front wheel shaking at down hill braking

[vince_wong]

I have another one of these problem that mechanic seems to have no glue or don’t want to look into detail. My 2004 RX330 front wheel (driver side– I feel) shakes vigorously when slight braking during down hill (>60 mph at 10-20 degree grade). There is no vibration at level road up to 70-80mph and very little afterward. I discussed and took the car to 2 different shops. One suggested a warpped disc so I replaced them with EBC slotted disc which has some chatter noise after installed. Down hill problem not fixed. The 2nd shop do a “forced” balance to the tires. It seems quiet down the shaking at level road a little but not going down hill. The shaking is day & night difference at level ground vs. down hill.
Any idea what should be checked? How to eliminate or confirm struct is the cause? Any suggestion is appreciated.
Thanks You!

Vincent

Topic

[WOTStang]

Which bushing are you seeing that is torn? Can you give us an exact location or a picture? Then i can look up some information and let you know what is needed to replace it.

[vince_wong]

They are 2004 RX330 lower control arm press in bushing. One of LCA bolt is between side motor mount and chasis. The rubber are cracked on both sides. I am worrying about jack up an engine with everything still connected. Never did it before. thanks for advice and checking.

Attachments:

• RX330_bushing-2.jpg
• RX330_bushing-3.jpg

[WOTStang]

“bushing 3” seems to possibly have a significant tear in it on the left side, but its hard to say. the rest look to be just stress cracks in an 11 year old rubber bushing.. however i have replaced a lot of control arms due to bad bushings that didnt look half as bad as this and were bad enough to cause a dangerous pull to one side under braking due to the rubber shifting.. scary experience.. totally intermittent too.

That being said, is your RX330 FWD or AWD? It looks like i can see an axle in ‘bushing 3’ but im not sure. Also, do you have air suspension on this vehicle? Both factors come into play when it comes to the replacement of the control arms.

Edit: I just looked up the replacement procedure for the control arms in Mitchell… It’s not good news, and im stumped at the moment as to why. It’s calling for a labor time of approximately 15 hours for an engine/transmission removal just to replace these control arms! Can anyone else confirm this? It does show a labor time without removing the engine as 3.1 hours for both sides. But im not sure if that’s possible.

I do recall in the past doing a lower control arm on a Toyota Avalon that blocked access to one of the control arm bolts due to the transmission pan being directly in the way.. however i got around this by accessing the top transmission mount, unbolting it, lifting the transmission up for enough to access the bolt and remove the arm.

Ill get back to you on this exactly.. first time i’ve seen a complete engine removal for a lower control arm.. :ohmy: :S

Attachments:

• G00315800.gif

[vince_wong]

Thanks for quick response. It is AWD without air suspension (?) I need to confirm the air suspension part. The symptoms are brake shaking, tire wear like mis-alignment even aligned annually. someone online suggested to loose all mounts and jack up engine to remove side motor mount to access the control arm. I would like to get 2nd or 3rd opinion about jacking the engine with everything attached.

[WOTStang]

Little bit of info here: Ill see what else i can find for you.. Definitely seems like a common problem with the control arms.

http://www.clublexus.com/forums/rx-second-generation/692201-lower-control-arm-rx330.html

[Author]

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