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Jeep NP231 Transfercase Slip Yolk Eliminator - Monsterized NP231

Christian Hazel
| Brand Manager, Four Wheeler
Posted June 1, 2009

Making Our Stock T-Case As Good As Can Be

There's no shame in keeping the factory NP231 T-case that came in your YJ, TJ, or XJ. They're durable, lightweight, easy to work on, relatively compact, and are very well supported by the aftermarket. If the 2.72:1 low range isn't deep enough for you, there are 4.0:1 kits, but for us the factory ratio is perfect. About the only thing the chain-drive NP231s can't do is support twin-stick operation, but there are 2WD Low conversion kits out there.

So, when we heard some bearing noises coming from our 152K-mile NP231 in our '89 Wrangler, rather than shop for a $2,000 replacement T-case, we called up JB Conversions for some components to upgrade our little NP231 to handle the 500hp V-8 and 37-inch tires we eventually plan to run on our YJ. And while we were delving into the T-case, we took the opportunity to install a JB Conversions Super Short Slip-Yoke Eliminator. Check it out as we monsterize our NP231 at home.


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JB Conversions
Sulphur, LA 70664