When will my 10 bolt break?

**TransAmX2** · 09-20-2010, 06:00 PM

I found this article interesting, feel free to chip in your 2 cents, I'm not sure it will change anyone's opinion but it's an option I haven't heard mentioned yet.

http://www.gmhightechperformance.com...aul/index.html

**pajeff02** · 09-20-2010, 06:02 PM

Originally Posted by TransAmX2

I found this article interesting, feel free to chip in your 2 cents, I'm not sure it will change anyone's opinion but it's an option I haven't heard mentioned yet.

http://www.gmhightechperformance.com...aul/index.html

I posted a thread on this when I originally read the article in GMHTP. Can't believe they wasted the time and effort building a 10 bolt, despite their attempt at a logical explanation.

**Wesman** · 09-20-2010, 08:20 PM

Originally Posted by pajeff02

I posted a thread on this when I originally read the article in GMHTP. Can't believe they wasted the time and effort building a 10 bolt, despite their attempt at a logical explanation.

You act as if the stock rear is inherently defective. This is not the case. Its merely undersized for the output of our engines. When properly set up with good quality components, it will last damn near forever as long as you don't exceed its torque handling capabilities.

So if you're running over 400ft/lbs of torque at the wheels, do high RPM launches, or run slicks, the 10 bolt is not for you. Its not going to last at least. But for people who street drive their cars and don't launch them, fixing the 10 bolt is a much more cost effective option than shelling out $3000 for a 12 bolt or 9 inch rear that doesn't always fit properly, requires chassis and driveshaft modifications, and increases weight.

**bberretta** · 09-20-2010, 09:48 PM

Originally Posted by Wesman

You act as if the stock rear is inherently defective. This is not the case. Its merely undersized for the output of our engines. When properly set up with good quality components, it will last damn near forever as long as you don't exceed its torque handling capabilities.

So if you're running over 400ft/lbs of torque at the wheels, do high RPM launches, or run slicks, the 10 bolt is not for you. Its not going to last at least. But for people who street drive their cars and don't launch them, fixing the 10 bolt is a much more cost effective option than shelling out $3000 for a 12 bolt or 9 inch rear that doesn't always fit properly, requires chassis and driveshaft modifications, and increases weight.

I have a posi unit sitting in my garage that's split that'll disagree with you.

My car is not much above stock and I'm not out drag racing. I've done a few hard launches and did a fresh rebuild on the rear less than a year ago. I basically built the rear the exact same way GMHP did minus the Eaton unit (including the aluminum cover and bearing cap studs).

Think about it, it's basically the same size rear end that they put in a 4 cyl S10 that puts out less than a third of the power. Even the 8.2" rear from the '70's was considered "small" and you were better off upgrading to an 8.5" 10 bolt or better yet, a 12 bolt.

If you were to keep the car mostly stock, never drive it hard, and maintain it properly, sure the rear could last. It's not inherently defective, it's just by nature too weak for the power these cars are capable of pushing out. Unfortunately I can't think of anyone who buys a car like this and just putters around town in it, so finding viable options for upgrading and improving upon a weak spot in the car is the goal of every muscle car enthusiast.

**pajeff02** · 09-21-2010, 02:21 AM

Originally Posted by Wesman

You act as if the stock rear is inherently defective. This is not the case. Its merely undersized for the output of our engines. When properly set up with good quality components, it will last damn near forever as long as you don't exceed its torque handling capabilities.

So if you're running over 400ft/lbs of torque at the wheels, do high RPM launches, or run slicks, the 10 bolt is not for you. Its not going to last at least. But for people who street drive their cars and don't launch them, fixing the 10 bolt is a much more cost effective option than shelling out $3000 for a 12 bolt or 9 inch rear that doesn't always fit properly, requires chassis and driveshaft modifications, and increases weight.

Sorry, I should have clarified. The car they are installing the 10 bolt in is named "STi Killer". It is supposed to be a double duty track car with a hopped up engine and sticky tires. Hence the futility of their efforts.

**Wesman** · 09-21-2010, 11:01 AM

Originally Posted by pajeff02

Sorry, I should have clarified. The car they are installing the 10 bolt in is named "STi Killer". It is supposed to be a double duty track car with a hopped up engine and sticky tires. Hence the futility of their efforts.

Gotcha.

**Wesman** · 09-21-2010, 11:02 AM

Originally Posted by bberretta

I have a posi unit sitting in my garage that's split that'll disagree with you.

My car is not much above stock and I'm not out drag racing. I've done a few hard launches and did a fresh rebuild on the rear less than a year ago. I basically built the rear the exact same way GMHP did minus the Eaton unit (including the aluminum cover and bearing cap studs).

Think about it, it's basically the same size rear end that they put in a 4 cyl S10 that puts out less than a third of the power. Even the 8.2" rear from the '70's was considered "small" and you were better off upgrading to an 8.5" 10 bolt or better yet, a 12 bolt.

If you were to keep the car mostly stock, never drive it hard, and maintain it properly, sure the rear could last. It's not inherently defective, it's just by nature too weak for the power these cars are capable of pushing out. Unfortunately I can't think of anyone who buys a car like this and just putters around town in it, so finding viable options for upgrading and improving upon a weak spot in the car is the goal of every muscle car enthusiast.

What posi unit did you break?? A stock Auburn or Torsen?? They are not as strong as aftermarket units.

If you upgrade to a Detroit locker, Eaton Posi, or Detroit TrueTrac, there should be no issues with the differential.

**bberretta** · 09-21-2010, 03:29 PM

Originally Posted by Wesman

What posi unit did you break?? A stock Auburn or Torsen?? They are not as strong as aftermarket units.

You can say that again! Imagine the look on my face when I saw a crack all the way across the stock Auburn unit. I was like

and then I was like

and then I felt really stupid for having spent nearly a grand to rebuild my rear. I still have the Moser aluminum cover and bearing cap studs- might put them up on the classifieds with a few other items I have floating around. Sure, rebuilding the stocker is fine for some, but there's something about my right foot that tends to make it hit the floor.

**blackSS01** · 09-21-2010, 05:51 PM

I'll make this very easy for everyone:

The 10 bolt will break when it breaks!

Some people break them off the factory floor, some have went 10's!

flyinpastu · 10-10-2010, 12:36 PM

I didnt read all the pages here but my rear end didnt break yet but i want to re do the hole drive train and im looking to see what the best rear end is for a cheaper price i see that people like the 12 bolt rear end where do i get it and how much will it run me for the 12 bolt with 4:10 gears ?

**bberretta** · 10-10-2010, 02:48 PM

How much do you want to pay?

Seriously, depending on what options you get a new rear can run anywhere between a couple of grand to $4-5k. Then you'll need to sort through all the opinions to figure out which one you want to go with (9", S90, or 12-bolt.) Any way you go will be better than the 10-bolt that's in there!

**383ls6** · 03-10-2011, 04:21 PM

okay i tried to "beef" up my rear axle. eaton posi,moser forged axles,richmond. it lasted 1 year. just a fluke i thought. spent $800 to replace the ring and pinion. 1 year later grinding again. another $800 bucks. 9 months this time. with only 323 rwhp. wish i wouldve gotten the 12 bolt to begin with.

exactly what problems are there with the 12 bolt as my new assy. is in the mail?

**bberretta** · 03-12-2011, 08:24 PM

I can't speak for problems with the 12-bolt, but I can say that I've noticed nothing but improvements when I upgraded to a 9". I guess if I had to point out the negatives it would be weight (upgraded/larger rears are heavier) and I'm sure there is less clearance between the axle and the body (seem to hit the bumpstops more and I'm at stock height.) I guess you would be looking at how different companies set up the rear- some have said Mosers have been having problems but a guy that works at a shop I do side work at has a 12-bolt in his '97 and he hasn't had a single problem in the 5 years he's had it. Which 12 are you looking at getting?

**383ls6** · 03-13-2011, 05:20 AM

the moser/strange. i was mainly worried about the install. will it bolt right in with little or no mods?

**bberretta** · 03-13-2011, 02:33 PM

You're in luck! Here's the whole install with pics:

http://www.ls1.com/forums/showthread.php?t=20560

**383ls6** · 03-14-2011, 02:40 AM

kewl thanks

**Whamhammer** · 06-02-2011, 05:37 PM

Originally Posted by Wesman

But for people who street drive their cars and don't launch them, fixing the 10 bolt is a much more cost effective option than shelling out $3000 for a 12 bolt or 9 inch rear that doesn't always fit properly, requires chassis and driveshaft modifications, and increases weight.

At least the increased weight is in the "right" side to add the weight too. How much more weight does one expect to add tot eh car with a 12 bolt or 9 inch rear assembly??

**Cutlass** · 06-03-2011, 06:40 PM

Depends on axles and carriers...but I usually hear 25 to 50 pounds heavier for a 12bolt or 9 inch. If you need all the fancy adjustable suspension pieces to make it fit well...that adds weight over the stamped steel factory pieces. Of course if you were already gonna upgrade those suspension pieces anyways, it wouldn't matter

**Wesman** · 06-05-2011, 12:49 PM

Originally Posted by Cutlass

Depends on axles and carriers...but I usually hear 25 to 50 pounds heavier for a 12bolt or 9 inch. If you need all the fancy adjustable suspension pieces to make it fit well...that adds weight over the stamped steel factory pieces. Of course if you were already gonna upgrade those suspension pieces anyways, it wouldn't matter

And thats just for the 12 bolt and 9"...the Dana 60 option is a monster, quite a lot heavier than a stock 10 bolt.

**Firebirdformula99** · 08-29-2011, 04:35 PM

hey guys i gota question my car makes a bang like something is slacking up when i down shift like when i come to a stop it like slams kinda i know for a fact its not the trans mount or the torque arm bushing or mount so i have to think its either my rear end or trans the posi locks up fine and will spin both tires so i dont think its my limited slip its really pissin me off i been trouble shooting it for a week and it seems to be getting worse it also does it at low speed shifts or when the car has almost no gas in it or if the ac is on