Salim- Maybe we both can learn something from this. It's a good day for me when I learn something, so this is a good day!
I had my DIL's RX for a few days while my son and DIL were on vacation. I crawled under the car to look around this afternoon. The rear DOES have eccentric bolts (cam washers) on the rear inner bolt for the lower support rods. Both cam washers were at ALMOST dead center (half a click off). When I came in I opened the file on my manual on DVD. It covers '99-'03 so I trust they are the same. Obviously toe on rear wheels. In going over what they said for camber adjustments, it is kinda involved. They say to loosen the bolts on the strut to knuckle. Oil them with engine oil. Take the reading on camber and if it is not within specks, go to a special table they have and estimate which one of, I believe 4 special cam bolts that will get you closest to the ideal reading and insert that to change the camber and recheck when tightened. Same thing for camber on the rear. There was no mention of shims. I do not understand, and they do not show you or explain, what this bolt is like or how you get it in the hole, unless they are just progressively smaller to let the knuckle pivot before you tighten the bolts. I have done something similar when I needed a little bit to get the alignment where it needed to be on Mcp. stuts like the Lexus, that have NO adjustment. I simply left the bottom bolt rather snug, took the top bolt out and yanked or pried the knuckle out to proper alignment, used a die grinder with the proper sized bit and carefully carved the hole so that the bolt would JUST go back in. It takes very little, maybe 1/16-3/32 in. to gain what you need normally. Very seldom had to resort to that. So they have Camber both front and back, toe both front and back, but no provision for caster. I wonder how many of those bolts Lexus has ever sold? Probably be able to carry them home in your lunch pail. I would lay a $1000. on the table that there aren't 100 independent shops (non Lexus dealer) of any kind in this country of 300 million people that carry those Lexus camber bolts in stock to be able to do the camber adjustment. Do you think that when they check anyones alignment and it's out of specs a little that they're gonna tell you, you'll have to bring it back later after we order these special bolts? When you see the pigs flying maybe, but not until! I learned something today Salim- I hope we both did.

 

I have lot more to learn and any education I get is very welcome.

What you posted is very educational. I did not even know that "toe-in" applies to the rear ,, specially they being independent.

In my simple mind reasoning. I thought the shims (addition or subtraction) will allow the tire to ride on the inner vs outer edge ... by changing the angle of the strut (left to right). Toe-in adjustment is simply changing the link length to affect the angle of the FRONT to point away or in. Based on this reasoning if the fronts have eccentric bolts one can move the strut to lean forward or backwards.

One member found out various bolts that are offered for making certain adjustments.

My simple thinking goes out f the window if the RX does not allow single axis adjustment.

I have lot to learn.

Salim

 

Hi Salim- As I've said, good day for me when I learn something. The rear toe adjustment IS valuable because because there are times when you need to correct rear "parallel" wheel alignment. I have worked on many (cheaper) cars that don't have it and when they're off a little, you have no way of dealing with it. The one "cam washer" adjustment on the rear inner bolt will deal with that nicely. I remember now that when that discussion was going on before, I too went to aftermarket sources and found the bolts to deal with camber adjustment. I don't quite know how that works because you normally have to use the cam washer approach that is used in the rear toe adjustment. You can't put an eccentric bolt in 3 round holes the size of the bolt(which is what you have- 1 knuckle and 2 strut). The approach I used worked quite well, and wasn't needed often. Frankly, the reason they don't often provide Caster adjustment on cars such as the RX (and many others) is that with todays ability to manufacture to close tolerances, when the vehicle is built to those tolerances in the very precise jigs that are used today (most all cars are unitized), they simply are built right and being unitized, it will almost certainly stay that way for the life of the vehicle- you won't have to worry about it. The camber adjust. is a LITTLE more likely to become more "neg." My experience though is that I have seen many vehicles that have SOME excess camber and it does not affect anything, as you will most of the time have exactly the same on both sides, and it normally causes no tire wear and no driving problems. A lot, if not most FE,FD cars, the torque causes the wheels to become more upright (more toward poss. camb.) when you drive. I have to chuckle, because far more FE alignments are "feel good" adjustments, when the only thing they have the reasonable ability to adjust is toe. They "feel good" about it because they got it checked and didn't realize the FE shop couldn't adjust much of anything anyway. The evidence is in those that had the alignment checked after replacing struts and found that everything was perfect.

Have a great day Salim- as we learn together

As an afterthought- The fact that they have specs for Caster does NOT mean there is any provision for adjusting it. After a collision, it definitely needs to be checked, but shame on the Body and Frame guy if it's not perfect, with all of todays bench frame racks and precise measuring systems, required by the insurance companies. (some unitized cars do have the provision, but the RX, as well as many others does not) Doesn't need it!