Setting up vehicle (forklift) physical asset with lifting function problems

[Perplexitar]

Hello people,
I hope i post it into the right category.

Ive set up a vehicle ( reach truck / 3 wheeled forklift) and it basically functions well as i had only the rolling chassis and the wheels. A bit of fine tuning some settings and I had the desired drive characteristics.
I decided to add additional function to make the forklift lift stuff - and here the problems began.

It was either no collision, or no physics. somehow I cant get it right, probably due a bad way of implementing the lifting function, as it seems only to work when i set some physical bodies to kinematic, but then “drive” behaviour is goin wild.
Mostly I can not get it to drive with proper set up characteristics (like truck cant start drive, i believe happens due to unlocking Z movement and the physical body drops and creates huge friction?)
I had probably all forms of how a forklift / vehicle should not behave. From space ship hyperdrive behaviour from lifting the mast / forks to being a spin out ride at a fair.

This is my physical asset:

This is my bone hierarchy i deem relevant to show:

I have a few versions where i switch the parent of the shaft, as this should actually be the driving force that the inner mast is attached to.

This is the lifting function:

This is how it looks:

This is my Animation blueprint:

Those are the ideas I have left:

Now I assume I am doing something completly wrong here and it nearly working was just a bad starting point with lots of work arounds, or the problem lies just in setting up properly the physic bodies and constraints. Another point may be the wrong set up of parents in the bones.

My Idea of the ideal behaviour is as follows:
Forklift behaves as one would expect, maybe a bit sporty. The mast should influence the drive characteristic, but not a lot. When the mast is extended, it should response to collision (e.g.: crash). The forks should also respond to collision so i can actually lift stuff.
The lifting function is controlled by the mousewheel - i could figure out how to interpolate it so it is smoother.
After trying for a week, I am at the end of my very very limited knowledge, as i am very new to this.

Thank you for your time reading and support!

Best regards

[Perplexitar]

Update:
my collision box does this:

I have set it up as the example vehicle, but it still seems to jujsut stick in place and extend.

[MonkiDG (Monky)]

Everything you did is incredible, I’m trying to get the thing up front but I can’t.

[Perplexitar]

Solution to update:
i had a collision box, which was falling down on spawn.

Solution problem:

The concept was totally wrong.
To achieve having a forklift with physical collision to set up, and drive properly, ive changed the following things:

switching all the bodies to default, except for the wheels.
implement a linear drive motor for the masts and fork carriage.
Constraining was quite tricky, needs alot of fiddling. Important here was the position of child and parent, which ive set to 0, otherwise the forks always kept lifting.

The blueprint had to change accordingly.

also, the mousewheel values had to be clamped / reset while transiting from free lift to full lift to ensure good mouse wheel control

the ABP code is not needed anymore.