tilt column help - shifting

[landarts]

So I have been working on my longtime project over the last seven years the "Fixrupr" build. When I tore the truck down to do paint and a few upgrades I had found a nice automatic van tilt at the local wrecking yard, so I pulled and paid the $20 gladly. Went home and listed the original automatic column for sale on Craigslist and sold it the same weekend.

Then I looked up the thread to convert the van tilt to my truck, cut in the new slot for the safety switch and cleaned it up and painted it. I finally got it installed and tried driving the truck after making a few adjustments to linkage that bolts to lower arm on column. When I put it in drive and start to drive it pops out and will not stay in that position. I did remove the linkage from the column to see how free it moved by hand to the transmission and it was very easy to shift the rod up and down. Put the column in park position and re-insert the linkage and tighten. Tried to drive and it would go a few seconds in drive as I went down the street, then pop out of drive. Any help or suggestions would be great!

1st picture is the old brown column and the van tilt in black.
2nd picture is the van tilt installed in truck.

[Andy4639]

I would think it's in the transmission if it's popping out of gear. The linkage wouldn't make it pop out unless it's binding up but you stated that it wasn't.
I would look at the transmission itself. It sounds like it's the problem.