Does anybody know why my truck does not stay in 4hi? Sometimes after I shift into 4hi, the gear shifter slides back into 2 wheel drive. Any thoughts?

 

Never heard of that one before.............

 

This happened to a Chevy I had. The shift linkage needed some lubrication and would jam up just as you were putting it into 4hi. This would cause it to not fully engage the gear and as you started moving the force from the gears would pop it out of 4hi. I got under there and gave the linkage a cleaning and lubricated the pivots. When I got under there the linkage looked good but a little dirty.

It might be worth a try to just crawl under and take a look.

 

Thanks I will check it out

 

I had this happen a few times at the proving grounds when the 3rd gen was in development. Usually its just becuase the gears are not lined up enough when shifted into 4hi. It should feel solid when you shift into 4hi. Make sure the shifter pulls all the way back when you shift.