28 spline axles in 31 spline carrier - TCCoA Forums
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post #1 of 3 (permalink) Old 06-03-2010, 04:46 AM Thread Starter
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28 spline axles in 31 spline carrier

I have searched, but unable to find an answer. I have a 97 Cougar and can get a 3.73 gear set and 31 spline ls for free. Now, I have found by searching that the pin diameter is different on the 31s, but are the 28 spline side gears interchangeable with the 31s, or in other words can I use the 28 spline side gears with the 31 spline gears on the pin? Any help you can give would be great. I know the simple answer is get a 28 spline diff, but the price is right on this!
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post #2 of 3 (permalink) Old 06-03-2010, 05:25 AM
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You can use the 28 spline side gears, but they have to be for an IRS trak lok unit. If you currently have an open diff, you won't be able to just re-use your side gears. You are probably better off selling the complete 31 spline unit and buying a 28 spline IRS trak-lok diff.

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post #3 of 3 (permalink) Old 06-03-2010, 11:04 AM Thread Starter
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I actually work at a Ford dealership in Canada. I ordered the diff gears for a ls Cougar today with the hopes it may work. They were only $138, so if it works, it's gonna be a cheap way to go! Glad to hear from someone who thinks it will work! Thanks!
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