[Nachonater]

Hi everyone, wanted to reach out and get some help diagnosing a problem I've been chasing with my car the last week or so. One night on the way home from work my car suddenly started shaking at certain speeds, it's the worst at ~22 and ~70-75, but at some speeds it doesn't shake at all (for example, can drive at 65 with no shaking). There are no strange noises so wanted to start looking at other options before going straight to wheel bearings since noise seems to be the most common symptom of a bad bearing based on my searches. Anyways, here's what I've done:

• Got wheels balanced/rotated at Costco. Tech said two of my rims were bent. Vibration wasn't fixed.
• Bought new wheels (RPF1's, was considering buying anyways) and had the tires swapped over since they still have 90% tread. Vibration wasn't fixed, although after driving home it seemed like the low speed vibration was getting better.
• Jacked the car up today and did a nut/bolt check to make sure it wasn't something coming loose from the manual swap. Everything seemed fine.
• Pulled on the front wheels while jacked up, no play at all.
• Pulled on the rear wheels, seems like there's a little bit of play, which has me suspecting wheel bearings. Not sure if it could be a ball joint or bushing though, and not sure what the best way to check that is.

Long story short, just wondering if it sounds like my wheel bearing is likely the problem or if it could possibly be a worn out bushing or something similar in the rear that's causing my rear hub to have some play. Hoping it isn't the bearing cuz we have a week of rain coming up so I can't ride the motorcycle and need the Lexus to get to work. Thanks for any advice!

 

[Gospdracer90]

I have 230k on my car and I never changed the rear bearings but I've done the fronts like 4 times. I don't recall a vibration when driving I only recall there being a noise so I don't believe its the bearing.
I don't know what it could be but I would just suggest taking a look at your control arm bushings and see how dried out or cracked they are.
Do you mainly feel it in the steering wheel or is the whole car vibrating?

 

[Nachonater]

It’s the whole car. I got under the front and all the bushings feel solid/look ok, admittedly once I felt the play in the rear I just said “ah shit wheel bearings” and didn’t really check to see what was really moving.

 

[ill_mannered]

front lower No. 2 area bushings are pretty common to wear out. Might double check those.

 

[Pnut00]

Ive had cheap tires give me a similar result, even showed ok on a balance. Ended up the tire was delaminating.

 

[Nachonater]

I'll double check that front bushing, but I'm thinking it might be the rear axle carrier bushing- found a video of someone else's blown one and seems similar to what I was hearing when pushing/pulling the rear wheel. Won't be able to confirm tonight, but will check tomorrow.
Tires are fairly new Michelins, so would hope that isn't the issue but I did hit a nasty pothole in June that blistered a tire which then got warranty replaced- possible the other tire that was on that side is delaminating or something. I'd hope that was caught during the dismount/mount on the new wheels but who knows.
Interesting enough, had to drive tonight and noticed the magnitude of shaking is less than before, and the 75mph shake seems to be gone. It's mainly just at ~25 and it will immediately stop once you get down to 20mph on the dot. being in gear or neutral makes no difference. Also there's no vibration in the steering wheel at all.

 

[Nachonater]

Well, I’m an idiot
Jacked the rear up to take a video of shaking the rear wheels, and decided to check the driveshaft to diff bolts. All 4 were loose. Took off the plastic tray to get access and one of the bolts from between the two driveshafts was laying in there. So 2/4 loose and one missing. Put loctite on all of them and tightened back up, shake is gone!

 

[Pnut00]

Nice to find an easy fix though!