Accessory Drive System - 2.0l Duratec-He Ford Focus ST III

Overview

Note. Early build engines have a 6-rib accessory drive belt, late build engines have a 4-rib accessory drive belt.

The accessory drive system provides power to operate components which power other systems. These could include components such as the generator, power steering pump and A/C compressor. Each of these components is equipped with a pulley which is driven by the accessory drive belt. The accessory drive belt is driven by the engine crankshaft pulley.

The automatic belt tensioner maintains correct belt tension and compensates for component wear and changes in system load. System load changes can be caused by the A/C compressor clutch engaging or disengaging or demand changes on other systems powered by the accessory drive belt. Automatic belt tensioners are calibrated to provide the correct amount of tension to the belt for a given accessory drive system. Unless a spring or damping band within the tensioner assembly breaks or some other mechanical part of the tensioner fails, there is no need to check the tensioner for correct tension.

To maintain correct operation of this system, it is critical that the correct length drive belt is installed. The pulleys must also be correctly aligned and kept clean.

Symptom Chart: Front End Accessory Drive (FEAD)

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. for information regarding Ford-specific diagnostic practices.

Note. Under no circumstances should the accessory drive belt, tensioner or pulleys have any fluids or belt dressing applied to them as damage to the belt material and tensioner damping mechanism may occur.

1. Inspect for signs of drive belt cracking/chunking/wear.
2. Inspect for signs of belt/pulley contamination.
3. Inspect for signs of a incorrect accessory drive belt.
4. Inspect for signs of pulley misalignment or excessive pulley runout.
5. Inspect for signs of loose or mislocated hardware.
6. Inspect for signs of loose accessory drive belt.
7. Inspect for signs of damaged pulleys.
8. Inspect for signs of tensioner arm misalignment.

Symptom Chart(s)

PINPOINT TEST A: ACCESSORY DRIVE BELT NOISE OR FLUTTER

Note. Under no circumstances should the accessory drive belt, tensioner or pulleys have any fluids or belt dressing applied to them as damage to the belt material and tensioner damping mechanism may occur.

1. A1 CHECK THE ACCESSORY DRIVE BELT Check the condition of the accessory drive belt and for correct installation. Repair as necessary. Is the accessory drive belt acceptable? Yes: GO to A2 No: Install a new accessory drive belt.
2. A2 CHECK FOR FLUID CONTAMINATION ON THE ACCESSORY DRIVE BELT Is the accessory drive belt clean and dry? Yes: GO to A3 No: For a drive belt that has been exposed to fluid contamination during vehicle operation, such as leaks from the power steering system, Air Conditioning (A/C) system or cooling system, clean all pulleys with soap and water, rinse with clean water and install a new accessory drive belt. For a drive belt that has been exposed to fluids in a localized area during routine vehicle service, such as replacement of hoses or fluids, the drive belt and pulleys should be washed with soap and water immediately (prior to starting the engine), and rinsed with clean water. A3 CHECK FOR DAMAGED ACCESSORY DRIVE BELT TENSIONER Test the accessory drive belt tensioner. Does the accessory drive belt tensioner function correctly? Yes: GO to A4 No: Install a new accessory drive belt tensioner. A4 CHECK FOR PULLEY MISALIGNMENT OR EXCESSIVE PULLEY RUNOUT Determine the area where the noise comes from. Check each of the pulleys in that area with a straightedge to the crankshaft pulley. Look for accessory pulleys out of position in the fore/aft direction or at an angle to the straightedge. Is the pulley(s) misaligned or have excessive pulley runout? Yes: Inspect the pulley. Repair as necessary. No: GO to A5 A5 CHECK FOR DAMAGED ACCESSORIES Remove the accessory drive belt. Check that each accessory pulley can be rotated by hand in the unloaded condition. Check that each accessory pulley does not feel loose or is binding. Do each of the accessory pulleys rotate smoothly by hand? Yes: GO to A6 No: Inspect the accessories. Install a new accessory if necessary. A6 CHECK THE AIR CONDITIONING (A/C) SYSTEM PRESSURE Test the Air Conditioning (A/C) refrigerant system. Does the Air Conditioning (A/C) system pressure exceed specifications? Yes: Repair as necessary. No: The Front End Accessory Drive (FEAD) system is operating correctly at this time. A short intermittent squeal may have occurred during engine start up and shut down or during very rapid engine acceleration and decelerations, such as Wide Open Throttle (WOT)1-2 and 2-3 shifts or 2-3 and 3-4 back-out shifts on automatic transmissions and Wide Open Throttle (WOT) 1-2 and 2-3 shifts and any combination of rapid downshifting on manual transmissions. These unique short-term momentary events are expected, and are due to the higher system inertias required to meet the electrical and cooling demands on vehicle systems.

Accessory Drive Belt

Note. Under no circumstances should the accessory drive belt, tensioner or pulleys have any fluids or belt dressing applied to them as damage to the belt material and tensioner damping mechanism may occur.

Note. Do not rotate the tensioner by the pulley bolt.

Scheme 1

Scheme 2

1. Check that the belt length indicator on the belt tensioner is in the acceptable belt installation and wear range. If the indicator is in the belt replacement range, either an incorrect belt is installed or the belt is worn beyond the service limit. Install a new belt as necessary. Belt length indicator Acceptable belt installation and wear range Belt replacement range Belt tension relief point NOTE: Incorrect Installation NOTE: Correct Installation
2. With the engine running, check accessory drive belt tracking on all pulleys. If the edge of the accessory drive belt rides beyond the edge of the pulleys, noise and premature wear will occur. Make sure the accessory drive belt rides correctly on the pulley. If an accessory drive belt tracking condition exists, proceed with the following

Accessory Drive Belt Tensioner

1. With the engine off, check routing of the accessory drive belt. Replace if necessary.
2. Using a suitable, commercially available serpentine belt tensioner release tool, release the tension on the belt and detach the accessory drive belt from the tensioner. Carry out the following tests: Using the release tool, move the tensioner from its relaxed position, through its full stroke and back to the relaxed position to make sure there is no stick, grab or bind, and to make sure that there is tension on the tensioner spring. Rotate the tensioner pulley by hand and check for a binding, contaminated or seized condition. Inspect the area surrounding the accessory drive belt tensioner for oil leaks or contamination and repair any leaks.
3. If the accessory drive belt tensioner does not meet the criteria in the previous step, install a new tensioner. If the accessory drive belt tensioner meets the criteria in the previous step, proceed to testing the tensioner dynamically in the next step.
4. Using a suitable, commercially available serpentine belt tensioner release tool, install the accessory drive belt onto the tensioner. With the engine running, observe the accessory drive belt tensioner movement. The accessory drive tensioner should move (respond) when the A/C clutch cycles (if equipped), or when the engine is accelerated rapidly. If the accessory drive belt tensioner movement is excessive without A/C clutch cycling or engine acceleration, inspect the accessory drive belt for uneven depth of grooves. Excessive uneven depth of grooves in the accessory belt can cause excessive accessory drive belt tensioner movement. To diagnose uneven depth of grooves in the accessory drive belt, install a new accessory drive belt. If excessive accessory drive belt tensioner movement still exists, install a new accessory drive belt tensioner.
5. If the tensioner is saturated with oil and grease internally, install a new tensioner.

Air Conditioning (A/C) Compressor Belt

SPECIAL TOOL(S) / GENERAL EQUIPMENT 303-1252/2 Tool, Stretchy Belt Installer 303-1419 Remover, 3.5L / 3.7L Stretchy Belt TKIT-2008SB-FLM

Removal

Installation

Note. Under no circumstances should the accessory drive belt, tensioner or pulleys be lubricated as potential damage to the belt material and tensioner damping mechanism will occur. Do not apply any fluids or belt dressing to the accessory drive belt or pulleys.

Note. Do not rotate the tensioner by the pulley bolt.

Scheme 3

Scheme 4

1. Refer to: «HEALTH AND SAFETY PRECAUTIONS»(/ford/focus-st/iii-2012-2015/remont/oem-general-information/#service-information-introduction-except-electric) .
2. The A/C drive belt procedure must be preformed before removing the Accessory drive belt. Refer to: «Air Conditioning (A/C) Compressor Belt»(/ford/focus-st/iii-2012-2015/remont/accessory-drive-belts/#accessory-drive-system-20l-duratec-he__air-conditioning-ac-compressor-belt) .

1. To install, reverse the removal procedure.

Note. Under no circumstances should the accessory drive belt, tensioner or pulleys be lubricated as potential damage to the belt material and tensioner damping mechanism will occur. Do not apply any fluids or belt dressing to the accessory drive belt or pulleys.

Note. Removal steps in this procedure may contain installation details.

Scheme 5

Scheme 6

1. Refer to: «HEALTH AND SAFETY PRECAUTIONS»(/ford/focus-st/iii-2012-2015/remont/oem-general-information/#service-information-introduction-except-electric) .
2. WARNING: Take extra care when handling the compressed spring.
3. Torque : 25 Nm

1. To install, reverse the removal procedure.

See also:
• SERVICE INFORMATION
• JACKING AND LIFTING - OVERVIEW
• WHEEL AND TIRE
• Pinpoint Test A
• Air Conditioning (A/C) Compressor Belt