Each saw is different, but look at the gears and try to figure what needs to be done to get them to mesh right. Some of the AM large gears would not fit in the case, and I filed some of them down (insert in cordless drill and hold against a file).
Often the axel on the small gear needs to be shimmed, cut a small piece of flashing to do this. Make sure everything is greased so it does not wear and operates smoothly. Some of the threads on the bar adjusters are not lined up with the axle and need to be bent to operate smoothly, and a couple of times I had to put a flat washer under the large gear to get it to line up properly with the small gear.
Lube everything and work it back + forth a few times, then put the pieces in place and see if it works smoothly, and if not try to figure what does not look right. Always make sure that rubber washer is inside the large gear.
Often it is trial + error. Best of Luck with it. I was very pleased my most recent kit (w/blue covers) worked just fine, so perhaps they have finally addressed the problem (or I got lucky).
Also, if your AM and OEM gears are different sizes, try mixing and matching. Sometimes that also works. HL Supply sells some decent low cost gear sets.
