I have a 1998 Avalon that I bought new. It has about 50k miles and has been well maintained. The only major service has been a timing belt/water pump change about 6 months ago. First, I want to apologize for the length of this posting. Second, I am learning how difficult it can be to determine the source of noise that is coming from a car. A couple of months ago I noticed a noise that appeared to be coming from the rear of the car. It sounded to me like ?tire road noise? or maybe like the noise you would hear if you were running snow tires on dry payment. The noise was in sync with the speed of the car ? not related to engine speed or to transmission gear selected. The noise continued when the transmission was placed in neutral and the car was coasting. I think the noise either doesn?t change or changes very little when you turn right or left. There is no change when you apply the brakes. It was getting a little louder over a period of several weeks. I tried everything I could think of to determine the source of the noise. I rotated the tires ? no change. The tires are Michelin and have had them for about 2 years. I removed the bottom part of the back seat and rode in the backseat while my wife drove the car. I thought the noise was coming from the right rear, but could not be sure. I wanted to check the rear pads and bearings, so I pulled both rear calipers and rotors ? all seemed normal ? brake pads were good. I backed off on the parking brake shoes to make sure they were not the source of the noise. When I turned the axel hubs, there was no play and they seemed to rotate smoothly. I wasn?t sure what they were supposed to feel like. I also removed the front calipers and rotors. Everything looked good. I checked the front wheels for play, but there was none.
I took the car to a Toyota dealer and asked them to try to find the source of the noise. They kept it a day or two - checked it out and said I had a bad right rear wheel bearing. I decided to replace the axel hubs on both sides. I tried to buy quality parts so I bought two new Timken axel hubs. I assumed they were quality because of the price. I verified on several different web sites the model that I needed. When they came in, they were exactly like the ones on the car, except I couldn?t believe how easy they were to turn. They required 1/5 of the effort to spin them as compared to the old ones. I installed them and just knew that I had my problem fixed.
Dang ? after installing the new axel hubs, I still have the noise, but it seems to be slightly different now. It now has a slightly higher pitch and sounds more like a whine and is still in sync with the car speed. I can hear it easily at just about any cruising speed and can hear it when slowing down to about 10 MPH. It is more pronounced when the windows are closed.
It still seems to be coming from the rear, but I could be mistaken. I guess it could be a front wheel bearing or something else. When I installed the new axel hubs, I noticed that there wasn?t much grease in them. It was easy to see into the bearings. Should I add grease and what type of grease do I add. I?m at the point of big time frustration. I would really appreciate some suggestions to help me find the source of the noise. Thanks for any help!