2008 Yukon Denali AWD Clunking/jerking

[KimCan]

I have a 2008 Yukon Denali AWD. It was making a HARD clunking noise/jerk when shifting into each gear at a low RPM. We found out that the Front differential mount was broke. We went ahead and replaced both of them just to be on the safe side. Now the issue is only when it shifts from 4th into 5th gear. If you get on it from the get go though, it shifts perfectly NORMAL with no issues.

Any ideas what this could be?

 

[kbuskill]

I have a 2008 Yukon Denali AWD. It was making a HARD clunking noise/jerk when shifting into each gear at a low RPM. We found out that the Front differential mount was broke. We went ahead and replaced both of them just to be on the safe side. Now the issue is only when it shifts from 4th into 5th gear. If you get on it from the get go though, it shifts perfectly NORMAL with no issues.

Any ideas what this could be?

Are your engine mounts good???

 

[KimCan]

Are your engine mounts good???

yes both were replaced as well because one was cracked.

 

[thompsoj22]

Just an opinion as i also have the xl1500 denali 08 and knotice that trans is easily "confused" under light/no load conditions. if i am only cruising around town and am lightly accelerating the trans on occasion will "jerk" between shifts or get confused in a "lead/lag" configueration. if the vehicle is accelerated in a determined manner it shifts flawlessly. I drive this vehicle gently but at times maybe to much so, it is a 6k lb heavyweight and dosent really like slow cruising around town?