^^ nah, it's only a couple of hours old now

 

I looked into those gears a little more, and it seems like its the motive 3.90 that are noisy, even when professionally installed.

 

hmm I did order Motive but think they're 3.89 if that makes any difference. I thought Motive gears were supposed to be more quiet than most of the rest. I guess I'll see after they are professionally installed. Does the rear have to be broken in if only the gears are being replaced? The Eaton truetrack is the same just getting different gears and axles too actually.

 

maybe thats why its a 3.89 and not a 3.90

 

3.70 gears are almost always quieter than the 3.89 gears in a nine inch, it doesn't seem to matter who the manufacturer is. Bob

 

I will be going with a 9" when mine goes.

 

9"......
Only way to go when you're laying down some serious Power!

 

this thread is seriously like 4 years old. i have gone 12 bolt because I just cruise my car.

 

Well considering I just blew my 12 bolt to pieces, I say 9" for an M6, auto's are easy on parts...

destroyed the pinion, ring gear, diff, and a bearing cap, and I have an aluminum cover w/preload.

I just built a narrowed 9" for not that much money using some really great stuff moser alum case, Strange 35 spline axles, spool, once it's assembled, and painted I'll post some pics...

 

GO WITH 9. I have a 12-bolt and it makes so much noise I cant listen to the radio. Moser told my installer to go **** off when we tride to explain to them something was wrong with the unit.

I HATE MOSER 12-BOLT. In Fact I'll NEVER PURCHASE FROM MOSER EVER AGAIN and I HOPE YOU DON'T ETHER!

 

Screw a 9". I'm going with an S60. The weight difference is negligable and you gain the ET difference back by having a rear with the hypoid offset closer to center.

 

FTR. You are also losing SOME small amount of power due to the more massive ring & pinion.

 

im installing my moser 9 inch right now and yes there is some tweaking , my uni panharde bar is adjusted all the way out and was 8th inch off the hole so i had to put a reamer to the hole but most people dont have a $260 reamer laying around , im an iron worker so it helped , and my stock rear sway bar is hitting the back of the mount for the torque arm , but all in all its a beafy rear and its good to do some work your self but for the price we shouldnt have to do anyting but bolt it up and fill it up , but as companies get bigger and the mass produce stuff , it tends to get sloppy , not saying that about anyones business but you get the point