https://clublexus.com/how-tos is the leading Lexus resource for technical, DIY guides. The serpentine belt is crucial to keeping the engine running smoothly and needs to be replaced over time. For more information, please visit our article at https://www.clublexus.com/how-tos/a/lexus-rx-how-to-replace-serpentine-belt-366262
Traditionally, a serpentine belt goes around all of the pulleys at the front of the motor, thus giving it its name from the serpentine route it takes. However, the Lexus RX is a bit different and has two different belts: one for the power steering and one for the alternator. In the Lexus RX, the power steering belt can break and still leave your car in driving condition, whereas if you break a serpentine belt, you lose the key component your car needs to run: the alternator. The downside is that having two belts makes changing them out more of a headache due to the extra work required. This video covers the process for the Lexus RX 350.
Requiring one to two hours of your time and working in cramped spaces, this moderately difficult job will cost you $30 to $50 dollars in materials, compared to having a professional service the belt for $200 to $300 dollars.
For this job, you’ll need a jack and jack stands, a torque wrench, a twelve millimeter open-ended wrench and socket, a cheater bar, a five millimeter bi-hexagon wrench, a fourteen millimeter open-ended wrench and socket, a Phillips head screwdriver, a wire coat hanger, and a replacement serpentine belt.
Step One – Remove passenger side front wheel
Loosen the lugs on the front passenger side wheel and jack up the vehicle. The lift points are shown here.
Secure the weight of the vehicle on jack stands.
Once secured, finish removing the lug nuts and remove the wheel.
Step Two – Remove serpentine belt panels
Remove the panels from the fender well to gain access to the pulleys. The panel is held in by bolts, but also by the panel directly to the right. Remove the trim pieces until the serpentine belt panel is out of the way.
Step Three – Loosen serpentine belt tensioner
Relax the tensioner by turning the center nut counter-clockwise. Use a long, flat handled socket wrench to get leverage.
Once the tensioner has been relieved, place a 5mm bi-hexagon wrench through the bottom hole to keep it from moving.
Step Four – Replace serpentine belt
Pull the belt from the pulleys and route the new one according to this diagram. Have a stretched-out coat hanger handy to pull the belt up and over some of the upper pulleys if necessary. When finished, twist the tensioner counter-clockwise and remove the 5mm hex wrench.
Don’t forget to re-install the various fender well panels and wheel, and lower the vehicle.