Sorento 4WD V6-3.3L (2008)
Control Module: Customer Interest
Drivetrain - Drivetrain Chatter
Model: Sorento [BL]
Group: Driveshaft and Axle (31)
Number: KT2007103001
Date: Tuesday, October 30, 2007
Area: N. America
Subject:
SORENTO DRIVETRAIN CHATTER WITH TOD
(trans/Driveline 019)
Description
There have been several reported conditions of drivetrain chatter due to incorrect tire size. The Torque On Demand (TOD) 4WD system utilizes two
speed sensors for the front and rear propeller shafts. When, due to uneven tire wear or incorrect tire size, the transfer case module receives different
inputs front verses rear, indicating tire slippage, the control module will increase the pulse width (duty cycle %) to the front differential axle through the
transfer case. When this occurs without wheel slippage, chatter may occur and the front differential temperature increases. Failure of the front differential
due to incorrect tire size is not covered under warranty. To prevent premature failure and chatter of the front differential, ensure that the tires are rotated
regularly. To check allowable differences between tires, measure the tire circumference around the outside of the tire; all four tires should be within 10
mm (3/8 inch) of each other. Refer to the tire size designation below for the correct replacement tire size. Always replace tires with the same size, load
and speed ratings; never install tires with a smaller or larger size or lower speed rating. Tires of the same size designation are not always the same
measured outside circumference.
Sorento Tire Replacement
Tire Size Designation:
A tire's sidewall is marked with a tire size designation. You will need this information when selecting replacement tires. The following explains what the
letters and numbers in the tire size designation mean.
Correct Tire Size:
Refer to placecard located on driver's door jamb. Example used in this TSB is P245/70R16 106H.
P = Applicable Vehicle type (tires marked with the "P" are intended for use on passenger
245 = Tire width in millimeters
70 = Aspect ratio (Tire's section height as a percentage of it's width).
R = Tire construction code (Radial).
16 = Rim diameter in inches.
106 = Load index, a numerical code associated with the maximum load the tire can carry.
H = Speed rating symbol. See the speed-rating chart for additional information. Do not install tires lower then this speed-rating.
Tire Speed Rating:
