Preliminary Inspection
Replacement tires must follow the recommended:
The use of any other tire/wheel size, load range or type can seriously affect:
New wheels need to be installed when the vehicle wheels:
It is mandatory to use only the tire sizes recommended on the tire label located on the driver door or door pillar attached to the vehicle. Larger or smaller tires can damage the vehicle, affect durability and require changing the speedometer calibration. Make sure wheel size and offsets match those recommended for the tire in use.
Inspect the tires for signs of uneven wear. Refer to the following descriptions to identify the type of wear and GO to Symptom Chart — Tire Wear for the appropriate repair action to be carried out.
Check the tires for:
Check the valve stems for:
Install a new valve stem when damage is found or anytime a new tire or wheel is installed.
Tread wear indicators are molded into the bottom of the tread grooves. Install a new tire when the indicator bands become less than measurement 2/32 inch.
Tire Wear
Tire wear is commonly defined as a loss of tread depth. Tire tread wear occurs due to friction with the contact surface (road/pavement). The tread should wear down uniformly all the way around the circumference of the tire and all the way across the tread face. When this does not occur, the tire may have abnormal/incorrect wear.
Normal Tire Wear
Normal tire wear is identified as even wear around and across the tread. Because there are many factors (driving style, road surfaces, type of vehicle, type of tire) that can affect tire wear, there is no absolute mileage expectation for a normal wear condition. A tire is considered worn-out when the tread has worn to the level of the tread-wear indicators.
Abnormal/Incorrect Tire Wear
Abnormal/incorrect tire wear is identified as tire wear that is not even around or across the tread and that creates performance-related issues.
Abnormal/incorrect wear can be caused by numerous factors, some of which include driving style (aggressive, passive), climate (hot, cold), road conditions, vehicle loading and maintenance (correct tire pressure, rotation intervals and balance). It is important to determine the root cause of wear on a vehicle before carrying out repair. Tires exhibiting abnormal/incorrect tire wear may still be serviceable provided that the minimum tread depth is greater than and the tire is not causing a vehicle performance (noise/vibration) concern.
Inner Edge/Shoulder Wear
Inner edge (or shoulder) wear occurs on the inside edge of the tire and is usually caused by excessive toe out and/or excessive negative camber. If the tread depth of the outer shoulder is at least 50% greater than the tread depth of the inner shoulder, the tire is experiencing inner edge/shoulder wear. To determine whether tires have this type of wear, visually inspect the tires. In some instances, it may be necessary to measure the tread depth of each rib and compare it to that of the shoulder.
NOTE: Right Front tire shown, others similar.
Outer Edge/Shoulder Wear
Outer edge (or shoulder) wear occurs on the outside edge of the tire and is usually caused by excessive toe in and/or excessive positive camber. If the tread depth of the inner shoulder is at least 50% greater than the tread depth of the outer shoulder, the tire is experiencing outer edge/shoulder wear. To determine whether tires have this type of wear, visually inspect the tires. In some instances, it may be necessary to measure the tread depth of each rib and compare it to that of the shoulder.
NOTE: Right Front tire shown, others similar.
Heel/Toe Wear
Heel/toe wear (also known as feathering) occurs along the outside or inside edge/shoulder of the tire. To determine whether tires have this type of wear, visually inspect the tires in both the inside and outside shoulder ribs. In some instances, it may be necessary to measure the difference in tread depth of leading versus trailing edge of each lug in the inside and outside shoulder rib.
Diagonal Wear
Diagonal wear occurs diagonally across the tread area and around the circumference of the tire. To determine whether tires have this type of wear, visually inspect the tires to determine if the wear pattern runs diagonally across the tread and around the circumference of the tire. In some instances, the difference in tread depth along the diagonal wear pattern may need to be measured.
Symptom Chart(s)
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
WARNING: Vehicle may have multiple drive wheels. Do not use engine to power the driveline unless all drive wheels are elevated off the ground. Drive wheels in contact with ground could cause unexpected vehicle movement. Failure to follow this instruction may result in serious personal injury.
Symptom Chart: Tire Wear
Condition | Possible Sources | Actions |
---|---|---|
Inner edge/shoulder wear |
|
GO to Pinpoint Test A |
Outer edge/shoulder wear |
|
GO to Pinpoint Test B |
Heel/toe wear |
|
ROTATE the wheel and tire assemblies. CHECK the alignment, ADJUST as necessary. |
Diagonal wear |
|
GO to Pinpoint Test C |
Loose, worn or damaged suspension components | REFER to: Suspension System (204-00 Suspension System - General Information) . |
Symptom Chart: NVH
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, for the next likely system and continue diagnosis.
Condition | Possible Sources | Actions |
---|---|---|
Wobble or shimmy | Bent wheel | INSTALL a new wheel as necessary. |
Damaged tire | INSTALL a new tire as necessary. | |
Loose wheel nuts | TIGHTEN to specification. | |
High-speed shake | Tires/wheels | REFER to Radial Runout Measurement - Loaded Hunter Road Force® Method or Radial Runout Measurement - Dial Indicator Method. |
Vehicle vibration | Tires/wheels | REFER to Radial Runout Measurement - Loaded Hunter Road Force® Method or Radial Runout Measurement - Dial Indicator Method. |
Pinpoint Tests
Diagnostic Overview
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Possible Sources
|
||||
A1 MEASURE THE TREAD DEPTH | ||||
Is the tread depth greater than 1.588 mm (0.0625 in) ?
|
Diagnostic Overview
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Possible Sources
|
||||
B1 MEASURE THE TREAD DEPTH | ||||
Is the tread depth greater than 1.588 mm (0.0625 in) ?
|
Diagnostic Overview
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Possible Sources
|
||||
C1 MEASURE THE TREAD DEPTH | ||||
Is the tread depth greater than 1.588 mm (0.0625 in) ?
|
Component Test- Radial Runout
Radial runout is the egg-shaped deviation from a perfect circle and is measured perpendicular to the circumference. On a wheel and tire assembly, this means measuring the center tire tread rib. The center rib is indicative of the condition of the tire as a whole. Total runout is the difference between the maximum-to-minimum gauge reading. The high spot is the location of maximum runout.
Item | Description |
---|---|
1 | High spot |
2 | Low spot |
Radial Runout Measurement - Loaded Hunter Road Force® Method
NOTE: Diagnosis of tire/wheel vibration should not be performed on tires with less than 198 mi (320 km). Some initial tire/wheel vibration issues (such as flat spotting) may correct themselves after the tires have been in service for 198 mi (320 km). This procedure is intended to assist with the diagnosis of wheel and tire assembly runout and/or force variation issues. The Hunter Road Force® 9700 Series Wheel Balancer measures the wheel and tire assembly's loaded runout and the tire's radial spring rate. The balancer then converts the runout into pounds of force (termed as Road Force). Measuring loaded runout (Road Force) is more effective than measuring unloaded runout using a dial indicator.
NOTE: Use only a digital tire pressure gauge any time tire pressures are measured to be sure that accurate values are obtained.
Make sure that the tire pressures are set to the correct pressure as indicated on the VC label.NOTICE: Make sure that the correct wheel balancer adapters are used when mounting the assembly to the wheel balancer or damage to the wheel may occur.
NOTE: Make sure that the wheel and tire assembly is clean and free of foreign material prior to installation on the balancer.
NOTE: The wheel balancer inflation station must be turned OFF for tires with inflation pressures of 60.0 psi ( 414 kPa) or above.
Mount the wheel and tire assembly on a suitable wheel balancer using the correct wheel balancer adapters as shown.Item | Description |
---|---|
1 | Wheel balancer |
2 | Cone |
3 | Wheel and tire assembly |
4 | Finger plate |
5 | Balancer wing nut |
Radial Runout Measurement - Dial Indicator Method
NOTE: Diagnosis of tire/wheel vibration should not be performed on tires with less than 320 km (200 mi). Some initial tire/wheel vibration issues (such as flat spotting) will correct themselves after the tires have been in service for 320 km (200 mi).
NOTE: Loaded run-out measurements are the preferred method for verifying tire serviceability. While a dial indicator can be used to optimize the position of the tire on the wheel, the unloaded run-out measurement cannot accurately determine if the tire should be removed from service.
NOTE: The following procedures should be used if normal diagnostics leads to a potential runout issue.
NOTE: Some vehicles may exhibit a wheel and tire vibration caused by excessive runout. Radial runout measurements can be taken using a dial indicator and should be measured with the wheel and tire assembly mounted on a suitable wheel balancer. The dial indicator should be mounted securely to eliminate gauge movement when measuring runout.
NOTE: Use only a digital tire pressure gauge any time tire pressures are measured to be sure that accurate values are obtained.
NOTICE: Make sure that the correct wheel balancer adapters are used when mounting the assembly to the wheel balancer or damage to the wheel may occur.
NOTE: Make sure that the wheel and tire assembly is clean and free of foreign material prior to installation on the balancer.
NOTE: The wheel balancer inflation station must be turned OFF for tires with inflation pressures of 60.0 psi ( 414 kPa) or above.
Mount the wheel and tire assembly on a suitable wheel balancer using the correct wheel balancer adapters as shown.Item | Description |
---|---|
1 | Wheel balancer |
2 | Cone |
3 | Wheel and tire assembly |
4 | Finger plate |
5 | Balancer wing nut |
NOTE: Masking tape can be applied on the center tread rib to allow for a smoother measuring surface. Some fluctuation of the gauge reading is expected. Observe the overall sweep of the gauge from the highest to the lowest spot on the tire.
Position a suitable dial indicator and stand with the dial indicator on the center tread rib.WARNING: Airbags can kill or injure a child in a child restraint. Never place a rear-facing child restraint in front of an active airbag. If you must use a forward-facing child restraint in the front seat, move the seat upon which the child restraint is installed all the way back.