Markkosz

Nad1370

Markkosz

salimshah

Before you dig into more intricate things like tone ring and sensors, check the quality of tires, condition of tread and inflation level.

Salim

Nad1370

Try disabling the traction control and see if it still "judders".

tllee

Hi Markkosz,

I know this is an old thread but my 02 RX300 has the same "judder" condition as yours. Do you find any answer or solution? I am highly suspect that's torque converter shudder problem but the problem only happened when start moving from stop and under light throttle. If you see my reply, please give some feedback. Thank.

carguy07

Pull the connector off the abs and see if it goes away.

tllee

That's one thing I am going to try but I fairly sure my ABS wasn't activated(my feeling sure is not fast enough to catch on computer's response). I already changed my transmission fluid and filter(it was changed 12000 miles ago and my transmission run smoothly)but it's still happening. BTW, no code, no light on, I scan it several times.

salimshah

obdII codes are typically emission issues [sub set of all problems].

Salim

tllee

Anybody could tell me how it feel like when VSC activated? I never have that experience so I need to figure out that. When VSC activated, it will do two things, utilize the ABS to brake wheel and reduce engine output to gain control. I know how it feel when ABS activated but no idea about the reduce engine output. I suspect the transmission turbine speed sensor may act up. That's reason why I need to know.

carguy07

You won't feel anything other than the ABS activating. You can disable the ABS in seconds by disconnecting the harness. Do this and see what happens... or keep speculating about other things that rarely go wrong.

tllee

Thank for the advice. I am with you, I hate to throw in parts and money for problem that I am not sure. I will disable ABS by remove the relay or harness and give it a try. I just want to clean up the two transmission sensors which are use magnetic to detect the speed, it will also suck in a lot of metal particles inside the transmission. That could make them a little inaccurate and cause weird problem(computer still recognize them OK, so no light yet). BTW, this shudder problem barely happen, probably once or twice on a long trip, sometimes it don't act up at all, I need to drive a long time in order to sure I find the solution. I'll report back as soon as I find out(The temperature here is going down to 20s)

tllee

I finally confirm that my VSC was activated on wrong occasions. I connected my mini VCI and run VSC/ABS/Track data list on Techstream while I was driving around, I recorded the whole incident.
But it puzzle me more, the shudder happened when car start moving from 0-3 mile/hr , the ABS pump is on, the right rear and front left solenoids are on, one track control solenoid is on too.
All my wheel speed sensors work fine, speeds shown on 4 wheels almost are same except when make turn. The biggest difference is 0.6 m/h and all report speed at same time. Steering Angle sensor seem working fine with yaw sensor.
But I have no any experience on this data, anybody can give me some ideas where to look? It will be very appreciated.

Nad1370

You could possibly have broken reluctor rings.
My ABS would briefly kick on right before i come to a stop or sometimes coming off a stop. (no codes where stored for me but some members here did have have a code(s))
Broken reluctor (tone) rings are common on older/higher mileage RX's.
I never did try to find which ring broke but when i did my L / R wheel bearing, boom...that reluctor ring was split due to rust on that axle.
I ended up just disabling my ABS.

tllee

Yes, it's one of the possibilities. I look at my data list from Techstream, no particular sensor act abnormal. I will give it another try, to get more data, the most difficult thing is to find a straight road and can drive very slow for 2 mins(I'm in northern NJ, close to NYC), that could trigger my VSC more easy. My car only act up under 4 MPH and moving slow from a complete stop, no brake pedal. It could happen next second or not in next 24 hours.
It's a pity that you didn't change your tone ring or CV axle when you have the best opportunity. The axles listed on Rockauto has very good prices, the tone ring even cheaper. From the pictures on Rockauto website, I can tell the tone ring is actually sit on two pieces of stainless rings which can be separated in order to remove and install tone ring(my reasonable guess).