No the big ypullies are in the corners of a square and the two idlers and small toothed gear are in the center with the small toothed gear on the right.thanks..

if it is knocking in reverse gear , that is an indication that a tooth of the reverse gear or reverse gear idler is badly chipped or broken
it will require a box strip down and gear and bearing replacement
best stick with the same gear box as there may be too many difficulties to fit a different box

Dana
idler gears are used between to shafts to change direction of shafts or positions shafts for better alignment for transferring motion
to that end they are used in engines , gearboxes, sewing machines, lawnmowers and just about anything mechanical
So post a new question and this time remember that small details like make , model, year, equipment type, gear , sprocket , position and use will probably get a more definitive answer

There should be an idler pulley in the system. Loosen off the big nut in front of the pulley and there should be a smaller nut or flats on the shaft. Turn this and the pulley will travel up or down a toothed section behind the pulley. When adjusted tighten the big nut.

it the motor instead of the chain?.... line up the dots TDC the idlers in the middle. thats SBC or BBC small block & big block

The idler tensioner might be bad. Can you get to move counter-clockwise at all either? The tensioner has a large heavy spring mounted in a pot-metal housing, so tensioners often go bad. Might be an idea to remove the tensioner and take a look at it.

Good day this motor / on the crank pulley is it gear with teeth or plat with hole

The noise is the tooth engaging your parking dog in the trans. think of a big gear with square teeth and a plunger that fits into the valley of the gear. not always does the plunger hit the valley so when you roll a little it comes off the high point and settles where it belongs

there is a hole in the cam gear that if you look through it with a mirror and light you should see a small notch in the cam cap. on the crank gear there is a small divot between the teeth just to the left of the keyway notch that should align with a small dimple on the oil pump cover

Look at the back side of the headlamp assembly. There are a couple of ears that stick out, right above a small silver toothed wheel. Using a suitably long phillips screwdriver, insert the driver down into the 2 small ears, and then the screwdriver should contact the small toothed wheel. The ears provide the proper support for the screwdriver to mesh with the toothed gear. Spin the screwdriver, and the toothed gear should spin, also. Rotate the driver in whatever direction to adjust the lamp beam. This will gibe you what you need. Hope this helps; any questions; please repost.

i'm assuming you mean gear box? are you sure it is square? many of those are 10mm hex key

good luck