Intermittent grinding while driving

[snoop]

I am trying to diagnose this new grinding noise, kinda sounds like metal teeth grinding every once in a while. It just started when I took it off road for the first time, extremely mild sandy fire roads. Notable items are as follows:

• Sounds like metal teeth grinding
• Occurs for 1-3 seconds
• Intervals of 10 seconds to 10 minutes apart
• Happens while moving at any speed
• Happens under load and when just coasting
• Happens in any gear, low to neutral
• Happens in 4 high or low

Recent work

• Recently had front axle rebuilt by a reputable member on the forum, hes done a ton of em, 300 miles ago
• Removed VC 300 miles ago, flushed transfer case
• Recently flushed transmission 600 miles ago.
• Just noticed inspection cover on torque converter missing...

I will get video soon. I have read about bushings on the axle get dry but since it was a recent service I don't know if it was this is the culprit. Can sand and gravel get into the torque convertor area and cause a grinding noise?

 

[BILT4ME]

Check front drive flanges on front hubs.

 

[Ridonculous]

Did you get this resolved? I have the same thing going on and need to fix ASAP