Which rear to buy? 12 bolt or 9inch
08-04-2003, 03:00 PM
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Re: Which rear to buy? 12 bolt or 9inch Moser 9 inch
which gear you want depends on what you have done to the car, and what you want out of it. I have 4.30's, but I think they would be a bit much in the 1/4 unless you ahve a raised rev limiter. but they are fun as all heck on the street
which gear you want depends on what you have done to the car, and what you want out of it. I have 4.30's, but I think they would be a bit much in the 1/4 unless you ahve a raised rev limiter. but they are fun as all heck on the street
08-04-2003, 03:31 PM
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Re: Which rear to buy? 12 bolt or 9inch I have full bolt ons and a tr 224 cam and going to get some heads soon
The car is an A-4 with a 3600 stal
What gear would be right for this?
Thanks
Rob
The car is an A-4 with a 3600 stal
What gear would be right for this?
Thanks
Rob
08-04-2003, 03:37 PM
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Re: Which rear to buy? 12 bolt or 9inch 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
, 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
08-04-2003, 03:45 PM
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Re: Which rear to buy? 12 bolt or 9inch well, having never owned a 12 bolt i cant quite vouch for that side, but i can say that my 9" is one leaky ****. man, what a pain. im going back with 2 gaskets and bath use sillicon next time. grr...
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08-04-2003, 05:24 PM
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Re: Which rear to buy? 12 bolt or 9inch My Moser 12 bolt wiht 3.73 was setup by a different company and it's quiet as the stock 10 bolt. It did raise my rear about 3/4" - 1" though. Not sure about 9" rears.
08-04-2003, 07:48 PM
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Re: Which rear to buy? 12 bolt or 9inch Depends on your power level, but I would look at that guy doing the 8.8's. I have one. It bolted right in, quiet, car sits as it did stock. You actually can't even tell it has a different rear unless you look REAL hard. Not a bad option to consider these days.
Scott
7.4@95...3550#'s
Scott
7.4@95...3550#'s
08-05-2003, 11:32 AM
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Re: Which rear to buy? 12 bolt or 9inch
Depends on your power level, but I would look at that guy doing the 8.8's. I have one. It bolted right in, quiet, car sits as it did stock. You actually can't even tell it has a different rear unless you look REAL hard. Not a bad option to consider these days.
Scott
7.4@95...3550#'s
Scott
7.4@95...3550#'s
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