Drive Belts, Accessory

NOTE: Drive belts (8620) have automatic drive belt tensioners (6B209) and do not require adjustment.

Vehicles are equipped with:

• V-ribbed serpentine accessory drive belts .
• Automatic drive belt tensioners .

The belt type is selected for each engine based upon engine performance requirements. Replacement drive belts should be of the same type as originally installed.

The 3.8L and 5.0L engine drive belt condition should be checked at:

• 96,000 km (60,000 miles).
• Then every 24,140 km (15,000 miles) thereafter.

Under severe operating conditions (high temperatures, low humidity), drive belt rib cracking can occur at less than 80,000 kilometers (50,000 miles). Drive belt rib cracking (cracks across ribs):

• Has no detrimental effect on drive belt performance.
• However, cracks running with backing are not acceptable.

The drive belt is still perfectly functional until rib "chunking" occurs. Drive belt "chunking" is where the rubber material actually chunks out between the cracks. The drive belt should be replaced if chunking occurs.

"V" Ribbed Drive Belt With Cracks Across Backing






"V" Ribbed Drive Belt With Chunks of Rib Missing

Drive belt "chirp" is a noise that occurs due to pulley misalignment or excessive pulley runout. It can be a result of a damaged pulley or an improperly replaced pulley that was not properly aligned.

Drive belt squeal is an intermittent noise that occurs when the drive belt slips on a pulley during certain conditions such as: engine start up, rapid engine accelerations, or A/C compressor clutch engagement.

Drive belt squeal can occur under the following conditions:

• If the A/C discharge pressure goes above 2895 kPa (420 psi). This can occur if:
  1. The A/C system is overcharged.
  2. The A/C condenser airflow is blocked.
  3. The radiator electric motor (8K621) is not operating with the A/C on.
• If A/C off equalized pressure (the common discharge and suction pressure that occurs after several minutes) exceeds 965 kPa (140 psi), which is a rare occurrence at high ambient temperatures with a hot engine, turn A/C OFF for a few seconds and then back ON after radiator electric motor and fan blade (8600) begin to cool A/C condenser core (19712) .
• If fluids get on the drive belt . This would include power steering fluid, engine coolant, engine oil, air conditioning system lubricant; clean the drive belt with soap and water and thoroughly rinse with clean water. The drive belt does not have to be replaced if no apparent damage has occurred.
• If the drive belt is too long, it will allow the drive belt tensioner to go all the way to the tensioner travel stop. If the drive belt tensioner is resting on the stop, replace the drive belt .

The drive belt tensioner should rotate freely without binding.

All of the accessories should be rotatable by hand in the unloaded condition. If any are not, the accessory should be replaced.