BigSteele

iTrader: (17)

Ive been trying to search and read everything about replacing my rear end.
I hear a lot about how the 12 bolt posi is weak, but exactly how weak?
what I want to know is how strong the Eaton HD 33 spline setup is compared to the stock 10 bolt (torson) and a 9" posi/soft locker.
What type of setups/tq #s/situations would likely break the 12 bolt
I will be getting a new rear end pretty soon and Im stuck between the 12 bolt and 9"
I hear a lot about autos getting the 12 bolt but different things from M6 people.


Obvioulsy if i replace the rear end I dont want to worry about it breaking, so I want to know what are the situations where a 12 bolt would break. I dont want to get a spool so Im interested mainly in the posi strength.

My car isnt too much of a drag car but I would like to have some room in the future. I drive the car daily and need to make long trips on occasion. I like to shift hard and would like to be able to drop the clutch off the line.

Also, how much worse is the 9" for a daily driver compared to a 12 bolt. how bad are clearance issues and other problems
BTW I have ABS/TCS and plan to keep it

please share whatever info you know or experience on the subject

Thank You

1ScrudeDude

Nine Incher all the way. Get it with a locker.

The fact that you are M6, like to launch hard, plan for more power, and have a 4 channel set up, 'no brainer in my .02.....

I have a Strange 12 bolt, but with new sticky tires I think my HD Posi 33 spline will be terminated eventually. Which means I will have to go the spool route...which makes me wish I went with a Nine Inch

Steve Burger

iTrader: (33)

If I had to do it over, I would go 9". I am on the 2nd RP in the 12 bolt.

35thls1ss19

iTrader: (1)

i was curious about this too. If you didnt want the loud locker what do you do if you get a 9'' and what abotu abs? I have 3 channel

1ScrudeDude

Soft locker and ABS delete.

That's the predicament I was in too. I didn't want to 86 my ABS...

35thls1ss19

iTrader: (1)

you have a 12 bolt with a soft locker? how loud is it?

Armageddon

iTrader: (41)

I'm running a Moser 9" with a big Ol' fat spool. Drives like ****, but it gets the job done.

pwr2w8

Well if a person were to run a locker, would the 12 bolt survive around 550hp and tq?

I don't mean to hijack the thread but I'm curious.....

pwr2w8

of course I'm talking about a built 12 bolt here and an automatic, not exactly what the original post entailed.

Would there be any problems with that?

BigSteele

iTrader: (17)

From what I know I dont think anybody makes an "automatic" locker for the 12 bolt. (I think I saw a ARB air locker but thats a selectable one) I think its either the posi or a spool.

Thanks for all the imput!

those with the 9",
the stock driveshaft should fit with the iron center section right?
what about hitting the body
sorry for so many questions

Mark98SS

iTrader: (1)

I had minor clearance issues with the 9" & the true duals on Eibach Pro springs, went back to stock springs & no problem. Get the locker, I had a posi originally & it quit posi-ing after about 60 passes at the track. Have a locker now, it's noisy, pops & shudders here & there but gives differential action when needed & straight launches when you want 'em.

1ScrudeDude

No, sorry for the misunderstanding....I got a 12 Bolt instead of a 9 inch because of my 3 channel rear.

But now I wish I did get the Niner since I put sticky tires on.

I am told there is no locker for a 12 bolt, and a spool is our only "bullet proof" option.

silverZ98

iTrader: (6)

AMEN

pwr2w8

Sorry about the bad wording I meant that the rear would be behind an automatic, because you guys were talking about manuals. Just a misunderstanding, that's all.

BigSteele

iTrader: (17)

I was talking about the locker that works "automatically" vs say an electric one or air powered one that you have to switch either on or off. (maybe the term could be a "passive locker") While searching I think I found a locker (12 bolt) made by ARB but this would require an air compressor and more stuff. with that locker you have to either switch it locked or unlocked. I was saying that to my knowledge there is no locker available for the 12 bolt like you were probably thinking of.

I believe there are 2 types of lockers,
-those that are switchable from either an "open diff." to a "spool", such as the ARB air locker or other electric lockers
-and those that I have recently called "automatic" lockers that are like one-way units. the axles can "ratchet" and rotate faster than the carrier while taking a turn but they will allways be turned at least the speed of the carrier, such as the detroit locker or soft locker.

pwr2w8

ahhhhh okay now I see. Thanks for the info.

BigSteele

iTrader: (17)

I found this article, has some more info about the differences between the two
http://www.chevyhiperformance.com/te...les/0304_nine/

BOWTIE

Well I am going to have to go against the grain on this one. I was having this debate myself when I broke the stocker and decided to go the bullet proof route and went with a Billingsley Racing street 9" with locker. This included a Moser 9" housing, 35 spline axles, with a Strange center section with a 35 spline locker (not to be confused with a 31 spline soft locker) and 4.11's. This combination has ruined my car. I used to have a 2nd gen with a 12 bolt, spool and 4.56's and it drove better than this car does. I still have a feeling my locker may be defective, but have not had a chance to verify this with an expert (or at least someone that can convince Strange or Tratech that the unit is defective). In addition, the attachments on the Moser housing are off and required some considerable tweaking of adjustable components to get this thing even driveable. If I had to do it again, I would go with a Strange 12 bolt. If I had to go 9" I would have started with a Billingsley fabbed housing and then roll the dice on the center section; either try another 35 spline locker (since other people do not seem to have the problems I do perhaps I just have a bad unit), or go with a spool, or maybe even take a step backwards and go with 31 spline axles and a soft locker. Anyway, whatever you decide good luck.

matts22

iTrader: (2)

I'm going 9 inch, 31 spline soft locker when I am ready to upgrade. I'm buying it from Billingsley and I'll probably drive up there (5 hours) and have him install it, so I have nothing to worry about.

FANTAZ28

iTrader: (2)

i got a strange 12 bolt with the upgraded posi!
i launch at 4500 off a trans brake with the nitrous on!!!!
60's low 1.4's all day long and yet to have a problem and on the street i dont even notice the diffrence