Drive Train Noise

[tgrumaj]

Well, here's a new one. When driving I am now hearing a whining noise especially when decelerating around 30-40 MPH. It's more of a "WWRRRRRR" noise. Since it will rise and fall in pitch with the car speed my first thought was the tires. I have Nokian WRs and they have been on since November with no problem. I checked tire pressure and that's fine (I run at the recommended pressure of 36 front and 41 rear). I have just noticed this over the past week. Before that everything was quiet...virtually no tire noise. I wonder if this could be a transmission or bevel gear issue? Any thoughts?

There is no change in performance that I can tell, just the increased noise while driving and the "WHRRRRRRRR"noise increasing as I decelerate. At very low speed it isn't noticable at all.

[Ken from RI]

I've got the same year and model. Have the same "noise" that your describing. After looking under the car, touching, feeling and pulling on the drive shaft and talking to other XC drivers in the area. what we think the sound is is the out put pinion for the prop shaft. While turning under a no load ( load being a torsional twisting force) rotation any pinion will "whine" . When the pinion is under a load, the harmonic isn't right for the "whine" to start.

Making a long story longer, I'm not worried about my "whine". If it starts to grind then that's another story.

If you come up with anything different I'd like to know. [thumbup]

Ken

[tgrumaj]

Looked at the fluids today and all was fine. Power Steering and ATF were OK (Althought my AFT fluid was much higher on the stick than the "hot" level so I'm not sure what that means). My first thought was that the PSF was low but given that this also happens when driving in a straight line that most likely wasn't the issues anyway. Thanks for the insight. I'll keep an eye on it (or ear in this case) to see what develops. Please let me know if you find anything further as will I.

[Tyrant11429]

Well, here's a new one. When driving I am now hearing a whining noise especially when decelerating around 30-40 MPH. It's more of a "WWRRRRRR" noise. Since it will rise and fall in pitch with the car speed my first thought was the tires. I have Nokian WRs and they have been on since November with no problem. I checked tire pressure and that's fine (I run at the recommended pressure of 36 front and 41 rear). I have just noticed this over the past week. Before that everything was quiet...virtually no tire noise. I wonder if this could be a transmission or bevel gear issue? Any thoughts?

There is no change in performance that I can tell, just the increased noise while driving and the "WHRRRRRRRR"noise increasing as I decelerate. At very low speed it isn't noticable at all.

Why do you have your tire pressure so high ? I know the XC are 32 in front 33 in back, I just have my tire pressure 32 all around maybe thats why the ride is so uncomfy, I was going to try to lower mine to 30 all around and than see if my ride is softer, by the way I have pirelli P6 tires 15's H rated :) Oh I notice I hear a noise in my car when I jerk the steering in park I hear like a clunk noise for a sec, I never noticed it before, am thinking my rack and pinion maybe no good, have to check my PS fluid.

[tgrumaj]

The 36 front and 41 rear presure is what is set as standard on the tire presure guidelines shown on the inside of the fuel door. I like to run high in the winter as it increases the traction by focusing more weight on a smaller tread area. In the summer I deflate to the 33 rear, 32 front "alternative" pressure also shown on the fuel door. I've tried both and neither seems to change the "hum" or "whrrrrrr" sound. Based on other feedback I'm wondering if it's a bearing going or the drive sharf is out of line.

[cossie1600]

the 36 and 41 pressure is for 5 passengers. If you drive it that high by yourself, you are going to wear your tires faster

[Beiner]

the 36 and 41 pressure is for 5 passengers. If you drive it that high by yourself, you are going to wear your tires faster

Explain that one to me. Your suggestion would be to lower the tire pressure if you're the only one in the vehicle therefore lowering the curb weight of the vehicle. Doesn't lowering the pressure in the tires allow for more surface of the tire to contact the road and allow more flex of the tire therefore causing more heat which leads to more wear on the tire? Why then, do tire manufacturers have a recommended tire pressure? Or is that just for our peace of mind?

[BillAileo]

I think you will find that the Volvo recommendations on tire pressure generally have two configurations: one for a lightly loaded car and one for a full load. At least that's the case for our Volvos, and the former (lightly loaded) pressures are lower than the latter. I would guess that the figures are an attempt to produce roughly the same ground contact area in both circumstances.

Bill

[cossie1600]

Pressure is used to support the weight of the vehicle. The higher the pressure, the higher the load the car can carry as the tire is stronger. The problem you don;t want to use pressure too high is that you lose grip as you increase your tire pressure (after you hit the max. operating temperature), you would also run into the problem of wearing just the center of the tire. That's the reason to stick with whatever they recommend from the factory unless you can prove that other pressures are better.

[tgrumaj]

Well I took it to my indy mechanic today who said it was a Strut bearing that was worn out and needed to be replaced. (Passenger side). I must admit after reading all the threads on this board it sure sounded like a wheel bearing. The noise comes when I am at speeds above 40mph and is especially strong when decelerating below 40mph and when turning the wheel slightly to the right (toward the passanger side). Not sure why I would hear a "whrrrrrrr" sound when driving from a strut bearing but in either case that what he diagnosed. He didn't have the part as it was late in the day and no time to order. I'll take it back Wed and have the work done and see if he's right. Anyone have problems with a strut bearing before? Similar symptoms?

[tgrumaj]

Final verdict and fix was a drivers side wheel bearing (needed to replace the entire wheel hub assmebly). The noise and descirption are "right on" other threads on this site and discusion of wheel bearing problems at Bay13 on the Brickboard. If I turned right then there was more noise pointing to the drivers side bearing. Nice to have the fix down before going into the dealer. Cost by the way was an exhorbitant $438 US to replace a hub assembly.

[cossie1600]

they are like $150 for the hub and cant be more than 2 hours for labor. I had mine changed in 1.5 hours

[Tyrant11429]

I had that problem with one of my other cars would hear a whistle time whining noise sometimes, knew it was my wheel bearing, I changed the whole hub and never heard that noise again.