Tech Feature: Wheel Bearing Service on Hybrid Vehicles – UnderhoodService

Tech Feature: Wheel Bearing Service on Hybrid Vehicles

Most hybrid vehicles on the market today share wheel bearing components with their non-hybrid counterparts. There is no need to turn away these vehicles for wheel bearing replacement. As these vehicles increase in age, failures of the wheel bearings are inevitable. The main trend for some makes of hybrids, such as Toyota, is a shift to wheel bearing hub units from cartridge-type bearings.

  When servicing these vehicles, it is critical that the hybrid or regenerative brake systems be disabled. It should be a common practice to remove the keys from the vehicle and place them in an area that is far enough away from the vehicle. Some hybrids systems will sense if the key is near. As the driver approaches the vehicle, some vehicles will not only unlock the doors, but activate systems like brakes and drivetrain.
It is critical for the technician to check the service information and deactivate these systems before removing calipers and wheel speed sensors.
 
FORD:
2005-current Escape Hybrid/Mercury Mariner
Front: Hub Unit with integrated wheel speed sensor
Rear: Hub Unit with integrated wheel speed sensor
Tips: When servicing the wheel speed sensors on a 2001-2005 Escape or 2005 Mariner and Escape Hybrid, care must be taken during removal to prevent damage to the wiring harness of the wheel speed sensors. The wheel speed sensor wire has a body plug attached to it. This plug can be damaged if not removed correctly, such as removal for pinpoint testing. If the body plug is damaged, sensor replacement may be necessary even though the sensor is functional in all other respects. When removing the body plug, rotate the plug into a position which allows the use of a small screwdriver to release the tabs on the underside of the body plug. These two tabs are at right angles (directly above and below) to the sensor wire.

GM
2008-current Chevrolet Malibu Hybrid
Front: Hub Unit with integrated wheel speed sensor
Rear: Hub Unit with integrated wheel speed sensor

2007-2009 Chevrolet Tahoe Hybrid (2WD)
Front: Hub Unit with integrated wheel speed sensor
Rear: Housed in the rear axle

Tips: No differences from the non-hybrid models. But, when servicing these vehicles equipped with TPMS make sure you have the correct tools to “re-learn” the sensors positions if the tires are rotated.
 
Honda 1999-2006 Insight
Front: Bolt-in cartridge style
Rear: Hub unit

2006-2009 Accord and Civic Hybrids

Front: Cartridge-Type with Encoded Tone Ring
Rear: Hub Unit

Tips: The front knuckle should be removed for bearing replacement. Install the wheel bearing with the wheel sensor magnetic encoder toward the inside of the knuckle. The side with the ABS ring can be identified either by placing a lightweight metallic object (such as a paper clip) to the magnetic side or by a close visual inspection. The close visual inspection will reveal the ABS impulse ring windows, which can be seen through the seal surface. Remove any oil, grease, dust, metal debris and other foreign material from the encoder surface. Keep all magnetic tools away from the encoder surface. Be careful not to damage the encoder surface when you insert the wheel bearing.

Toyota Prius 2001-2003

Front: Cartridge type
Rear: Hub Unit with tone ring on the rear of the unit. Magnetic wheel speed sensor mounts behind the unit.
Tips: Do not allow any foreign matter sticking to the sensor rotor. Pull out the ABS speed sensor straight, in order not to damage the sensor rotor. If damage has occurred to the rear sensor rotor on the hub unit, replace the hub. Do not scratch the contacting surface of the axle hub or cartridge bearing and speed sensor.
 
Toyota Prius 2004 and up
Front: Hub Unit with integrated wheel speed sensor
Rear: Hub Unit with integrated wheel speed sensor
Tips: Do not twist the wires. Make sure the sensor’s wires in routed like the original.
 
Lexus
2006-2008 RX400h
Front: Cartridge-Type Bearing
Rear: Cartridge-Type Bearing

2007-2009 GS450h
Front: Hub Unit with integrated wheel speed sensor
Rear: Hub Unit with integrated wheel speed sensor
Tips: When the brake caliper is removed from the brake disc, do not start the hybrid system. If the hybrid system is started, the brake fluid pressure may increase.

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