronically dampened if you have the "autoride" suspension RPO code Z55.

There is also "Magnaride" suspension but the RPO code escapes my memory at the moment. But James @swathdiver knows.

If it sounds like it is coming from the front it could be a bad spring isolator allowing the spring to pop and make noise... a bad upper or lower control arm bushing... a bad sway bar end link or bushing.

 

[swathdiver]

There is also "Magnaride" suspension but the RPO code escapes my memory at the moment.

Z95 with G69

 

[avalonandl]

My AWD 2011 Denali (134k miles) does the exact same thing- not all the time.

Its not the motor mount because I did the throttle blip with hood up- ZERO movement.

 

[09_4WD_YUKON]

I think I have the same thing as you, but have not checked mine out. I also think someone on here mentioned checking the rear trailing arm bushings.

 

[CrashTestDummy]

At >100K miles, if you haven't replaced a motor mount, it is the motor mount. AND in the outside chance it is not, it soon will be, so replacing the driver's side motor mount with the Hummer mount will be money well spent.

 

[Rob Haag]

Mine turned out to be rear control arm bushings, I had a rattle with it too, over the slightest bumps, that drove me crazy. I had to move my axle just a bit when I installed the new trackbar, all the bushings back there were worn. Thux and rattle is gone now, I originally thought it was u-joints or transfer case