Jeep Cherokee Forum

Jeep Grand Cherokee 1993-2004: General 4WD Information and Maintenance Schedule

The transfer case is used to transfer power to the front wheels during situations where maximum traction is needed. It is used in combination with the front axles, differentials, and driveshafts to transfer the engines power with no adverse effects to the vehicles drivability.

By Weston Chadwick - October 2, 2015
Contributors: CDX Automotive, 89Laredo, JeepCoMJ, cruiser54, Kyle, razor02097, 9294Forrest

This article applies to the Jeep Grand Cherokee WJ/ZJ (1993-2004).

Transfer cases are used in four-wheel drive and all-wheel drive vehicles to split power to the front as well as rear drive axles. The transfer case is bolted to the rear of the transmission. The output shaft of the transmission is splined to the input shaft of the transfer case. Power moves from the input shaft to the rear output shaft. Power is also sent through the front output shaft when four-wheel drive is selected. Inside the transfer case is a large chain that connects and moves the front output shaft. When you move the mode selection lever a shift or "mode," fork moves the synchronizer sleeve and locks it to the input shaft chain sprocket.

The Grand Cherokee uses several different styles of transfer case depending on the year, trim level, and engine size. Each transfer case has unique characteristics and functions. Correctly identifying your Grand Cherokee's transfer case will allow you to determine what maintenance it needs and the problems other owners have encountered.

Component Breakdown

NP 242 Transfer Case

This transfer case is used on inline 6-cylinder ZJ's and WJ's. It's also known as "Select-Trac." The 1993 and 1994 ZJ's with a V8 engine had an option for this transfer case. The 242 has available full-time 4WD. This mode can be used in any driving condition. The 242 has its own differential, allowing for different speeds at the front and rear axles, reducing drive line bind.

Figure 1. The 242 transfer case.

NP 249 Transfer Case

This transfer case was used on all V8 ZJ's and WJ's. It was an option on 6-cylinder models. It is also known as Quadra-Trac.

Figure 2. The 249 and 231 transfer cases.

NP 231 Transfer Case

This transfer case was used on various heavy duty ZJ and WJ V8 Jeeps. Also known as Command-Trac. In 1993 and 1994, this transfer case was an option on inline 6-cylinder engines with SE or Laredo trim.

Figure 3. The 231 transfer case.

NV 247 Quadra-Trac II

In 2002, this transfer case was introduced as an option for V8 Jeeps. Also known as Quadra-Drive. This is an all-wheel drive system similar to systems found on Audi and Subaru. In 2004 on WJ's with Laredo trim another version of the Quadra-Trac became available known as Quadra-Trac I.

Figure 4. A diesel Jeep with Quadra-Trac II.

Scheduled Maintenance

Here is a breakdown of the transfer case lubrication service on the Grand Cherokee WJ. You can identify the type of transfer case your Jeep has by a red circular tag at the rear (as seen in Figure 1).

Your owner's manual can be downloaded from Jeep's site.

  1. NV242: 2.85 to 3 pints of Mopar ATF+4 type 9602. Inspect/change the fluid at 30,000 miles or 24 months. Shorten the duration to 24,000 miles if your driving is more extreme.
  2. NV147: 3.4 pints of Mopar Transfer Case Lubricant (part number 05016796AB). Inspect or change the fluid at 60,000 miles.
  3. NV247: 3.4 pints of Mopar Transfer Case Lubricant (part number 05016796AB). Inspect or change the fluid at 30,000 miles or 24 months. Shorten the duration to 24,000 miles if your driving is more extreme.

Common Questions

What are the differences between full-time and part-time four-wheel drive?

Full-time four-wheel drive acts like an open differential. It can power both the front and rear wheels, but allow them to turn at different speeds. Part-time four-wheel drive locks your axles together. With it engaged on the street while turning, you may notice wheel hop and drive line bind. Your tires may also wear unusually.

How can I correctly shift into and out of four wheel drive?

You may need to move the vehicle forward or backward slightly for the transfer case to fully engage, especially in cold weather.

When shifting "on the fly" between 2WD, 4WD part-time or 4WD full-time, it may be necessary to briefly lift off the throttle once or twice.

Never attempt to engage 4WD Low going faster than five miles per hour. You cannot shift shift into 4WD Low "on the fly." The vehicle must be moving slowly (less than five miles per hour and the transmission shifted to neutral).

Why is my Jeep popping and shaking during turns?

You may have the wrong 4WD mode engaged. The popping as well as shaking is a result of both front and rear axles locking together. This causes the drive line to bind because the front and rear wheels will be turning at different speeds during a turn. This condition may also be present when there's a problem with your viscous coupling.

Common Issues

Only Part-Time 4WD Light Illuminates

The 231 transfer case will only illuminate the part-time light.

"Service 4WD Switch" Light Illuminates

This is a switch located above the transfer case. It tells the VIC whether the 4WD system is in high or low. This switch will not affect the system's operation.

Technical Service Bulletins (TSB)

  • 11-10-1994: #37855 New front output seal and oil slinger for the transfer case
  • 01-01-1995: #39050 New front propeller shaft for vehicles equppied with a Quadra-Trac transfer case
  • 01-01-2003: #10003243 NV247 Transfer Case - GPOP - Issue review system
  • 01-01-2013: #10003244 Snap ring access plug, NV247 transfer case - GPOP - issue review system
  • 6-04-1999: #606170 Concerns with shudder noise present in transfer case
  • 12-11-1998: #603157 A shudder and low pitched grunting noise may be present in the transfer case

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