9 inch OR 12 bolt
Thread Starter
Joined: Dec 2003
Posts: 490
Likes: 1
From: Burlington, Ont. / North Van B.C.
9 inch OR 12 bolt I was reading a post on here about transmisions, by Jaboriski. In the post it said an automatic gets 12 bolt and manual gets 9 inch. Can anyone tell me why ? Also, would having a 12 bolt with a T56 manual suck ?
thanks
thanks
There's no rule that a certain transmission has to get a certain rear. But the 9 inch with a spool is stronger than the 12 bolt. However, it is heavier and driving around on a spool is not ideal for the street. Since an automatic transmission is a lot easier on the rear, there is no need to get anything stronger than a 12 bolt.
Plenty(in fact most) people with m6's get a 12 bolt when they upgrade the rear. There is no problem with it, especially if you drive around on the street. However, it is more likely to break. I have a 12 bolt, but if it ever breaks i'll probably go all the way and get a 9 inch. The only problem is that it's a pretty expensive decision and you want to make sure you make the right one. You have to decide whether the driveability and lighter weight of the 12 bolt is worth sacrificing the extra strength of the 9 inch.
Plenty(in fact most) people with m6's get a 12 bolt when they upgrade the rear. There is no problem with it, especially if you drive around on the street. However, it is more likely to break. I have a 12 bolt, but if it ever breaks i'll probably go all the way and get a 9 inch. The only problem is that it's a pretty expensive decision and you want to make sure you make the right one. You have to decide whether the driveability and lighter weight of the 12 bolt is worth sacrificing the extra strength of the 9 inch.
I have a 12 bolt. If I could go back I would go 9". Clutch dumps on slicks is hard on any rear. A 9" will take a manual's abuse much better. Not to mention there are alot more choices for your carrier/posi type if your not going spool. Ever time I go to the track w/ the 12, it gets loud(gear noise). Just a little, it's noticable. Not bad has prolly over 10K on it.I drive it w/ street tires for a little, change the fluid, it quiet's down.
i went 9" with my m6 and never looked back. you can usally keep the rear quiter too . not to mention alot more options. and swap gears to what ever you need or want to. you could even run one setup for the track and another more streetable posi unit for the street. im running a locker and put 10-12k a year on my car . at the time both were about the same price when optioned out so i went the stronger route
if you dont have traction control (3ch abs) then you will lose the abs with a 9"
if you dont have traction control (3ch abs) then you will lose the abs with a 9"
9" all the way. However you CAN make the abs work with 3ch abs. What you have to do is machine down the carrier on the 9" so your reluctor wheel off the 10bolt will press on. Then you just have to mount the reluctor wheel sensor in the 3rd member casing. Thats what I did with the help of a good buddy of mine (LS1Joe). Abs still works and i got the 9".
TECH Enthusiast
Joined: Apr 2004
Posts: 749
Likes: 0
From: Chandler, Arizona
Originally Posted by Turnin'LT4
9" all the way. However you CAN make the abs work with 3ch abs. What you have to do is machine down the carrier on the 9" so your reluctor wheel off the 10bolt will press on. Then you just have to mount the reluctor wheel sensor in the 3rd member casing. Thats what I did with the help of a good buddy of mine (LS1Joe). Abs still works and i got the 9".
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Originally Posted by 02 Camaro SS
There's no rule that a certain transmission has to get a certain rear. But the 9 inch with a spool is stronger than the 12 bolt. However, it is heavier and driving around on a spool is not ideal for the street. Since an automatic transmission is a lot easier on the rear, there is no need to get anything stronger than a 12 bolt.
Plenty(in fact most) people with m6's get a 12 bolt when they upgrade the rear. There is no problem with it, especially if you drive around on the street. However, it is more likely to break. I have a 12 bolt, but if it ever breaks i'll probably go all the way and get a 9 inch. The only problem is that it's a pretty expensive decision and you want to make sure you make the right one. You have to decide whether the driveability and lighter weight of the 12 bolt is worth sacrificing the extra strength of the 9 inch.
Plenty(in fact most) people with m6's get a 12 bolt when they upgrade the rear. There is no problem with it, especially if you drive around on the street. However, it is more likely to break. I have a 12 bolt, but if it ever breaks i'll probably go all the way and get a 9 inch. The only problem is that it's a pretty expensive decision and you want to make sure you make the right one. You have to decide whether the driveability and lighter weight of the 12 bolt is worth sacrificing the extra strength of the 9 inch.
couldnt have said it any better my self...... but i kinda did the opposite.... i had a 6 speed with a 12 bolt but i was'nt running too fast like 11.8 at 119.... but then i went th400 and i got a 9 inch...(im planning on turning it into a full race car)... so i figured since i have to get a new drive shaft and all anyway now is a good time to switch..... but i think i even broke even on the deal with the selling and trading i did.......i sold my 12 bolt for 1950 brand new it was 2110..... this was over a year later and i got my 9 inch for 1995 shipped..... and i traded my 6 speed with Mcleod twin disc for the whole th400 swap...( tranny ,convertor,shifter, cooler,reverse manual VB, trans brake...ect).. and i love it i couldnt be happier i like my 9 inch alot more though b/c i havent broken anything since...... i broke like 4 torque arm with the 12 bolt......read the disclaimer on mosers web site if u r unsure what im talking about
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