View Full Version : 10 bolt, 12 bolt, 9 inch


71-Camaro-98
05-16-2008, 04:01 AM
What exactly is the difference between the 10 bolt, 12 bolt and 9 inch rear ends?? Are there any exterior differences so that you can tell which is which w/o opening them up?

jmm98LS1
05-16-2008, 09:45 AM
TONS of differences! The 10 bolt and 12 bolt rears can be identified by the respective number of bolts on the differential cover. The 9" notable feature is it's removable 3rd member (or "center section"). Here's some pictures:

My old stock 10 bolt (w/TA aluminum cover)
http://i85.photobucket.com/albums/k57/jmm98ls1/9%20inch%20swap/rear001.jpg

My Moser 9"
http://i85.photobucket.com/albums/k57/jmm98ls1/9%20inch%20swap/rear009.jpg

and a Moser 12 bolt
http://www.dw-zone.com/12bolt/12boltrear.jpg

fastz99
05-16-2008, 12:26 PM
TONS of differences! The 10 bolt and 12 bolt rears can be identified by the respective number of bolts on the differential cover. The 9" notable feature is it's removable 3rd member (or "center section"). Here's some pictures:

My old stock 10 bolt (w/TA aluminum cover)
http://i85.photobucket.com/albums/k57/jmm98ls1/9%20inch%20swap/rear001.jpg

My Moser 9"
http://i85.photobucket.com/albums/k57/jmm98ls1/9%20inch%20swap/rear009.jpg

and a Moser 12 bolt
http://www.dw-zone.com/12bolt/12boltrear.jpg

How bad is the install for the Moser 9in? Does it just bolt in?

EvoWake
05-16-2008, 12:49 PM
well.. simply put, the difference of greatest significance is the actual size of the ring and pinion gears... in a 12 bolt, a 9", or a dana, the gears are much larger, (and therefore can withstand greater stresses) than the stock 10 bolt

skeels
05-16-2008, 01:14 PM
Yes, it will bolt right in. Go to the gears and axels section for more info. Dozens of topics there. And im sure Bob at EPP will be all over you and help you any way needed.

71-Camaro-98
05-16-2008, 03:02 PM
Are there any aftermarket diffs that are considered better than others or is it all personal preference?

dschmittie1
05-16-2008, 03:13 PM
The 9in rear is all in all the strogest of the 3. Being that you have a M6 if you plan on putting some sticky tires on it and going to the track a 9inch is in your best interest.

DWZ28
05-16-2008, 03:37 PM
Differance internaly is ring gear size

F-body 10 bolt- 7.5"
12 bolt - 8.875"
9" - 9"
Dana 60 - 9.75"

but yeah from the outside just count the bolts on the cover or on the nine inch the front of the center section comes off

blue98Z
05-16-2008, 03:44 PM
Just don't confuse the 9" with a 8". They also have a removeable third member, but are smaller in size. Just wanted to clarify that for the untrained eye looking for a third member only.

landonew
05-16-2008, 03:49 PM
9" > 12 bolt > 10bolt

I got the 9", but gear noise sucks. Probably just the install though.

thunderstruck507
05-16-2008, 05:17 PM
the 12 bolt is very strong though and will waste less HP than a 9in, so it really depends how hard you want to be on it, I believe it also weighs less

bww3588
05-16-2008, 05:45 PM
Dana 60 is bigger than the 9 inch and is cheaper. plus you can keep your ABS and ASR/TCS. its also cheaper. little stronger than the 12 bolt, but not as strong as the 9inch.

71-Camaro-98
05-16-2008, 05:52 PM
How much does a new 9" or 12 bolt cost?

melchoir
05-16-2008, 06:20 PM
Dana 60 is bigger than the 9 inch and is cheaper. plus you can keep your ABS and ASR/TCS. its also cheaper. little stronger than the 12 bolt, but not as strong as the 9inch.

Are you sure? I was under the impression that an S60 is as strong, or stronger than a 9".

bww3588
05-16-2008, 06:44 PM
Are you sure? I was under the impression that an S60 is as strong, or stronger than a 9".

positive, the 9 inch having the 3rd member and not a traditional carrier like the D60 has, makes it a little stonger.

Soul TKR
05-16-2008, 07:22 PM
Are you sure? I was under the impression that an S60 is as strong, or stronger than a 9".

i was under the same impression...

demonpixel
05-16-2008, 07:59 PM
Yes, it will bolt right in. Go to the gears and axels section for more info. Dozens of topics there. And im sure Bob at EPP will be all over you and help you any way needed.

There are rumors that you may have to cut up the body in order to make the Moser 9" fit, and that the torque arm has tunnel clearance issues.

so I gotta ask...how much truth is there to that?

landonew
05-16-2008, 08:46 PM
There are rumors that you may have to cut up the body in order to make the Moser 9" fit, and that the torque arm has tunnel clearance issues.

so I gotta ask...how much truth is there to that?

simply not true. my bolted right in.

ssfast99
05-16-2008, 09:16 PM
yah my 9" from moser bolted up just fine, and yes because the ring gear is not secured by main caps in the 12 bolt and dana 60 setup it can take a sudden impact better, if it is for daily driving get a 12 bolt, if you want to make power with a m6 and launch the hell out of it you need a 9".

on a 9" if you will drive on the street people like the truetrak, where if it is a strip car the spool is way stronger, i drive my spool 9" with 27" tall et streets on the street once a week and have no problems.

on a 12 bolt just get the posi for street and a locker for the strip.

weight between the two is stupid sense the weight you add is over the wheels where you want the weight anyways.

ynkssws6
05-16-2008, 10:15 PM
How much does a new 9" or 12 bolt cost?

about 2500 all said and done, but while you're dropping the rear you mine as well change the fuel pump if you plan on doing some big mods later on.

slowjoe99
05-17-2008, 02:14 AM
weight between the two is stupid sense the weight you add is over the wheels where you want the weight anyways.

its unsprung weight and will not help on launch. A moser 12 bolts weighs 47 lbs more than the stock 10 bolt I think

SCREAMIN
05-17-2008, 08:53 AM
Yea 40-50 Lbs sounds about right, depending on which differential you got and rear end cover. Ive had my 12 bolt for 2 years now with plenty of abuse and no problems what so ever

Shooter_Jay
05-17-2008, 11:19 AM
What exactly is the difference between the 10 bolt, 12 bolt and 9 inch rear ends?? Are there any exterior differences so that you can tell which is which w/o opening them up?

Don't believe the hype about the 10bolts being weak.

Many people, stock and some mods, have well over 100,000 hard driven miles on their stock 10-bolts with zero problems.

The discussion has happened many times on here. Also, fyi, mine is a hard driven m6 with 101k miles on it.

The guys that break 10 bolts are the guys that put drag radials or slicks on them with high hp, and launch at high rpm.

Also, running a larger rear will actually cost you performance and power due to the extra power it takes to spin the heavier parts. Think about a fly wheel in a kids toy car. That little light car, think of how hard it is to push it forward relative to the light weight of the toy, because you are spinning up a weight, which takes a lot more energy than just moving the same weight a direction without spinning it also. I hope that made sense to readers.

Shooter_Jay
05-17-2008, 11:25 AM
well.. simply put, the difference of greatest significance is the actual size of the ring and pinion gears... in a 12 bolt, a 9", or a dana, the gears are much larger, (and therefore can withstand greater stresses) than the stock 10 bolt

Also, from what I understand, where the pinion rides on the ring gear, which is why the ford 9" is so much stronger than the ford 8.8", the 8.8 lines up like O--- where the 9" lines up lik O___. probably more to it than that, but just trying to give as much info as possible.

01ssreda4
05-17-2008, 12:35 PM
my ten bolt has held up for 100k and works great. on the day it bites it, i will prolly go the 12 bolt route bc i will never own slicks. at least not for this car.

araber89
05-17-2008, 03:17 PM
Only 2500 bucks. Wow I was always under the impression it was like twice as much. Also what is about the limit a 12 bolt can hold horse power wise. Like Horse Power+Slicks=? Where will the 12B brake?

chvycmaroz28
05-19-2008, 12:15 AM
12 bolt dumdumdum

2001z
05-27-2008, 07:35 PM
Don't believe the hype about the 10bolts being weak.

Many people, stock and some mods, have well over 100,000 hard driven miles on their stock 10-bolts with zero problems.

The discussion has happened many times on here. Also, fyi, mine is a hard driven m6 with 101k miles on it.

The guys that break 10 bolts are the guys that put drag radials or slicks on them with high hp, and launch at high rpm.

Also, running a larger rear will actually cost you performance and power due to the extra power it takes to spin the heavier parts. Think about a fly wheel in a kids toy car. That little light car, think of how hard it is to push it forward relative to the light weight of the toy, because you are spinning up a weight, which takes a lot more energy than just moving the same weight a direction without spinning it also. I hope that made sense to readers.

Im sorry but i have to diasagree the 10bolt is very weak and i broke mine on drag radials with a less than agressive launch when i had almost stock power! I think it is a waste of money to try to build a 10 bolt when you know it is gonna break again especially if you want to drag the car in a manual. I know plenty of people that have rebuild theres more than once and they spent a fortune just to break again and again with less than 400 to the rear on drag radials. My brother broke his on and auto on street tires with his only mod being a lid!! All you have to do is hit the search button on here to see the carnage that people have had with the stock 10 bolts. Just my .02

2001z
05-27-2008, 07:37 PM
Only 2500 bucks. Wow I was always under the impression it was like twice as much. Also what is about the limit a 12 bolt can hold horse power wise. Like Horse Power+Slicks=? Where will the 12B brake?

Rule of thumb 12bolt=auto 9in/dana60= m6 cars . Just from what i have read and personally i love my 9in fromt driveline solutions.

landonew
05-27-2008, 07:45 PM
Don't believe the hype about the 10bolts being weak.

Many people, stock and some mods, have well over 100,000 hard driven miles on their stock 10-bolts with zero problems.

The discussion has happened many times on here. Also, fyi, mine is a hard driven m6 with 101k miles on it.

The guys that break 10 bolts are the guys that put drag radials or slicks on them with high hp, and launch at high rpm.

Also, running a larger rear will actually cost you performance and power due to the extra power it takes to spin the heavier parts. Think about a fly wheel in a kids toy car. That little light car, think of how hard it is to push it forward relative to the light weight of the toy, because you are spinning up a weight, which takes a lot more energy than just moving the same weight a direction without spinning it also. I hope that made sense to readers.

Really??? Cause mine broke during daily driving. Just got in the car one day, and bam!!! Hopefully your 10 bolt lasts you a long time, but don't tell me they are strong cause.... they ain't!

71-Camaro-98
05-27-2008, 08:19 PM
Well, if I am not mistaken mine is still the stock 10 Bolt and I am going on 108k and I haven't noticed any problems yet... Hope it stays that way.

2001z
05-29-2008, 06:54 AM
Well, if I am not mistaken mine is still the stock 10 Bolt and I am going on 108k and I haven't noticed any problems yet... Hope it stays that way.

Im guessing you dont take yours to the track much. There isnt a time limit on when they brake but if you drive your car hard and do it enough it will break.

Batass
05-29-2008, 04:20 PM
2500 bucks? lol, I paid half that. I got a moser 9" housing with axles for a thousand bucks, and a center section for 250 that included 4.11 gears and a spool all set up. I spent 1300 bucks. Its not too noisy either, but then I couldnt hear very well over the open headers and the neighbors bitching.

Gordon0652
05-29-2008, 04:32 PM
To the OP, do you plan on getting a new rear end, or just intrested in learning about them.
If you plan on buying one...
Everyone missed the biggest question:eyes:
What kind of power do you want to be making at the rear wheels?

Rule of thumb 12bolt=auto 9in/dana60= m6 cars . Just from what i have read and personally i love my 9in fromt driveline solutions.

Not true, if he has an auto and plans to be making 1000rwhp w/ sticky tires i would never throw a 12-bolt on the car, thats more of 9" and D60 territory.

71-Camaro-98
05-29-2008, 04:41 PM
To the OP, do you plan on getting a new rear end, or just intrested in learning about them.
If you plan on buying one...
Everyone missed the biggest question:eyes:
What kind of power do you want to be making at the rear wheels?





It was more out of curiosity and wanting to learn the difference between them.. I do plan on getting a new rear end at some point. I just dont know when. As for which one I would pick, I think I would just go with the 9". I am wanting around 400rwhp so I think that would do me fine...

What exactly is the difference between having a lower spline count vs a higher spline count??

Gordon0652
05-29-2008, 11:12 PM
It was more out of curiosity and wanting to learn the difference between them.. I do plan on getting a new rear end at some point. I just dont know when. As for which one I would pick, I think I would just go with the 9". I am wanting around 400rwhp so I think that would do me fine...

What exactly is the difference between having a lower spline count vs a higher spline count??


You say 400rwhp but that will get old after a while and you will want more.
Goodluck.

71-Camaro-98
05-29-2008, 11:23 PM
You say 400rwhp but that will get old after a while and you will want more.
Goodluck.

Thats why my 71 will have over 600rwhp :D

SOMbitch
05-30-2008, 11:01 AM
What exactly is the difference between having a lower spline count vs a higher spline count??


More splines = more strength