sorry, i meant shim the bevel gear out a bit from the inside, i read somewhere it helps the mesh by making att the tooth make contact with the other tooths or something. sometimes the crown gear does not reach all the way to the back of the bulkhead where the bevel is, but yes, the side shims go outside and do 1 ata time until the teeth bind a bit, then put that one on the opposite side. it should not be too tight as binding in the teeth wears out the two bearings on the bevel. also too tight a fit in the case wears out the 4 bearings on the side and allows play after some time, reducing the effectiveness of the shim. also too tight will mash up the plastic a bit and damage bulkhead. i've done all of these several times and have learned from my errors.