Is it possible to have an inner tie rod with source of knocking, but can't feel any movement on the upper end nor in the steering wheel. Steering feels tight. A shop checked all of suspension and said all are OK. That was month's ago and knocking appears to be slightly worse.

 

I had a knock that drove me crazy. I checked the ball joints and could not duplicate it, I had a shop check it and said everything is fine. So when I overhauled the front suspension, I replaced inner and outer tie rods, upper and lower ball joints and discovered that they were all worn and sloppy. None had grease leaking or anything like that just loose fitting. So yes they can be worn and they seem fine while everything is connected.

 

You can check inner tie rods by lifting the tire(s) off of the ground. Once lifted, you can move the wheel/tire left and right while looking at the shaft going into the inner tie rod. Any movement is an indication that is is worn.

A couple years ago, I was getting some knocking sometimes when off-road in 4WD but not on pavement. While I had it up on a lift at my brothers shop, my nephew was going around checking things, He told me my right inner tie rod was worn. He showed it to me and I thought it was not bad. However, a few months later I replace both inner tie rods and the knock off-road went away.

 

Not sure what driving scenario you are going through, but I daily a very twisty mountain road. One some of the tighter left/right/left/right areas, something binds up in my front end and pops as the weight of the truck shifts back and forth. I suspect its the upper ball joints, but just like you I can't recreate it during inspections so I haven't worried about it. Just a tip if you're doing the inspections yourself, jack it up by the lower control arm and not the frame. This will load the suspension the correct way and allow you to feel the play in ball joints if there is play. This is true for coil sprung or torsion bar front ends.

 

Just driving on flat roads. Any time I drive over bumps in the road, even small ones, there is a knock. It is a hard knock.

 

In most cases I would suggest this is a classic bad ball joint symptom. However the design of the sway bar links on some if not most of these trucks can create this situation as well. If you look up under the front my truck the link is essentially a long bolt attaching the sway bar to the lower control arm with a nut, a rather long hex shaped spacer, and rubber bushings on either side of the sway bar as well as the control arm. I had the spacer push through one of those rubber bushings once, causing the sway bar to slap the top of the spacer metal on metal as I hit bumps. It was quite a racket.

I also had a caliper bracket come loose once (shame on me for reusing the bolts instead of getting new ones that include new loctite patches). It also clunked when I hit bumps.

 

One more thing, it may help to list the year and configuration of your truck (4x4? Coil sprung or torsion bar if 98+ for example)