Can someone explain to me.....
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From: Rochester, Michigan
Can someone explain to me..... When you talk about the rear end breaking with a 4:10, what exactly breaks? Also, what makes the 12 bolt stronger than the 10 bolt? Are the 12 bolts ring & pinion gear bigger, allowing for stonger teeth than the 10 bolt. And is the teeth on either the ring or pinion that breaks on the 10 bolt?
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From: Chi-Town, IL
Re: Can someone explain to me..... I do not know much about the 12 bolts but when the stock torsen "explodes" all the spyder gears go, making it undriveable...eaton posi's really "break"...auburn posi's will go "one legged" when they break...basically the internals of the 10 bolts are weak and the 12 bolts or 9"'s have a lot of upgraded stuff... <img src="gr_stretch.gif" border="0">
Someone else can fill in on all the details
Someone else can fill in on all the details
Re: Can someone explain to me..... Yes, the components in a 12-bolt are bigger and stronger. Let me start off by saying that a 12-bolt is so appropriately named because 12 bolts hold the ring gear to the carrier, NOT because there are 12 bolts holding the cover on. The same thing goes for a 10-bolt.
There are a few different things that can go wrong in a 10-bolt. 99.5% of the time, when someone is running 4.10's they typically strip the teeth off of the ring gear and/or pinion gear. The higher you go numerically the smaller the teeth get. You obtain a gear ratio by counting the # of teeth on the ring gear and dividing it by the # of teeth on the pinion gear. I've also seen twisted axles. The stock units are crap, and a lot of power can twist them easily. Right after my friend's 422 cid was built, he still had the 10-bolt w/ 3.73's. On the 2nd pass with ET Streets, he twisted the left axle in 1/2. You can also have the posi problems mentioned above.
Don't think that you're home-free when you get a 12-bolt or 9". They can have their problems, too, but they'll take a LOT more abuse compared to a 12-bolt. I had a Strange 12-bolt in my '98 T/A, and my HD 33-spline Eaton posi broke after 3,500 miles. The spider gears shattered on a launch. I had changed gears just prior to this, and a lot of metal shavings were found floating around. I call Eaton up, and they told me that it only has a 6-month warranty. He also said that even if I was within the warranty period that they wouldn't cover it because I was running slicks. <img src="images/icons/rolleyes.gif" border="0">
There are a few different things that can go wrong in a 10-bolt. 99.5% of the time, when someone is running 4.10's they typically strip the teeth off of the ring gear and/or pinion gear. The higher you go numerically the smaller the teeth get. You obtain a gear ratio by counting the # of teeth on the ring gear and dividing it by the # of teeth on the pinion gear. I've also seen twisted axles. The stock units are crap, and a lot of power can twist them easily. Right after my friend's 422 cid was built, he still had the 10-bolt w/ 3.73's. On the 2nd pass with ET Streets, he twisted the left axle in 1/2. You can also have the posi problems mentioned above.
Don't think that you're home-free when you get a 12-bolt or 9". They can have their problems, too, but they'll take a LOT more abuse compared to a 12-bolt. I had a Strange 12-bolt in my '98 T/A, and my HD 33-spline Eaton posi broke after 3,500 miles. The spider gears shattered on a launch. I had changed gears just prior to this, and a lot of metal shavings were found floating around. I call Eaton up, and they told me that it only has a 6-month warranty. He also said that even if I was within the warranty period that they wouldn't cover it because I was running slicks. <img src="images/icons/rolleyes.gif" border="0">
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