On the King Tiger tracks, there are two sets of teeth on the inside of the treads. The most inboard teeth are supposed to fit in the slot between the two most inboard, paired idler wheels (like in the crude paint image shown)
The red line represents the inner track teeth and where they go when they are properly engaged. My problem, with both plastic tracks and now metal ones, is the inboard teeth want to jump out of that groove and move the track outwards. Then the tank will still run but will not run properly.
I did order the Henntec tensioner - for $73 -and it hasn't arrived yet. Perhaps this will solve the issue but perhaps it won't! In the meantime, here's something I came up with that does keep the teeth from jumping the idler wheel.
I took these two clear plastic spacers from a plastic parts storage box and glued them together. Of course, any piece of plastic about this length size and thickness will work. The idea is to prevent the tracks from jumping out of the idler groove.
I am holding them in my hand just for scale. You can see the plastic is not very thick and this is what I had around, so I glued the two of them together to make them thick enough to do the job. The length of the plastic piece as glued on (shown in the last photo of this post), is about right, but the width need only be as wide as the part of the hull it is glued to. So long as you can get the upper hull back on, it's probably not critical if they are a bit too wide and sticking out.
After gluing the two plastic pieces together (just to to make them thicker) i tack glued them under the part of the hull shown in the photo-just above the rear idler wheels. I made sure to leave about 2 or 3 mm clearance between the plastic shims, and the top of the tracks. Then I test drove the tank-they do keep the tracks from jumping out of place on the idler. The tracks stayed exactly where they were supposed to after doing every type of turn and spin the tank could do. When the tank is running normally the tracks don't touch the plastic. If you do some turn or some such and the tracks try to climb out of the idler slot, they hit the plastic, and due to the size of the track teeth and the plastic shim being there, the plastic prevents the tracks from jumping out of the idler groove. So instead of climbing out of place, the tracks just fall back down into the idler slot where they are supposed to be!
They are only plastic so they can't hurt the tracks, at all I think. And when the upper hull is in place the shim things are hidden.
