Tech Tip: Humming Sound From Front of Volkswagen Vehicles During Cornering – UnderhoodService

Tech Tip: Humming Sound From Front of Volkswagen Vehicles During Cornering

A customer states that a humming sound is coming from the front of the vehicle on turns in vehicles equipped with a 02J or 0A4 manual five-speed transmission. The hum may be more noticeable during slow speed turning maneuvers with the steering wheel almost to full travel. The hum diminishes when the steering wheel is straight. This hum may be generated by the differential spider gear contacting the one-piece thrust washer when it is under load.

A customer states that a humming sound is coming from the front of the vehicle on turns in vehicles equipped with a 02J or 0A4 manual five-speed transmission. The hum may be more noticeable during slow speed turning maneuvers with the steering wheel almost to full travel. The hum diminishes when the steering wheel is straight.

This hum may be generated by the differential spider gear contacting the one-piece thrust washer when it is under load.

Models affected:
1998-2006 New Beetle, 1999-2005 Jetta, 2000-’06 Golf, 2003-’06 New Beetle Convertible and 2005-’06 New Jetta.

Service Procedure:
0A4 Manual 5-Speed Transmission, Draining and Refilling:

If the vehicle exhibits this condition, drain and refill the transmission as follows.

Note: It is no longer possible to accurately check the transmission oil level in the same manner as previous model years.

The engine/transmission angle has changed and, therefore, the lower edge of the oil fill hole is located below the new oil level.

To properly check the oil level, the transmission must be drained completely and refilled.

Tip: The transmission housing must be cleaned and dried before servicing.

The shift fork pins must be removed in order to drain the transmission.

Selector Shaft, Securing:
• Remove the air cleaner housing.

• Remove the sound insulation.

• Clean and dry the transmission.

• Secure the selector shaft so that the position of the shift fork pins cannot move: 

• Press the selector shaft down.

• While the selector shaft is held in the down position, turn the bracket upward (clockwise) and press inward until the bracket latches in the selector shaft.

Tip: Use a clean 3.0L container with graduated markings to catch the draining oil.

Transmission, Draining:

• Remove the transmission drain plug and bearing pin; allow the transmission to drain completely.

• Install the bearing pin using a new grommet.

• Install the drain plug.

• Turn the bracket back to its original position so the selector shaft can move freely.

Transmission, Filling:
• Add new transmission oil (P/N G 055 726 A2) to the oil already in the catch container until the total volume is 1.9L (2 qt.).

• Remove the backup light switch.

• Connect a rubber hose approximately 24” (600 mm) long with a 2/8” (10 mm) diameter to a funnel.

• Insert the hose into the hole of the backup light switch and fill the transmission.

• Install the backup light switch.

• Check the operation of the shifter.

• Install the air filter housing

• Install the sound insulation.

For 02J Manual 5-Speed Transmission, Draining and Refilling, see Repair Manual Group 34, Manual Transmission Controls, Housing.

Courtesy of Mitchell 1.

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