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Message: <blockquote data-quote="Canadian Steve" data-source="post: 1386116" data-attributes="member: 87538">Just to add my 2Cents .I have never opened up an FJR drive but have messed with Concours a little.However I did at one time build diffs and trannies for class 8 trucks, and did many Toyota diffs installing lower gears and lockers. The principles remain the same.....If a backlash setting was originally in spec and over miles has went out of spec (as mentioned above ,010 above max backlash), This is usually a sign that bearings need to be replaced. Tightening up specs by shimming alone on old bearings will in my experience lead to failure of that drive in a shorter time period than if it was just left alone. Most backlash increase comes from bearing wear, however a ring and pinion will develop wear, and getting a proper mating mark(most important for life of gear set) does not always mean the ideal paper spec. Looser is always better than tighter if going outside of spec.Often when just tightening up backlash with old bearings a gear whine will be the outcome. Tightening up pinion bearing spec with old bearings will result in bearing failure sooner than later.Also just recall that the dreaded BMW rear drive failure was imo mostly caused by to tight bearing preload setup from factory. (My old K1200LT did not suffer this issue (I checked) but many were wrong from the factory.Maybe..........some FJR drives were set up to loose from the get go. .010 is a big increase in such a small gear set.</blockquote>

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