Originally Posted by
bertrandsv87
Anything that rotates around an axis needs to have the same amount of centrifugal force pulling on each side of the axis, in order for the system not to destroy itself. When you shim the web gears, you are actually moving the weight of the gear around to get a tighter fit, but might be causing the gear diff to become internally unbalanced. In addition, the gear having moved causes a change in oil flow around the gear, which worsens the imbalance . It's very hard to get it right, specially when some parts come with small defects, and even if you do, it won't last long because the web gear center holes will naturally enlarge due to friction, and consequently pulling the teeths apart, before the diff blows...
WOW! Thats a great theory! I have not had any issues with the composite gears and improper shimmimg will shorten the life of any diff. Compsite diffs are not made to have long life but more performance in the race. If you dont properly shim the diff in an effort to make the diff smoother with lighter action; the life of the diff will be reduced and fail under load. Im not sure where your experience is based from but in my experience with gear diffs and gas cars; there is no vibration in the diffs. The diffs do not spin free and are placed under load by a rubber belts while in the car. You might be correct if the diffs were to free spin at 50-60 thousand RPM..