Drivetrain› 4x4 Driveline Components

USA Standard Gear

NP231J Transfer Case Bearing and Seal Overhaul Kit

$129.89

SKU: ZTBK231J

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Free Shipping over $200
$100 Minimum Order
Non-Returnable Item
INSTALL DIFFICULTY
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Moderate — 2–4 hours

Overview

The USA Standard Gear ZTBK231J is a transfer case bearing and seal overhaul kit designed for the NP231J transfer case with a narrow input. This kit includes all necessary bearings, seals, gaskets, and snap rings to rebuild the transfer case.
Show original supplier description
The USA Standard Gear ZTBK231J Transfer Case Bearing and Seal Overhaul Kit provides everything needed to refresh the internal components of your NP231J transfer case. This kit is specifically designed for NP231J transfer cases with a narrow input, featuring an input bearing width of 16 mm (0.63 Inch) and a rear mainshaft bearing OD of 72 mm (2.83 Inch). The kit is made in the USA and includes all essential wear items such as bearings, seals, gaskets, and snap rings. It is ideal for both full rebuilds on high-mileage units and preventative maintenance, supporting off-road usage and keeping your transfer case running strong with precision-engineered components that meet or exceed OEM standards. Installation of this kit involves complete transfer case disassembly, and professional installation is recommended to ensure accurate shim setup and proper seal fitment. The kit is compatible with 1995-2001 Jeep Cherokee models, 1995 Jeep Grand Cherokee models, and 1995-2006 Jeep Wrangler models equipped with the NP231J transfer case with a narrow input, aluminum case, and chain drive.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandUSA Standard Gear
Part NumberZTBK231J
CategoryDrivetrain
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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