socmguy

iTrader: (18)

I'm sorry if this has been brought up a zillion times but the search is down and I've read all the stickys. Here's my question. I have a 2000 Z28 M6 and am installing 4.10s. I've been told that the proper backlash is around 8-12 thousanths. I hear that people tighten the ring and pinion up just a little more for manual cars and drag racing. I know a tighter backlash will cause more heat but will it be safer for a manual? Anyone smarter than me, please reply!

keliente

iTrader: (22)

I like to set up my M6 on the tight side. So if the manufacturer for your gear says .008-.012, I would go with .008.

monzaz

Well I go buy GM and I do not know of any GM gear set to anything over ..010. We do Muscle car diffs GM 10 bolt 12 bolt etc. and set them to .005-.008 New. Now Richmond gears seem ro let there gears go to .010. I noticed the gear pattern on most Richmond gears do not come out well under tight backlash. I usually ahve to loosen the backlash so I can get a clean pattern. Motive and Yukon you can get tight and still get a clean pattern also. Just my experiences.

Jim

socmguy

iTrader: (18)

The gears I bought are AAM. So I should set those at 8 thousanths?

mzoomora

iTrader: (36)

Probably more like 5 or 6.

GOaT Cheese

For hard drag race use, set them up at around .030 (yes, thirty), they will be noisey, but they will live.

TT632

iTrader: (3)

Hi GOat Cheese,
Are these trans brake launches? Seems like the ring gear would see a huge impact load with a large clearance.

SS SLP2

iTrader: (8)

before you begain to setup you need to know if the gear is 3 cut or 5 cut, I think the AAM is 3 cut, and I agree with Z200MORA if AAm, I would suggest .005 and set the pattern high, I set my AAM @ .005 and have no problem after 2 years, several trips at the STRIP, 1.60' in the 60 ft and a lot of street jumps
jusy my .02' , Johnny

MikeSomething

iTrader: (11)

5-10 thousandths...

mzoomora

iTrader: (36)

AAM are 2 cut gears.

JimsWS6

iTrader: (1)

I believe it depends on whether your using the old bearings or new also. I used my orginal bearings with 13k on them, with a new AAM 4.10 gears and set them to .005.

chicane

Above and beyond all else...

It is and has been a "rule of thumb" to use 0.001" for every inch of ring gear.

With that said, 7.5" would be 0.0075" or betwen 0.007 - 0.008"... unless specifically directed by the component manufacturer differently. But... remember, this is only a guide line. Even though the manufacturer says to use x.xxx" that itself is a guid line number as it does not take into account for housing irregularties.

I say set it up for 0.008" and and take a look at it. If it doesnt look like the way you want it... change it. Its that simple.

GOaT Cheese

That was our M6 setup, but that huge backlash actually cushions the gear teeth from impact. That extra 90 wt. that has to squeeze out of that large gap acts as a shock absorber. I have had excellent results with the 7.625 rear ends hitting them with a ton of power and they seem to hold up beyond anyones expectations. But, be forewarned, they are VERY noisey if street driven.

SS SLP2

iTrader: (8)

My mistake,MZOOMORA is correct, the AAM gear is 2 cut
try http://www.aam.com/file.php/255/axle+shaft+brochure.pdf and go to page # 41 for correct setup

GOaT Cheese

2 cut vs. 5 cut doesn't affect backlash a whole lot. You just need to read the gear pattern differently between the two.

socmguy

iTrader: (18)

Thanks to everyone that helped out. I bought the master install kit and replaced all bearings and seals. Set backlash at .008 and checked it in 3 places on the ring and they were all the same. Good pattern right down the center of the teeth as well. Thanks again to everyone!