12 Bolt help needed quick
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From: Diamond Bar, CA
12 Bolt help needed quick I know this isn't in quite the right section, but I need some help pretty quick. Well after a little accident I had, it looks like I need to get a 12 bolt. I busted both of my axles and the shop says my auburn posi unit is shot and cannot be repaired. It would cost about $1500 to get a new auburn posi, 2 new axles and get her all buttoned back up....or I could just go with a 12 bolt for about $1k more.
What do you think?
Assuming I go 12 bolt, I need some direction on a few options:
1) Moser vs Strange? Any major differences?
2) Eaton Posi vs Full Spool? I don't know what a full spool is.
3) Upgrade to the 1350 series pinion yoke worth it?
4) Does the standard chrome comers usually have drain plugs? Do I need to worry about changing fluid often in a 12 bolt?
5) It is worth upgrading to a TA Cover?
6) Is it worth getting the 33 Spline posi/axles setup?
7) This is for a daily driver, so would 3.73 gears be my best option?
8) Will the shop need an installation kit for mounting up the sway bars, etc?
Sorry for all the questions, but I need to get my car back up and running so I need a quick education on 12 bolt systems. Thanks in advance for all your help!!!!!
What do you think?
Assuming I go 12 bolt, I need some direction on a few options:
1) Moser vs Strange? Any major differences?
2) Eaton Posi vs Full Spool? I don't know what a full spool is.
3) Upgrade to the 1350 series pinion yoke worth it?
4) Does the standard chrome comers usually have drain plugs? Do I need to worry about changing fluid often in a 12 bolt?
5) It is worth upgrading to a TA Cover?
6) Is it worth getting the 33 Spline posi/axles setup?
7) This is for a daily driver, so would 3.73 gears be my best option?
8) Will the shop need an installation kit for mounting up the sway bars, etc?
Sorry for all the questions, but I need to get my car back up and running so I need a quick education on 12 bolt systems. Thanks in advance for all your help!!!!!
I'll chime in with what I know:
The stock rebuild is not worth $1500 bucks. Stock 10-bolts go for around $400 bucks used for the complete axle. That's what I sold mine for when I got the 12-bolt. If you decide to get a 12-bolt:
1. I've got a strange. They were on sale when I needed one. A lot of people have moser, a lot have strange. Do a search to read more.
2. According to #7, it's a daily driver. You don't want a spool. Spools lock the axles together, not allowing the outside wheel to speed up around a turn (like a regular differential). Spool is lighter and stronger for drag racing, but I wouldn't recommend one in a daily driver unless you are "hardcore" or a "poser"
3. yes.
4. I don't know. I got the standard strange cover. I changed the oil once after break-in.
5. Again, I've got the standard strange cover
6. I'd say yes if: 1. you are going to see a lot of track time, a lot of hard launching. OR 2. if you are going to increase your power levels (head/cam, power adder, etc)
7. I vote 4.10s. I drive my car ~3 days per week during spring/summer/fall, about 300-400 miles per week. 4.10s are great, I'm even considering more gear! Part throttle drive-ability is great, and wide open throttle is great.
8. I didn't. I just used some scrap steel to make the needed spacers. You could buy the kit to make it easier, or the shop could make some spacers.
Also, try searching around the forum (you probably already have)
Good luck!
The stock rebuild is not worth $1500 bucks. Stock 10-bolts go for around $400 bucks used for the complete axle. That's what I sold mine for when I got the 12-bolt. If you decide to get a 12-bolt:
1. I've got a strange. They were on sale when I needed one. A lot of people have moser, a lot have strange. Do a search to read more.
2. According to #7, it's a daily driver. You don't want a spool. Spools lock the axles together, not allowing the outside wheel to speed up around a turn (like a regular differential). Spool is lighter and stronger for drag racing, but I wouldn't recommend one in a daily driver unless you are "hardcore" or a "poser"
3. yes.
4. I don't know. I got the standard strange cover. I changed the oil once after break-in.
5. Again, I've got the standard strange cover
6. I'd say yes if: 1. you are going to see a lot of track time, a lot of hard launching. OR 2. if you are going to increase your power levels (head/cam, power adder, etc)
7. I vote 4.10s. I drive my car ~3 days per week during spring/summer/fall, about 300-400 miles per week. 4.10s are great, I'm even considering more gear! Part throttle drive-ability is great, and wide open throttle is great.
8. I didn't. I just used some scrap steel to make the needed spacers. You could buy the kit to make it easier, or the shop could make some spacers.
Also, try searching around the forum (you probably already have)
Good luck!
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Great, thanks for the response.
Is there a drain plug on your strange housing?
I'm gonna do the 33 splines just because it is only $100, might as well do it.
I think 4.10s are going to be too much for a cruiser that will only see moderate track time and I currently more of a comfort car then a full street machine.
I have been leisurely searching around for info but I just found out about the need for a rear today
Can you think of anything else I am missing?
I have BMR Bolt on relo brackets on my stocker, I am not really lowered, but will I need any brackets for the 12 bolt to get a nice level or slightly downward angle on the LCAs?
Is there a drain plug on your strange housing?
I'm gonna do the 33 splines just because it is only $100, might as well do it.
I think 4.10s are going to be too much for a cruiser that will only see moderate track time and I currently more of a comfort car then a full street machine.
I have been leisurely searching around for info but I just found out about the need for a rear today
Can you think of anything else I am missing?
I have BMR Bolt on relo brackets on my stocker, I am not really lowered, but will I need any brackets for the 12 bolt to get a nice level or slightly downward angle on the LCAs?
Launching!
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From: Colorado Springs
I don't like spools on the street. Some guys aren't bothered by them, but the chirp-jerk..chirp-jerk is just too much for me in the grocery store parking lot. Look at a good locker if you want to tie up the rear end. Although they exhibit many of the same traits as a spool, some can be a little easier around town, but the lock/unlock and associated clunking and jerking is a little much for my taste in a street car. For a strip only car, I opt for a spool.
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Originally Posted by skytower31
Great, thanks for the response.
Is there a drain plug on your strange housing?
I'm gonna do the 33 splines just because it is only $100, might as well do it.
I think 4.10s are going to be too much for a cruiser that will only see moderate track time and I currently more of a comfort car then a full street machine.
I have been leisurely searching around for info but I just found out about the need for a rear today
Can you think of anything else I am missing?
I have BMR Bolt on relo brackets on my stocker, I am not really lowered, but will I need any brackets for the 12 bolt to get a nice level or slightly downward angle on the LCAs?
Is there a drain plug on your strange housing?
I'm gonna do the 33 splines just because it is only $100, might as well do it.
I think 4.10s are going to be too much for a cruiser that will only see moderate track time and I currently more of a comfort car then a full street machine.
I have been leisurely searching around for info but I just found out about the need for a rear today
Can you think of anything else I am missing?
I have BMR Bolt on relo brackets on my stocker, I am not really lowered, but will I need any brackets for the 12 bolt to get a nice level or slightly downward angle on the LCAs?
Yes, my strange housing has a drain plug. I'd definately ask that question before you purchase, you want a plug especially since you'll want to change the fluid after break in.
Right, 100 bucks for the axle upgrade is a no-brainer.
Hmm. I still recommend 4.10 gears. Even on a car that never goes to the track, I would get 4.10s. Even if I never raced, and never went full throttle. Just for cruising alone, I think 4.10s are the best. Freeway, 6th gear rpms are still low for cruising. And 6th is way more useful overall.
I'm not sure about the lca question. I just bolted up my axle, stock rideheight and stock locations.
-Dan
P.S. 4.10s are not too much!
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From: Diamond Bar, CA
I don't want to get stuck in the drone area of the GMMG in 6th gear. I get some good drone from 2000 to 2500 rpms so I wanna try and stay below those RPMs up to about 80 or so. With the stock 3.42s 80 mph is 1800 rpms. 3.73s puts me at 1950 rpms. 4.10s put me at 2150 rpms. I think the 3.73s will be just about right with my exhaust and sound needs 
Thanks for the opinions though!
Thanks for the opinions though! 
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Originally Posted by skytower31
I don't want to get stuck in the drone area of the GMMG in 6th gear. I get some good drone from 2000 to 2500 rpms so I wanna try and stay below those RPMs up to about 80 or so. With the stock 3.42s 80 mph is 1800 rpms. 3.73s puts me at 1950 rpms. 4.10s put me at 2150 rpms. I think the 3.73s will be just about right with my exhaust and sound needs Thanks for the opinions though!
Thanks for the opinions though! ive got four gears and 3.73
if i even had five,
you can be damn sure id get 4.10
you have six!!!
with 3.73 at 80mph im at like 3000rpm!
get the 4.10's and some dynamat or something like it to take car of exhaust noise.
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Originally Posted by Stone0fFire
ive got four gears and 3.73
if i even had five,
you can be damn sure id get 4.10
you have six!!!
with 3.73 at 80mph im at like 3000rpm!
get the 4.10's and some dynamat or something like it to take car of exhaust noise.
I appreciate opinions, but please don't give me ****.
If you could tryout 4.10s and any other gear like trying on clothes you would be standing at the checkout with a set of 4.10s under your arm. I'm just about ready to pull the 4.10s out of my two week old Moser 12 bolt and go to 4.30s, gotta love that double overdrive.
I have a LM and qtp headers, no drone. The cat's probably have something to do with it though. I've driven a M6 car with 3.73,s 3.90's, 4.10's, 4.30's and 4.56's. 4.56 is a little much for a stock car, 4.10 and 4.30 is good. Friend of mine did a g5x3 cam, and started off with his 12 bolt with 3.73.s Every time he took it to the track, he came home, said it needed more gear, and went up the next step. He got to 4.56 and went back to 4.30, with a 26 inch tire, it was too much. I am planning on going to 4.30's myself when I do the rear in my car this winter. Of course, I know where there's alot of gearset's sitting in a garage now