Ride is harsh during decelration -- possible culprit(s)?

[aubie96]

My 99 lx470 has been acting up of late when I take my foot off the throttle and start decelerating. Around 45mph and going down, left front side has a lot of noise or vibration. Much like an open window does at high speeds. No squeaking here. The brake pads have good bit of life remaining.
Is there a checklist that I can go through to eliminate the culprit? It's not the clunk or ticking noise here. Dug through those threads but nothing I could relate to like that.
I ride stock with michelins and ahc still on. No towing or off-roading either.
Any pointers will be much appreciated.
Regards.

 

[etarasoff]

You didn't mention it but I assume you mean decelerating without brakes.

Could be bad wheel bearings? When you are decelerating, does the condition get worse/better if you turn left/right?

 

[aubie96]

You didn't mention it but I assume you mean decelerating without brakes.

Could be bad wheel bearings? When you are decelerating, does the condition get worse/better if you turn left/right?

Yes, it's only when I am coasting down on a flat road, usually straight. I did not have a chance to experience it during left or right turns though. It's got almost 120k miles now and seriously doubt if bearings were serviced by PO. I did not either in the last 10 months I had it.

When you say bad ball bearings, you mean worn out? Or just that might need repacking? Is there another way to confirm that without really pulling out the bearing?
Thanks.

 

[etarasoff]

You can jack up the wheel and do the grab-n-wiggle test:

http://lmgtfy.com/?q=test+for+bad+wheel+bearing

When you have a chance, while decelerating, just do a quick turn to the left or right (like a lane change on the freeway). Doesn't need to be an extended left or right.

Good luck

 

[aubie96]

You can jack up the wheel and do the grab-n-wiggle test:

http://lmgtfy.com/?q=test+for+bad+wheel+bearing

When you have a chance, while decelerating, just do a quick turn to the left or right (like a lane change on the freeway). Doesn't need to be an extended left or right.

Good luck

I have my work cut out now. Thanks for that lmgtfy link. I needed that kick.

 

[Trunk Monkey]

Could also be a u-joint, they usually make their noise when decelerating.

 

[12guns]

Could also be a u-joint, they usually make their noise when decelerating.

The only u joints we have are on the front and rear drive shafts. Yes it's possible, but not likly unless he can feel the fast vibration of a fast spinning worn out u joint. I would guess bearings need to be cleaned / packed.
Next time the noise comes up, try turning side to side which will put more/less weight on each bearing. Sometimes if the noise comes and goes when you do that, you can narrow your problem down to bearings (that may have been covered in the link as well).