I have a 2001 F350 with a7.3 power stroke, 6 speed manual with manual t case and hubs. I have a bad grinding noise when in 2 wheel drive. Similar sound as if you are trying to shift t case into 4 wheel drive too slowly. The grinding is constant in 2 wheel drive, but if I shift it into 4 wheel drive, the noise completely goes away. I have been driving around in 4 wheel drive (T case only, manual hubs not locked) for the past 2 days. If I shift back into 2 wheel drive, a constant terrible grinding noise returns. Any thoughts on what could be wrong, and why it goes away in 4 wheel drive?????

 

Post your issue in the Super Duty & Heavv Duty forum.
This in light duty gas.
Good luck.

 

sounds like the transfer case "arm" does not fully move into the 2 wheel position ?

 

Either one or both of the IWEs are not completely disengaging when in 2WD - prolly a vacuum issue.
Whooops! Cancel that - prolly have manual locking hubs

 

does your 4 x 4 floor shift level feel like it strokes full to both ends ? THh F150 floor shift has shown to have "sticking" or "tight" bushings and pins after 10-15 years and will eventually lockup and not move at all.

 

I don't know if your truck looks like this system, but its good info.

https://www.ford-trucks.com/forums/1...-write-up.html