UCrazyKid

So I had the slight pull to the right everyone talks about. I had it worked on last year they placed one caster bracket (block) this time it is still doing it, they put a caster block on the other side (right).

The car is tracking straight, but I'm not sure I like the specs. I spoke directly with the alignment guy (dealer) and he says he has done all he can do with the limited to no adjustability in the suspension.

What are your thoughts? a little more toe out in the front? He told me he dialed it out to save tires, I get that, but I dont want to give up much turn in on the ISF. The issue I think is that they can not get even camber in the from Left to Right. They tell me the subframe cannot be adjusted because there are guide dowels in it to align it with the frame. (I had not heard this before). The shocks are not adjustable at the top either. What more can be done? Is this a manufacturing defect that the car can not be aligned to meet specs? I talked to the Service Manager and he told me he would get a factory field tech out to look at it if I want (not a rep, a real tech).

Thoughts? I know a little about alignment but would never pretend to know too much. Hoping some of the other technical racer types can chime in.

Thanks!

Andy

D2M

iTrader: (2)

i had the same problem.. what i did was jack the car up and loosen the 4 front subframe bolts and moove the whole subframe over to the right by about 1.5mm, that evened out the camber on both sides.. you will need to get a lower control arm bushing (lexus offeres many specs) to fix the caster on the left i think spec is above 8°.. uneven caster will make your car pull.. i cant beleve toyota didnt provide any adjustment for those setting on a performance car like this.. WTF

UCrazyKid

So you were really able to do this? The tech I talked to today told me that the subframe could not be moved due to the alignment dowels. 1.5mm is enough to do the trick? I guess I"m going to have to go back and question whether he even tried moving the subframe. What a headache

D2M

iTrader: (2)

the isf does not have alignment dowels in the front subframe, once the bolts are loose you can easily pry the subframe in either direction. it took me about 30min in my garage.. now my camber is perfect on both sides.. looking at your camber spec i think 1.5mm to the right will do the job.. mine was out by .5° left to right as well.. just loosen the 4 subframe bolts and towards the rear of the subframe there are tow hooks atached to the rear subframe bolts and to the body of the car by 2 14mm bolts , you will need to loosen these as well. moove the front of the subframe over then snug one front bolt then moove the rear over that same amount and tighten everything. no need to remove anything. on a lift its about a 15min job, no big deal..

FIGS

iTrader: (11)

Yeah the uneven caster is where your problem is so the subframe could be slightly skewed. Also did you check the specs with you in the car? How much do you weigh? This can skew things as well, maybe not to the extreme that it pulls, but the car will toe in under compression since the steering rack is to the front of the wheels.

Just as a refresher, caster angle is the relationship between the two ball joint centers. If your subframe is slide backward or forward on one side this angle will change.


I am still working on adjustable upper control arms that will mitigate this and still be track duty.

Fig

D2M

iTrader: (2)

by changing the circled bushing you can adjust the caster on the IS-F.. lexus offers 3 offset bushing options.. so tweak your subframe to the right and replace the left bushing, set the toe and your done..

UCrazyKid

We have already done the caster bushings on both sides (see OP). My hope is to get them to shift the subframe and realign.

D2M

iTrader: (2)

wow. hopefully they installed the right bushings on the right sides.. 1° of caster differential is a lot.. idk if you will be able to make that up with the subframe.. was the car ever in an accident?

UCrazyKid

The car has never been in an accident or so much as hit a bad pothole or joint in the road. The 1.1 degree difference is their attempt to make it go straight with the camber issues, etc. they mentioned using a different bushing next time as I guess they come in 3 sizes.

What sucks is that I am left troubleshooting this instead of the technician doing their job. Lexus you fail.

Reciprocal

I agree. I was also left to troubleshoot this. Lobuxracer suggested my numbers were not bad, so I'm dropping the issue, but it left a bad taste.

They are too interested in making a buck off a quick alignment, and know that once they get into sub-frame adjustments, it's trial and error, and time consuming parts swapping after that. So they are loathe to touch anything within spec, and even things outside the spec they will say aren't adjustable or don't affect tire wear or safety therefore don't need further work.

What's pathetic, is they readily point to the upper and lower limits for toe to sell you an alignment, but anything else, camber or caster, if it's close though still out, they ignore them. So the numbers basically don't mean anything to them.

D2M

iTrader: (2)

^^ sad but true ^^

bottom line you have to diy..

lobuxracer

iTrader: (2)

Sorry I didn't see this earlier...

Yeah, your car is screaming for a subframe adjustment. Both your cross camber and cross caster are horrible and I'd call Lexus to complain about this until they get it right. The car does NOT meet their own specs with a 1.1 degree cross caster. I'm certain it would be vastly improved with the subframe adjusted.

Too bad you're not in the ATL, we could do it at my house...

carchitect

iTrader: (1)

I have a feeling that either the lower arm or/and crossmember are slightly tweaked. The reason I'm saying this is by analysing the angles we have on the alignment sheet. Your lower arm has an "L" shape design to it. The rear is held with a caster bracket. The front is bolted to the front crossmember and during a severe bump, it gets the crap hammered out of it. If the bump is severe enough, this area will be tweaked. When that happens the lower arm pivot will be forced outwards. The camber and caster would become more negative.

The diagnosis for this would be setback inspection. This is another angle that is available on the alignment machine. It is located in "additional measurement section". It takes less than a minute to find it. It displays all tires actual contact patch and displays the difference of setback, whel base difference, and thrust angle.

Although the front crossmember can be shifted to equialize the camber, the caster would still be affected. You maybe able to advance the caster on one side and reduce the caster on the other side via positive and negative brackets and it may or may not take care of it.

Currently, the front camber has a drift to the right. The caster is causing a drift to the left and equalizing it. The suspension is still out of whack (not significantly though) and it may not adversely affect tire wear.

Please note that if your crossmember and/or lower arm is tweaked, using an adjustable upper arm or ball joint to bring your caster into spec may make matters worse. Since it will shift the upper ball joint rearwards to increase caster when the lower arm is already shifted rearwards, the end result would be an increased setback on one side and even though the caster, camber and toe will be perfectly in line, the vehicle will drift to one side.

Evil Teo

iTrader: (13)

what would be the best way to solve this?

lobuxracer

iTrader: (2)

Get the specs from the factory service manual and measure the relevant pieces. All the specs are there.