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Discussion Starter #1 (Edited)
So far I've found it very frustrating finding the type of info I'd like.... so since I've purchased the factory manuals, as I encounter difficulties I'll be posting pictures to aid descriptions..... I hope this will be an ongoing link that I will update.

My first contribution is to alignment... or actually the parts involved in alignment

Whooooo Hoooooooo



Above is the scan of the lower suspension of the IS300. Please note the different colored arrows. The RED arrows are pointing to the PRIMARY parts that contribute to CASTER. The BLUE arrows are pointing to the PRIMARY parts that contribute(in this case - allow adjustment) to CAMBER. The GREEN arrow is pointing to the PRIMARY contributor(adjuster) to TOE.

For the folks who have hit a pot hole... and they find their caster is now out of specification, 90+% of the time one of the red marked items will be the culprit. I've spoken with 3 Lexus dealers and "No. 2 suspension arm" tends to be the failure point (most often replaced when a caster issue is found) The lower front brace can and DOES bend too! That may seem like bad news... but in the end it is easier to replace parts then to straighten the chassis.....

I've just had an alignment and I find that the right front caster is at 3.9. The spec is between 5.6 to 6.6, so there is a substantial difference. I'm going to a known reputable frame shop and I believe the "No 2 Suspension arm" on my right front will prove to be bent. I'll post more as I find out
 

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Discussion Starter #2
Quick update.....

The car spent 8 HOURS on the alignment rack!!!!


We measured from 16 points - as far as we can tell the chassis isn't bent There are no tweaks in the front subframe, or support brace. The lower control arms(BOTH) each appeared to match their respective arms on the opposite side, and yet the passenger side had a caster reading of 3.9. (spec is min 5.5 to 6.5)

Now if you remember from my earliest post(different thread) that I had all the service records from the local Lexus dealer..... WELLLLLLLLLLL.... it appears that they(Lexus of Portland) contributed to my cars rack time(and maybe the Lexus dealer wasn't the best place for service...?????....???) The right rear toe in had been OVERTIGHTENED bending the jig(frame socket) and the eccentric bolt SOME. What the result was.... once loosened just a bit... the rear toe (popped) went to 3.3 degrees! (spec is .05)

The guys had seen this before, and they were able to get the mount square enough again to get the eceentric to ride PROPERLY in its path. The rear toe was set to .05

Back to the caster issue. With no sign of frame damage and what appeared to be no sign of lower control arm damage(over 3 hours of inspection and measuring)... all that we could figure was BOTH arms responded(bent) ever so slightly, accounting for the low caster reading. The pair of arms sell for close to $400, and so my guy offered me a lower cost option.... he set up the lower arm into a press and bent just the end where the balljoint mounts... a total of 3mm forward. The alignment and all the specs are within parameters....

Well... Final alignment... camber is 0 on the left and -.1 on the right, toe is -.05 each side, caster is 6.5 on the left, and now instead of 3.9... the caster is at 6.0 on the right
 

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Well... Final alignment... camber is 0 on the left and -.1 on the right, toe is -.05 each side, caster is 6.5 on the left, and now instead of 3.9... the caster is at 6.0 on the right
It will be interesting to see if you still get excess inner tread wear on your front tires with those toe settings. As I mentioned in another thread, I was having the inner wear problem until we went to much more toe-in on the fronts (but still within Lexus specs). Keep an eye on it and let us know!

Stan
 

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Discussion Starter #4
Week later......

I DON'T like bent parts on my cars.... I called Sewell, told Reagan about my delimma... she responded with great pricing and great service. New parts on the way... new shop already set-up... the new shop KNOWS bending stuff to compensate... because he can't find the REAL cause..... is NOT AN OPTION!!!


ANYTHING else is just the wrong way to do it........




OH.......... good news for those with speed bump squeak.... I KNOW the cause... AND I have an effective solution!!!!



This spray grease comes out of the can like a silicone, or other liquified solution, BUT as it "dries" it transforms into a sticky waterproof grease.

Ok, that is the product, now for WHERE you spray it....... LOOOK at the view at the top of this thread.... "No.1 Lower Suspension Arm"... there is something NOT shown there that IS shown in the parts view....



See 48657A it is called the "Front Lower Arm Bush Stopper" It is made from rubber. Ok, now look back at the view at the top, the lower control arm fits between the blue arrows... that washer, 48657A, rides directly inside the channel flat against the steel of the cross member. The bushing squeaks while rotating(like over a speed bump)

Spraying the HHS 2000 above the bushing while using a DULL blade type tool used to allow the spray grease to run into the bushing contact area will remove the speed bump squeak.
 
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