Gear marking compound barely shows pattern

[k72nova]

I have a ford 9 inch that developed a whine, I'll get to why in a minute. I'm reassembling the rear end and after putting gear marking compound on the gears the marks are barely visible. Is this OK? Why is it happening?


This is the pattern that I'm seeing, I've tried rotating the ring with a wrench, and using a drill on the pinion nut for 45 seconds, both of those with or without my hand resting on the ring/pinion for slight resistance. I've also tried thinning the marking compound but I can't get the marking to show any better.



This is a used ring/pinion but with only around 1,000 miles on them, I set the backlash to .008 which is what Motive Gear calls for but is that different for a used set of gears? I've heard it is but haven't had anyone tell me what the tolerance is. This is what the gears looked like when I disassembled the center section. Don't mind the dog hair from the rags...




A little backstory, I bought this center section from Quick Performance and the pattern looked good when I installed it, BUT my torque arm has a mounting surface that is installed over the pinion housing. I think what happened was during mock up I didn't use Loctite on the pinion bolts and they came loose. My rear end started to whine during deceleration while racing and when I got the car home and pulled the center, the pinion bolts were loose. My bad lesson learned, now I'm just a little stumped on why my marking are so faint. I appreciate any info you guys can give me and let me know if you need any more details.