thechef

iTrader: (13)

i am thinking of going with a ford 9 inch rear for my car instead of the usual 12 bolts

what brand did you go with and is the rear end noisey???

i know alot of the 12 bolts are noisey and i was wondering how people are making out with the 9inches?

SPANKY LS1

iTrader: (24)

I have had both, neither was particularly loud, its all in the setup, IMO. My Moser 9" had both 3.70 and 4.11 gears, both were moderately loud, and the pinion seal leeked the whole time I had it. (3-4 seals), and it was HEAVY. My current Moser 12 bolt has 4.30 gears, and is pretty quiet. (Slight wine on coast side only) It was set up by Moser , then I had it checked by a local gear installer, and he said it looked good. Both bolted in without any issues, although the 9" seemed to raise the car ~3/4" to 1", while the 12 bolt maintained about the same ride height. IMO, I consider 9" more of a "race" rearend, and a 12 bolt more of a "street" rearend. The 9" was heavier and louder than my 12 bolt, but the 12 bolt was more expensive. Also, the 12 bolt will be more efficient than the 9" due it its pinion gear placement. I think the setup is more to blame for the amount of noise generated than which type of rearend is chosen, either one can be made reasonably quiet.


12 bolt versus 9" pros/cons

12 bolt has more posi choices than 9" do
12 bolt is more efficient than a 9"
12 bolt kept the car at the stock ride height -vs- the 9"
12 bolt is a GM product
9" has more gear ratio availibility, including OEM gears (quieter)
9" should be stronger than 12 bolt
9" has stronger axles (commercially available 35 and 40 spline) -vs- 33 for the 12 bolt
9" can be built cheaper (~$1600-$1800) -vs- nearly $2100-$2400 for 12 bolt

Freak

i have a moser 9 inch but I bought it without the center section, and built my own. ran that for a while, it was like an ambulance following me around. at 70 the radio was useless. (found out later that the gears I had were know for that)

this spring I had Reider Racing build me a new center and its very quiet, as with spanky i have a slight whine on coast, but not bad.

42NightZ28

Moser 9in, I am running a Ford 3.70 gear and it dosn't make a sound or leak(Other than the Detroit lockers normal sounds). It was set up by a friend.

MRI-TEK

I've got a Moser 9" . Very quiet rear , no whine at coast but the only prob. was the pinion seal was leaking. I had the seal replaced & new gears put in . The 9" has not leaked yet but I wouldnt be surprised if it did ,as this is a common problem with the 9" if it is not degreed with cutting the rear spring perches and re-welding the perches to correct pinion angle . I dont think I'm going that route !!

dark_angel

$1600 WHERE...

Fireball

iTrader: (21)

buy the housing/axles and piece out the center components carefully. Can be done for 1600

Pro Stock John

iTrader: (34)

I'm running a Moser 9" with a Strange center section.

Colonel

I had a Moser 9" with 3.89s. It was extremely noisy even after changing the gears out a few times. It also raised the car up a bit which I didn't like. To Moser's credit, they gave me a sweet deal on my 12-bolt and I've been happy ever since.

The ONLY way that I would run a 9" is if I needed to be able to change gear ratios often.

xaon

iTrader: (12)

Moser 9" here. My pinion seal leaks a little bit now, not a biggie to me. I've got 4.11 gears and a posi in the center section that moser installed.

I get a slight houl/clunking when going around a right hand 90-degree turn at low speeds, and the gears howl a little bit on decelleration from about 80mph to 55mph.

My rear end did raise the rear of my car up 3/4" to 1",

Vents

iTrader: (9)

another vote for the 9".

you guys are gonna hate me, but i ended up picking up a used housing, PT unit and axles in a trade for some parts, and i built a centersection w/ a solid shim kit, daytona support, and richmond gears all for about 350. not noisy at all, (all depends on the builder's prefrence on backlash, and pattern IMO) one leaky **** though. ;D