Grinding Noise from the Back after Side Collision

Rear wheel bearings are not a normal wear item. They are sealed units and normally require no service or maintenance. The Toyota rear suspension is very simple compared to the front. The rear suspension has no ball joints or drive axles, only the brakes (not "breaks" by the way), and wheel bearings, plus locating arms to hold the wheels in position as the suspension moves. Seems unlikely to me that collision would affect the brakes. They are basically a very simple mechanical device. You didn't say whether you have rear disk or drum brakes, let's assume drum - just check for a bent backing plate - the sheet metal that holds the brake linings. A noise from brakes should appear just turning the wheel with the car in the air, whereas a noise from wheel bearings is usually heard under "load" - that is when the weight of the car is on them. For front wheel bearing diagnosis, the usual method is to move the wheel from side to side while driving to shift the weight of the car from side to side and listen for any changes in noise to see which side makes more noise and replace the wheel bearing on that side. Not sure if a similar method would work for the rear. My guess (just a guess though) would be that both rear wheel bearings should be changed. If one was impacted, so was the other since both rear tires were on the ground both sides received equal force upon impact. Plus you say replacing one side reduced the noise, thus one is led to believe replacing both sides could then eliminate it altogether. Again, rear wheel bearings generally never wear out. The weight on the rear of the car is roughly forty per cent of the total weight of the car, and each side carries half that weight, so with a 3,000 pound car, if my calculations are correct, you only have 600 pounds riding on a wheel bearing - relatively light weight in automotive terms. Ask your Toyota dealer parts department, (most all have computer records now) how many Camry rear wheel bearings they sold last year. I'm guessing very few. So if the rear wheel bearings are bad, it's not your fault or a normal wear item. Plus, with enough impact to damage the door and side panel, the alignment should be checked and adjusted if needed, but should definitely be checked. My Toyota dealer will only do a computerized four wheel alignment because that is the only way you know everything is properly lined up. So that's my guess. Change the other wheel bearing (there's no difference in impact during the collision between sides since the frame "unibody" of the car forms a rigid connection between rear wheels both side receive same impact force therefore if one side is bad, they should both be changed, plus you say changing one helped, and remember they normally do not wear, so you're not responsible for replacement under the theory that they were worn out anyway. Plus do the alignment as a minimum insurance policy and you should be fine unless the alignment shows frame damage beyond the limits of adjustment. Just my opinion, not having seen the car, based on your statements.

If the SUV hit your actual rear road-wheel, the rim would be stuffed as well as the bearing (brinneled tracks in the bearing). The other side would sustain some side-load, but this is much reduced due tire(s) skidding/deforming effectively taking a lot of the shock.

In this situation, I would jack up the rear damaged side and then the other side and get them to spin each road wheel with a suitable device (dynamic wheel balance electric motor would do) so they can check for any run-out or lack of smoothness.Its better to have the rear suspension loaded during this test, so actual road conditions are simulated.

If I had to guess, its either something simple like a mud-flap fouling on the road-wheel or *something* is damaged in the hub or brakes area. Has the car got drum brakes on the rear? If so is the metal dust-cover fouling on the drum,..stuff like that..

I'd also inspect the inside of the effected road wheel specifically looking for rubbing marks on the inside tire-wall due to the tire fouling on its strut. This can be intermittant as the tire side-wall bulges (and starts rubbing on something) over road-undulations then returns to normal.

Dont let the matter drop. Accident damage can be more difficult to analyse than straightforward wear but its not impossible for a good mechanic.

Jason

Thank you very much for your comments, Daniel and Jason. Now, I have more ideas what could have been wrong with the car. I'll take this information to discuss with the collision center and the Toyota dealer.

For more information, my rear brakes (thanks for correcting me) are drum. I had all brakes serviced about a year ago. The last inspection was that I had about 90% left for all wheels. I also took the car to Les Schawb for a free rear brake inspection. They took apart the drum brakes and inspected, not a test drive. They found nothing wrong and said they were like brand new. I don't know whatelse they did.

The followings are urls containing some photos of the car after collision.

NT

Just to add my 2 cents worth on this topic. I've an accident a number of years ago when my front wheel was hit. After everything was fixed, I can hear a grinding sound from the wheel. Turn out it was the dust cover on the front brake touching the rotor. By bending the dust cover slightly away from the rotor, the sound disappeared. In your case, it could be some moving part touches a fixed part on the wheel. If this is the case, you should be able to see some marks on the fixed part.

which maybe where the wheel kept turning during the accident. The noise you describe may be tire-damage (some sidewall delamination perhaps) I would try a different wheel and tire on both sides, the damaged side first, then the other to cover all bases.

The brake guy said all looked OK inside the drum,..that limits the scope to road-wheel damage, strut noise, it did cop some side force, try "bouncing" the rear of the car to simulate the noise.

Jason