This is very strange and it has me preplexed. A couple weeks back I noticed that when I've got a passenger in my car, I can feel a vibration through the pedals and seat when the car is under medium and heavy throttle in 5th gear from 70-80mph. If I'm just cruising then everything is fine. It doesn't happen at any other rpm or gear. When I riding by myself, it doesn't do it. The vibration isn't horrendous, but it is noticable to me. I've even changed out rims and the problem is still there.

A few weeks back I replaced my passenger side CV axle (R-axles). The axle looked fine, but when I tested the support bearing, it turned freely but it wasn't terribly smooth. It felt slightly "grindy". I installed it and everything seemed fine. Does it even sound plausible that adding 170+lbs in the passenger seat would be be enough to mess with this bearing? If the bearing really was the culprit, wouldn't I feel and hear problems even without a passenger and at other rpms and speeds?

Have any you tested the support bearing before installing your passenger side CV axle? And if so, did it turn smoothly?

 

Hey Dave,

I'd bet the problem has something more to do with the axle's joints than the bearing. Without the passenger the axel is probably very close to horizontal on H&Rs, but when the passenger steps in, the car sinks down another 1/2 inch and the vibration starts due to the cv joint's new angle it must support. If it were the wheel bearing, the weight of an extra passenger shouldn't affect it much, but the extra passenger could be just enough weight to place an extra angle on the cv's joint.

Hope this helped.

 

Yeah, I'm pretty sure it's not a wheel bearing because the car isn't exhibiting the symptoms. I'm talking about the passenger side CV axle that has the support bearing located in the center of the axle assembly. I got underneath the car and looked at the ball joints, swaybar, exhaust, and all suspension components I could think off. I didn't see anything abnormal. I ended up removing the three bolts that connect the support bearing, rotated the bearing, and then bolted it back up. I did notice that the Nissan tech overtightened the bearing bolts by a significant margin, though I doubt that would cause any problems. All I can think of is there is possibly some strange problem with the axle that only gets affected with additional weight and under mild load. I may shoot Marty at R-axles an email.