Steering/Suspension - Tires Wearing Unevenly
No.: LA204-005Issue: 3
Date: May 22, 2007
SECTION: 204-00
Uneven Tire Wear
AFFECTED VEHICLE RANGE:
LR3 (LA) VIN: 5A000360 to 6A403382
CHANGES MADE FOR ISSUE "3" ARE HIGHLIGHTED WITH GRAY BACKGROUND.
CONDITION SUMMARY:
UNEVEN TIRE WEAR
Situation:
A customer may report a concern of uneven tire wear. The steering alignment geometry of certain vehicles may experience some bushing settlement during early vehicle life. Following initial production geometry setting, this settling may alter the geometry settings outside of normal tolerance, which may in turn increase tire wear.
Revised geometry settings introduced after 6A403382 compensate for this situation.
NOTE:
This situation is not experienced on all vehicles. Toe sensitivity may be attributed to other factors.
CAUTION:
Retailers who sublet alignment to outside shops must provide the information in this bulletin to the alignment facility to ensure proper settings when uneven tire wear symptoms are being addressed. Additionally all vehicles equipped with EAS sent for sublet alignment MUST have been placed in the "tight tolerance" geometry setting mode prior to delivery using IDS.
Action:
Should a customer express a specific concern of uneven tire wear, refer to the Repair Procedure detailed in this bulletin to adjust the vehicle geometry to the "target" settings noted below.
NOTE:
In other situations requiring geometry adjustment, where a specific concern of uneven tire wear is not expressed or diagnosed, the geometry dimensions in the workshop manual should be used. A specific set of "target" geometry data is provided in this bulletin for use in vehicles where the geometry needs to be adjusted to correct an uneven tire wear concern.
PARTS:
No parts required
WARRANTY:
NOTE:
Repair procedures are under constant review, and therefore times are subject to change; those quoted here must be taken as guidance only.
Always refer to DDW to obtain the latest repair time.
NOTE:
The revision to the time in this bulletin is the result of the introduction of the new IDS "tight tolerance" geometry setting mode for suspension adjustments. This simple IDS process replaces and eliminates the requirement to perform a suspension calibration (1.1 hrs) in association with the alignment process. Refer to Technical Bulletin LA204-007 for additional information about the geometry setting mode.
DDW requires the use of causal part numbers.
Labor only claims must show the causal part number with a quantity of zero.
REPAIR PROCEDURE
ALIGN SUSPENSION GEOMETRY
1. If the vehicle has Electronic Air Suspension (EAS), refer to Technical Bulletin LA204-007, connect IDS to the vehicle and place the Electronic Air Suspension (EAS), into "tight tolerance" geometry setting mode.
NOTE:
A small number of coil sprung vehicles were imported into North America at the very start of LR3 importation. Step 2 is included in the event that such a vehicle requires suspension alignment.
2. If the vehicle has coil spring suspension, perform the following steps to ensure that the equivalent of a full tank of gasoline weight is present in the vehicle when the alignment process is performed:
NOTE:
LR3 fuel tank capacity is 22.7 US gallons (86.3 liters). A full LR3 fuel tank weighs approximately 152 lbs (69 kg).
^ Accurately determine the volume of fuel in the tank.
^ If the tank is not full, calculate the weight of the fuel in the tank using one of the following formulas:
^ Multiply the number of US gallons of fuel by 6.7 to equal total pounds of fuel.
^ Multiply the number of liters of fuel by 0.8 to equal total kg of fuel.
NOTE:
Any weight equivalent placed into the load space area must be evenly distributed at the front and the right hand side of the load space.
^ Calculate the weight equivalent that must be added to the load space area by subtracting the total amount of fuel currently in the tank from the LR3 fuel tank capacity of 152 lbs. (69 kg).
NOTE:
Vehicles that have any of the front or rear, upper or lower control arm bushings changed must complete a ten mile road test before having the geometry checked and adjusted if necessary. The road test will allow the suspension to settle.
NOTE:
GTR lookup sequence is as follows:
GTR Home> NAS > Service Information/ LA - LR3 > Workshop Manuals> Bookmark "Chassis/Suspension/204-00: Suspension System - General Information" Link "Four-Wheel Alignment (57.65.04)"
CAUTION:
GTR identifies an alignment specification range.
The exact "TARGET SPECIFICATIONS" in the table shown should be used on vehicles that have experienced uneven tire wear.
When setting suspension geometry after front or rear/upper or lower control arm bushing replacement, the rear toe should be set to the TARGET SPECIFICATION in the table.
3. Refer to GTR section 204-00 Four-Wheel Alignment operation 57.65.04 and adjust the front and rear wheel alignment to the TARGET specification figures noted in the table.
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