DrVlikhell

The car is an 01 with 190k miles on it. Just bought it a few weeks ago and at that time I noticed it had a very slight whirring type noise coming from the rear which I thought could be the tires. But since then it's gotten much worse and there's no way it's the tires being this loud and gotten this much worse in such a short time.

The noise increases and decreases with speed, regardless of what the engine is doing and regardless of whether or not I'm braking. It also changes pitch as the car goes faster, but never gets to a high frequency pitch, it's always a lower frequency droning/whirring sound. It definitely sounds like it's coming from the rear. It also doesn't change when I take corners, like regular corners in a neighborhood. It doesn't actually make a vibration in the car as far as I can feel, but it sounds like a vibration type of noise if that makes sense.

I'm thinking possibly the driveshaft center support bearing, a driveshaft coupling (aka guibo), or the rear differential itself. Someone in another post for a similar issue said possibly the transmission mount, but I feel like it's farther back than that. Also thinking it's probably not the rear wheel bearings since it doesn't change around corners. Am I correct in my thinking, and/or is there anything else I should look at while I have the car off the ground? This thing is a heavy beast and I don't want to lift it more times than I have to.

DrVlikhell

I just tried to check the above mentioned parts, but everything is so tucked up into the floor and above the exhaust that I couldn't even get my hands in there to poke or prod at anything. I need to get the car higher, but my jack stands have the small head on them which will crush the pinch weld area if I try to use them there. Going to have to build some ramps I guess. I was able to check the rear wheel bearings, but as I figured, they were tight and have no play at all.

Gronemus

How did you check the bearings? This video is worth the watch...

DrVlikhell

I lifted the rear from the center to get both wheels up, then spun them in both directions and didn't get any noise or harsh feelings in the wheel on either one. Then I gave each of them the 12-6 and 3-9 shake, rotated 1/4 turn and repeated, did that three times, no looseness anywhere.

I watched the video and will try his coil spring method tomorrow.

DrVlikhell

I checked according to the video and didn't feel or hear anything still. I spoke with a local independent Lexus garage and they were very dismissive of both methods saying that you have to check with a stethoscope. I have a stethoscope so I may give that a try. I talked to another Lexus garage and the guy was a lot nicer and said any rear noise is likely the wheel bearings and very rarely the differential. Neither one of them mentioned the driveshaft carrier bearing. The second shop also said cost of doing a single rear wheel bearing is $1000, so I'll definitely be doing that myself it that's the culprit.

BigBoomer

Wheel bearings. I just had mine done. Front left died at 135k miles, rear right at 140k miles. Both times I had both sides replaced.
Cost me 1200UKP ($1500) for both front and about the same for both rear. OEM parts were half of the cost each time.

DrVlikhell

I ordered a Timken hub and it came with a Koyo bearing in it. I'm using rkw77080's guide, as well as a couple videos, and I started working on it tonight. Everything went surprisingly well until the part where you remove the four bolts holding the hub assembly on. This is supposed to be one of the more straight forward parts, but I absolutely can not fit a socket onto any of the bolts. The reluctor ring on the axle is in the way and the socket will only sit crooked on the bolts, just asking to round them off. I tried pushing the axle in more with my gear puller but I'm afraid of damaging the axle if I push too far/hard.

Currently my options seem to be, A: Disassemble enough of the suspension pieces to get the hub to move away from the axle to make room for the socket, or B: Grind down a socket to make it shorter so that it fits past the reluctor ring. Since I have four or five 17mm sockets and a dremel, I'm probably going to try option B first. The shortest of my 17mm sockets are all the same height and width at 26mm tall and 23.5mm wide, with 13mm of depth inside the socket to work with.

Alternatively, the passenger side axle is the one I'm working with and it seems to be held onto the differential with six hex bolts. If I remove the bolts, will the axle just drop down so I can slide it back to make room for a socket on the hub bolts?

I'm going to pick this back up tomorrow evening, if anyone has any other ideas or input before then I'd really like to hear it.

pmesfun

Yes remove those bolts and drop the axle shaft. You should have plenty of room to remove the reluctor wheel shield. You have to remove it to get to the bolts. That guide is for 04-06 where the axle splines into the diff.

DrVlikhell

The reluctor shield isn't an issue, I was able to get that to come loose. It's the reluctor wheel itself that's in the way. I cut about 5mm off of a 17mm socket and was able to get the bolts off that way. However, I think removing/lowering the axle is still the way to go moving forward since it was hard to get the bolts out after loosening them. In fact, I couldn't use the socket to do more than loosen them a couple turns because it would get stuck against the reluctor wheel as the bolt pushed the socket backwards. To remove them I had to spin them with my finger tips and then wiggle the reluctor shield to get them to come out. There must be some difference in how far the axles move in/out between the earlier and later cars, because every picture/video I've seen shows far more space than I have to work with.

DrVlikhell

Finally put that job away. The car rolls nice and quiet now. I still wasn't exactly sure it was the wheel bearing until I actually got it out and spun it in my hand. Noisy little fella. It's weird how these fail, not a bit of slop or play in the thing, just some growling noises coming from the inside. The sound was so loud at speed that I was concerned it might be the drivers side wheel bearing too, but nope, just the one. I may do the other side later, at a more convenient time... after summer is over. But maybe not, no way to tell if that one has already been replaced or if it's original.

I wonder how hard it would be to replace just the bearing now that I have the hub out to play with.

So all in, $250 for the hub with Koyo bearing including tax, $20 for a puller and $10 for a 32mm socket. Less than $300, so I saved $700 by not taking it to a local shop. I'll take it.