Overview
The Omix-ADA NP231 oil tube O-ring, part number 18680.36, is a replacement O-ring for the oil tube on the NP231 transfer case. It fits Jeep Cherokee (XJ), Grand Cherokee (ZJ), Liberty (KJ) and Wrangler (LJ, TJ and YJ) vehicles.
It is made for the NP231 transfer case, and the fitment section below breaks down the vehicles and trims.
Key features
- Fits the NP231 transfer case
- Factory-style replacement O-ring from Omix-ADA
- Listed Jeep applications span 1984 to 2006
- Trims for each model are named below
Oil tube seal care
The oil tube carries lubricant through the transfer case circuit, and the O-ring at its joint keeps that path sealed. When the O-ring hardens or cracks, fluid can seep out at the joint and the level drops over time, often without an obvious puddle under the vehicle.
Replacing an O-ring is simple in principle but depends on access. Remove the tube carefully, clean the bore and tube end, and lightly coat the new O-ring with transfer case fluid before seating it. Avoid twisting the O-ring during installation, since that can tear it and start a new leak.
When the case is already open, consider replacing other aged seals at the same time, since rubber parts often wear together. Check the level after the first drive.
- Seepage at the tube joint
- Dropping fluid level between services
- Hardened or flattened O-ring on removal
Specifications
| Brand | Omix-ADA |
|---|---|
| Part number | 18680.36 |
| UPC | 804314162337 |
| Type | Oil tube O-ring |
| Transfer case | NP231 |
Vehicle fitment
It fits:
- 1984 to 2001 Jeep Cherokee (XJ), Base, Briarwood, Chief, Classic, Country, Laredo, Limited, Pioneer, SE and Sport trims
- 1993 to 1998 Jeep Grand Cherokee (ZJ), 5.9 Limited, Base, Laredo, Limited, Orvis, SE and TSi trims
- 2002 to 2004 Jeep Liberty (KJ), Limited, Renegade and Sport trims
- 2004 to 2006 Jeep Wrangler (LJ), Unlimited and Unlimited Rubicon trims
- 1997 to 2006 Jeep Wrangler (TJ), 65th Anniversary Edition, Rubicon, SE, Sahara, Sport and X trims
- 1987 to 1995 Jeep Wrangler (YJ), Base, Islander, Laredo, Renegade, Rio Grande, S, SE, Sahara and Sport trims
The Cherokee XJ list stops at 2001 and the Wrangler TJ list at 2006. Wrangler JK models are not on the list. Confirm your vehicle’s year, model and trim before ordering.
What’s included
The O-ring only. No other seals or gaskets are mentioned.
