8 3/4 489 gear pattern reading

[NoahSewal]

Im just looking for some input on my pinion depth reading as this is my first gearset change ive done. It's a 8 3/4 489 case with .030 shim and test bearings and no crush spacer installed with 3.91 gears. there's material left on the face and flank of the teeth so i wasn't sure if it was good or not. ive got pictures down below

 

[George Jets]

Looks like your pinion is too deep, rubbing the paint off the heal.

Also looks like the ring gear needs to be brought closer to the pinion, lash.

 

[413]

Yes what he said. Do you have the book open, it has good instructions. Factory service manual.

Where did you guys learn to put gear marking compound all the way around the ring gear? You only need to mark 5-6 teeth.

 

[Dana67Dart]

Where did you guys learn to put gear marking compound all the way around the ring gear? You only need to mark 5-6 teeth

Ya ya ya...

Some is good,
More is better,
Too much is just right!

 

[NoahSewal]

Yes what he said. Do you have the book open, it has good instructions. Factory service manual.

Where did you guys learn to put gear marking compound all the way around the ring gear? You only need to mark 5-6 teeth.

i only put it on 4-5 teeth ive just ran it around maybe 10 times so it's spread to most of the teeth

 

[NoahSewal]

Looks like your pinion is too deep, rubbing the paint off the heal.

Also looks like the ring gear needs to be brought closer to the pinion, lash.

View attachment 1715957669

ive been chasing my tail all day and i can't find the sweet spot. in the pictures down below ive got .045 shims but it looks like it's too much still. the initial pictures were at .030. ive tried .035 and .040 with no better result. you have any suggestions to what i should try different? im at .008-.010 backlash

 

[perfacar]

did you set pinion depth with a gauge?

 

[john-9]

make your pinion depth shim changes in .003 increments -- you are so close at .045 -- looks good as far as contact pattern on the drive side ( maybe a little low on the toe ) ,,coast side looks ok ,,so take .003 out go to .042 shim this should bring the drive side pattern up a bit to match the coast ,, check the pattern again if not happy try a .039 shim ,,, so your backlash setting is good ,, i like to keep it at the low end of spec .008 because as the bearings and gears run in backlash will open up three to five thou.