islandboy

I know there is probably a million posts for this but im new to this site and i scanned around but no luck to finding my answers. When i put it in 4 lo it will stay in for a couple seconds until i try to start moving forward than it slips out and makes a grinding noise. so I had my friend sit in the car and move it into 4lo, while i gently tapped the linkage underneath and it would slip out all to easy. curious if there is any way to adjust my linkage or tighten it up or anything? ( it is lifted 4.5" )