backlash for 8 3/4

[zebber]

hey guys ,, does anybody know what the backlash is supposed to be on a 8 3/4 rear, my book has 2 figures and i don't know which one to use ..one is
.005 -.0015 and the other is .06 -.08 ??? which one do i use. .005-.0015 seems awful small the .05 -.08 sounds right but i'm not sure ,don't wanna do this twice. thanks

[moparking]

Since both of your sources show .005 to .006",shoot for that number.Rotate the ring gear and check it at about 6 places around the gear.You will find tight and loose spots around the ring gear due to carrier and gear manufacturing tolerances.Just make sure the tightest spot is'nt less than .005" Re-check the pattern after everything is set and tightened.

[937CHARGER]

.008 - .010 is what I would use on a new gear. If you are tightening up the backlash on an existing used gear setup , I would leave it alone as the gears are ware mated to each other and tightening the backlash may ruin it.

[djswwg]

As a footnote to 937charger's post, you're better off to have it a little on the loose side (8-10 thou) than tight, as these specs will tighten up as the diff warms up. If you get excessive "clunk" when you put the trans in gear, use 90W140 diff lube rather than the usual 75W90, and I'd consider an additive with heavy viscosity, such as Lucas, or equivalent. And use a synthetic, they are more viscosity stable.........djs

[tsteiner61]

Randy's Ring & Pinion has a downloadable instruction booklet in PDF format. In it, the backlash spec for a Mopar 8 3/4 rear end is listed as .006" - .010".