2010 Grinding when slipping in 4WD

Had new CVs installed and went from a 6" awful Rough Country lift from the previous owner down to just Bilstein 5100s all around.

I was driving up in the snow and when in 4wd every time the front wheels engage (Specifically the drivers front wheel I believe) I hear a horrible metal grinding sound. It doesn't appear to be speed related as it happens at 5 or 25mph, but only when extra traction is needed. It can roll in 4wd downhill or lightly accelerate without noise, but as soon as I need the extra traction it makes the grinding noise proportional to the speed.

I'm taking it back to the shop that did the work next week (soonest they could get me in) but I wanted to see if there were ideas here so I'm not going in blind.

 

The front diff mounts are the first thing to look at. The rear of the diff tips down under torque on the front drivetrain, then the driveshaft yokes rub on the crossmember, causing an awful grinding noise. Had it happen myself when a diff mount bolt broke.

 

Yup, my exact symptom. 4wd seemed fine until I put any real load on it.


I think there are some spacers and large washers that stack together for the diff mounts. Maybe they are missing some parts?

 

Damn. Well hopefully I didn't cause any damage driving like that. I avoided it mostly but I was in a blizzard in the mountains and needed 4wd. I doubt it made the noise for more than a quarter or half mile in total...

 

How did you get out of the 6" lifts? Did you find some welder to weld the 3rd cross members back?