Ok well i have this geardrive set, and im missing the thrush washer on the back... now i tryed 1 today a .150 needle bearing thrush washer, and it seemed pretty big. So i assumed that it was not the right size... but the only other size i can get is .031 but thats 2 small cuz i measured the step on th back of the gear and it came out to .045 so its so small... is the .150 the correct size to use???????