A+ idler gear shim for all A+ engines. It is very critical that the idler gear have the proper clearance between the gearbox and transfer housing. Too much and gear damage and excessive noise can occur, too little and bearing failure and surface galling is sure to happen.
 
Correct specification is .003-.006".
 
Available thicknesses as follows: 
.132-.133" - Bare
.134-.135" - Yellow
.136-.137 - Red
.138-.139" - Blue
 
Not returnable.