Jeep Tech Tip: Dirt and Debris Accumulation at Rear Main Seal

Jeep Tech Tip: Dirt and Debris Accumulation at Rear Main Seal

The customer may experience engine seepage from the area of the rear main bearing seal. Closer inspection may reveal that the cause of the engine oil seepage past the rear main bearing seal is due to the accumulation of dirt and debris around the outside of the rear main seal. This condition may occur more frequently of the vehicle is used in off-road conditions.

Models:
• 1997-2005 (TJ) Wrangler

Note: This bulletin applies to vehicles equipped with a 4.0L engine (sales code ERH) and a manual transmission (sales code DDQ, DDD or DEH) that were built prior to September 2, 2004 (MDH 0902XX)

Symptom/Condition:
The customer may experience engine seepage from the area of the rear main bearing seal. Closer inspection may reveal that the cause of the engine oil seepage past the rear main bearing seal is due to the accumulation of dirt and debris around the outside of the rear main seal. This condition may occur more frequently of the vehicle is used in off-road conditions.

A spacer plate is used to mate the transmission bellhousing to the back of the engine. The spacer plate has a slot machined into it at the 12 o’clock position. A small opening may occur as a result of the spacer slot when the spacer is mated between the engine and transmission bellhousing. The narrow spacer opening at the top of the transmission bellhousing may allow small size debris to enter the bellhousing and accumulate around the outside of the rear main engine seal. If debris accumulation becomes significant, damage to the rear main seal may occur.

Diagnosis:
If a vehicle is in for service, perform the Repair Procedure if the repair has not previously been performed.

If engine oil seepage from the engine rear main oil seal is present, then diagnosis and repair not addressed by this bulletin may be required.

Repair Procedure:
1. With the ignition switch in the off position, raise the vehicle hood and make sure the engine and exhaust manifold are not hot to the touch.

2. Locate the narrow opening created by the spacer plate. The spacer opening can be viewed when looking towards the rear of the engine and top of the transmission bellhousing from the driver’s side of the engine.

3. Thoroughly clean the immediate area around the spacer opening with throttle body cleaner, p/n 04897156AA. Allow cleaner to dry.

4. Apply a sufficient amount of RTV over the spacer opening. Verify that the spacer opening is completely sealed off by the RTV.

5. Lower and secure vehicle hood.

Courtesy of Mitchell 1.

For more information on Mitchell 1 products and services, automotive professionals can log onto the company’s website at www.mitchell1.com.

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