Are these gears ruined ? In hindsight it looks too deep, would this cause a whine and scarring in less than 100 miles or is that from break in procedure or too much bearing preload ? No scratches to the feel but definite scarring. In your experience once these develop a bad whine, are bearings or gears shot & need replaced or is it a matter of adjustments and parts are ok ?
1st thing I found is backlash is tight, .006. I swear I set that at .010. I also have more bearing preload than I normally put in, that's from watching youtube videos for improvement
. I've never had a problem with my installs of used sets. Could be I've just been lucky till now.Fresh motor and new rear gears hit the street 3 days ago for test and tune. 71 F100, 31 spline 9" with new 3.5 gears installed by me. This is the 1st new gear set I've installed, all others being used sets. Noticed a whine starting 2nd drive out, 3rd drive it's worse. I probably set it up wrong.
I found I'm under geared for my set up so I'm looking for a good used 3.89 set as well. In north Phoenix, Az.