Freaky Noise On Cornering

[91L3xus]

OK, I know many members have been shunned in the past for not being extremely specific with the description of their noise or problem or whatever, so here goes:

Today I was exiting the George Washington Parkway (the McLean exit, I'm sure no one here knows what it's like)- a ramp that starts off on flat ground, then goes uphill while bending to the right, until it does a complete 270* turn to get going on the road above. I entered this turn at around 30 MPH, what I normally hit it at, sometimes faster in my 4Runner, and about 1/3 the way up the ramp, I heard and felt a loud "Kathunk kathunk kathunk" coming from the left front of the car. It also caused my car to jolt for every "kathunk", which I think happened about 6 or 7 times.

This noise and feeling really scared the crap out of me, and thought my front left wheel was about to fall out from under me. I'm not suspension or driveline savvy at all, but any help would be greatly appreciated, since I did just put $1200 in miscellaneous repairs into it, and this problem must've been encountered in the 3 days/50 miles they drove my car around.

Thanks.

[SKperformance]

Probable expansion joints in the road causing the noise and bump.If you have worn ball joints it will also cause the wheel to reangle needing you to correct the steeringwheel to keep the same angle of direction.

[91L3xus]

There aren't any expansion joints on this ramp, atl east visible ones I'm used to. It's completely smooth flat asphalt. But I do know that expansion joints cause my front wheels to skip when I'm driving into DC, especially over bridges.

[steviej]

First question:

Is the sound reproducible or did it only happen this one time. Go back to the exit and see if you can make it happen again.

Jack the front end up and look under. check the rubber boots that cover the CV joints. Make sure they are intact and not ripped or torn. If they are, see if grease sprayed everywhere under the car around that boot.

If you are following me, I am thinking CV joint problems.

Find a ramp that goes in the opposite direction and hit it at the same conditions as when you heard the noise. See if you can hear the noise again.

Find a large parking lot that is wide open, open your windows, start making a gradual circle and each time you go around, tighten the circle up. Listen to see if you can recreate the "kathunk". Do this in both directions.

Second question:

Are you applying the brakes at all when you are on the ramp?

I ask because in a previous post, here, you speak of a kthump, kthump, when you apply the brakes. Is this the same sound?

I would venture that something is a miss with you new brembo rotors. Maybe as the suspension compresses (brakes being applied) then something is hitting the rotor? I reaching here.

steviej

[91L3xus]

Stevie thanks for the reply. I have not been able to take a look under the car yet, but I was able to recreate the sound made on the ramp from the front left. I did this by exiting the same way as before, and got the same sound and feeling though the floorboard and steering wheel. I was not applying the brakes. Over this weekend I'll take the car to an empty lot and try to recreate the sound, but turning left instead of right.

The sound (and pulsation) that I got from the brakes was from the rear, which was diagnosed as my rotors being slightly out of round, and if they were machined, they would barely be above the minimum thickness requirement. The mechanic said that I should not mess with the brakes, and get the 5-10,000 miles he estimated were left in them. (My rotors were not replaced, nor were the pads, just new brake fluid).

My car gets inspected in December, so I'll update you then with the exact running operation of the car; I've seen the previous ones and they seemed to all check out fine. Suprising, since Virginia has strict inspection laws.

[ArmyofOne]

Stevie thanks for the reply.  I have not been able to take a look under the car yet, but I was able to recreate the sound made on the ramp from the front left.  I did this by exiting the same way as before, and got the same sound and feeling though the floorboard and steering wheel.  I was not applying the brakes.  Over this weekend I'll take the car to an empty lot and try to recreate the sound, but turning left instead of right.

The sound (and pulsation) that I got from the brakes was from the rear, which was diagnosed as my rotors being slightly out of round, and if they were machined, they would barely be above the minimum thickness requirement.  The mechanic said that I should not mess with the brakes, and get the 5-10,000 miles he estimated were left in them.  (My rotors were not replaced, nor were the pads, just new brake fluid).

My car gets inspected in December, so I'll update you then with the exact running operation of the car; I've seen the previous ones and they seemed to all check out fine.  Suprising, since Virginia has strict inspection laws.

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does it feel like the car is skipping across the lane? if so, that is ball joints, its a signature sign. if it doesnt than its CV joints. remember, on CV Joints, replace the entire shaft. and any shaft you gcan get at o'rielly's auto parts, advance auto, or autozone will work just as good as the original in this case. i think i paid somewhere around $150 for all the parts. not sure though cause its been awile. from lexus (if you can even find them, i had trouble fidning lexus OEM Axles on my 1990 ES250) they will run about $300 EACH. so get the aftermarket. they come with a lifetiem warranty...and a good mechanic should only charge $250-$300 labor or so for Removal and install of both sides.

as for the ball joints, if this si the case, they are $36 a piece here from toyota:

http://www.discounttoyotaparts.com