New noise: rhythmic whirring

[grambo]

Trying to diagnose a new noise and need a little help. Our 1990 2wd westy has a rhythmic whirring noise that sounds mechanical and increases in speed and pitch with rotation of the wheels. It's hard to isolate where the noise is coming from, but it seems louder at the front. In neutral (coasting) the noise will decrease in speed/pitch with decreasing vehicle speed, and stops when vehicle is not moving (idling or revving engine). I asked our mechanic about it, and he thought it was just from our new tires (BFG all terrain). But the noise started after about 1k miles on the tires, so that seems unlikely.

A recent long trip gave us another clue: when turning sharply to the left at driving speeds, the noise either goes away or is greatly diminished. When turning sharply to the right at similar speeds, the noise is still present. This leads me to believe it is something with the driver's side front wheel. Front wheel bearings were serviced 6k/3 years ago. Could it be the front left wheel bearing? Any other ideas?

[t3 kopf]

First check that one of your rear axle nuts hasnt come loose. That happened to me once even with the cotter pin in there. Retourquing it solved it.
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'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[Ahwahnee]

Driving along close to a tall wall (often found in back of big box stores like WalMart & Home Depot) with windows down you can usually pin point the location better.

I would at least raise the fron and give the wheels a shake (3:00-9:00 and 6:00-12:00) to note movement (there will be some in the 6-12 direction).

[grambo]

Thanks for the replies so far. I'll check the axle nuts, and especially the play in wheels when jacked up- I had forgotten about that test. Below are some photos of our latest trip.

[j_dirge]

After you check play in the wheels (bearings).. Try this..

Go for a 10 minute drive.
Pull over..
Do a finger/palm touch test on each hub..
Do any feel warmer/hotter than others?
(be careful! as a bad hub or draggin brake can get damned hot!)

If so, you may have isolated your source.. and it could be a wheel bearing, a warped disc (front) or warped drum (rear).

Each will generate more heat than normal from friction.


To isolate a potential bad tire.. Rotate in a spare to each corner.. one at a time. Test drive between each rotation.
If after all 4 have been swapped and the noise continues throughout.. you have eliminated an out of round tire or a tread/ply issue.
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-89 GL Westy, SVX.. finally.

-57 pan f/g buggy with a 67 pancake Type 3 "S"
"Jimi Hendrix owned one. Richard Nixon did not"
-Grand Tour, Season 1, episodes 4 and 5