Ok, did some googling and saw the tool I think you mean and yea you don’t need it. Get the offsets and press in new bushings ( or have the dealer do it, only about an hours work with a good hyd press) then follow what I copied below ( I wrote it out a while back on a 2388 shaker thread, I wasn’t retyping it....)
Take the drive belt off, mark the shaker drive pulley at 12 o'clock, then turn the pulley by hand and see where the mark is. If it isn't at approximately 6 o'clock, you haven't put the system back together correctly.
You need to loosen all the bolts on the bushings and centre the shaker on its stroke ( mark the extremes and find the centre) then you need 3 people, one to hold the pulley and the others to tighten the system. Throw the impact wrench in the tool box and leave it there it has no business being near a shaker😬 then Start with the bolts that go thru the header frame then the move on to the ones on the shaker fram and then the eccentric bolts and the two at the back on the upper lower transfer arms. Then check the 12-6 position again.
Also check the auger bed hasn't dropped on its bolts ( they do crack around the bolts on the sides we ( the dealer) had a local metal fab shop punch out 1/4 steel strips with double the holes and reinforced the sides if the auger bed ) and as was said in another post make sure it's not hitting the auger bed.
Another thing to check is that the main shaker hex shaft bearings are square to the frame of the machine. Find a point on the main frame ( there is a C channel there that works ) of the machine and measure to the bearings ( the eccentrics need to be off for this) it should obviously be the same.
Lastly ensure its shimmed central between the shaker arms, ask your dealer for the page out of the service manual that shows the amount of washers that goes between the arms and the frames, it gives you a start point but you may have to add or delete a washer somewhere to get it central.