I have a 2009 Prius with 240k on the odometer. It consumes zero oil and I'd like to hang on to it for another 50k miles, meaning that I'm willing to spend time and money to fix it. With only 40k miles on its Michelins I get a low amplitude tremor in the steering wheel at 60+ mph accompanied by an audible suspension-related rumble from the front end. The tremor and rumble could be tire wear but I think the problem is more complicated because these tires look and feel good when I touch them. No visible cupping or tread wear. I've been getting the full life of tires on this car. If I touch the gas at 60+mph (so as to put a bit of engine torque on the front drive train) the tremor and rumble stop immediately and return when I back off the gas. Alternatively, if I rotate the steering wheel +/- 5 degrees either side of its twelve o'clock neutral position at high speed, the tremor and noise stop. They return when the steering wheel returns to its happy position. ***Is this indicative of CV joint wear?*** In summary, the noise and vibration disappear with slight rotation of the steering wheel or application of torque. If I drive in tight circles at slow speed in a big parking lot with the IC engine off (just electric power) there is no sound coming from the front suspension. I've always believed that the first indicator of worn CV joints is that they make noise in tight turns, but I get none. I've had more than a dozen wheel bearings go bad on various Gen 2/Gen 3 Priuses over the past 18 years and know the familiar buzzing/rumbling sound and feel that failing bearings make. This problem is not related to wheel bearings. And the front struts and sway bar bushings are relative young, maybe new 50k ago. Thanks for any feedback you could offer on this.
I think you're noticing the roughness of a 4-cylinder engine that is being allowed to seek the absolute minimum RPM in steady-speed driving. Probably indicates a healthy hybrid battery too. I've never had a CV joint fail that did not first reveal itself at high steering deflection angles. I mean maybe you're feeling the differential seek back and forth through the driveline lash? Possible at that level of wear I suppose.
I suggest jacking the front up and making sure that all of the suspension bolts are tight and that there is no other slop present. If nothing turns up, examine the back the same way. Other than that, other areas that might cause this would be tire imbalance (threw a weight or shop that recently serviced the wheels balanced them wrong), the engine mounts, and the power steering.
Swap the tires front to rear and recheck. Check for loose ball joints or tie rods - rare on a Toyota but check anyway. Outer CV joint problems (almost) always present as a sharp rhythmic snapping or popping noise in tight turns with throttle applied (parking lot maneuvers). Could be left or right turns, forward or reverse direction. Inner CV joint problems often show as vibration when on throttle at highway speeds. Light throttle cruise, coast or decel makes it go away. Can't say as I have ever seen one act up on decel - but won't say it's impossible. Wheel bearings can have different intensities of noise - vibration when they go bad. Often they can be quiet if you turn the steering wheel slightly to one side - but stay noisy if you turn slightly to the other. Posted via the PriusChat mobile app.
