Rx-7Doctor

iTrader: (13)

To recap.

There are "NO' issues with parts or tires as stated.

The Car was originally aligned back in Dec 08 and there was no abnormal tire wear at all.

The wheel bearings are good and the preload is set correctly.

I have to lean towards the alignment issue also as there is nothing else left here. I am still looking for the printout sheet to see how it compares to specs.

Thanks again for everyone's effort in this. :-)

Rx-7Doctor

iTrader: (13)

Found the copy of the alignment sheet.

Good call guys on the Caster issue. The right front is out of specs at 3.3 when the specs are 3.7 to 4.7 and the factory puts it at 4.10 +/- .30. Left side is at 3.8 when there specs are 3.2 -4.2 and the factory states it at 3.4 +/- .30. Also show a maximum permissible difference between sides at +/- .30 degrees.

So it goes back to the alignment shop in the morning and we will see what happens.

I had replaced the strut rod bushings back in Dec as well as the other parts before I took it in for an alignment and did not have this issue until after the alignment.

84stock

iTrader: (5)

Caster issues will not develop tire wear. Ya see caster is the degree in inclination between upper and lower blaajoints. For a good example, look at the positive caster from the front forks of a bicycle (exaggerated though), the wheel always points forward. Negative caster (from bent forks) is what promotes a high speed wobble on a motorcycle. On a side note, since your title makes you a self proclaimed doctor of rx7's, isn't this like a heart surgeon waking you up in the middle of surgery to ask if he should work on the right or left ventrical??

jgrewe

iTrader: (1)

Post #5, please PM me my $20 forum bucks and ****!!!

orion84gsl

iTrader: (5)

Definitly true there Kentetsu. The axle sits ever so slightly, maybe 1/4 - /12 inch to the right. You probably can't tell because your wheels stick out past the fenders. If they don't and you check from side to side you can tell the left side wheel sits furthur inward than the right. Sam noticed this a couple months ago, had us all confused.

jinxed4dub

iTrader: (7)

if its not the caster I'd check in the rearend of the car. maybe your rear is tweaking eather way when you turn and staying where its at till you turn the opposite way.

thunkrd

iTrader: (1)

orion, i'm going to try to do a rear end alignment on my car. I just wish i had an extra set of arms and watts link etc so I could do the work (alignment and bushings) without not being able to drive the car...

DivinDriver

iTrader: (15)

Wasn't it eventually concluded that this was an effect of the inequal Watts design, and ride height? I don't remember where the convo ended up.

j9fd3s

iTrader: (3)

in the US a lot of our roads are crowned, ie not flat. since we drive on the right side, the car will drift right.

to counter this right side drift, they add a little caster to the left side, so on a crowned road it goes straight. on a flat it may not.

j9fd3s

iTrader: (3)

yeah something like that...

ray green

iTrader: (14)

Forgot to mention, the string method will tell you if you rear end is in align too, along with a very precise check on the toe-in. I noticed one of my GSLs was out just a tad, not enough to bother with though (you see this because the string doesn't touch the front and back of the rim at the quite the same place).

Won't tell you about caster, however. But then caster is not adjustable on an FB. What'd you do to that thing anyway Doc to get the caster wacked out?

t_g_farrell

iTrader: (1)

Whoa Ray! Caster and camber are adjusted by rotating the strut mount using the little arrow. The FSM tells you what each postion should result in camber and caster.

ray green

iTrader: (14)

I read somewhere they don't normally need to be adjusted and it's been true for my GSLs over the last 10 years, but in checking the FSM I see caster and camber can be adjusted if necessary. I'd take it to an alignment shop for that. Thanks for the heads up Tim.

DriveFast7

iTrader: (1)

I called caster too, but jgrewe beat me to it.. Please send 5 forum $ and pictures of your ex girlfriend.

jgrewe

iTrader: (1)

Um, correct me if I'm wrong but I used to adjust caster with the tension rods. Since when is caster not adjustable?

BlackWorksInc

I think he meant its not meant to have to be adjusted...

Hyper4mance2k

iTrader: (40)

This will not i repeat WILL NOT happen if you install your springs correctly...
You must loosen every rear link and wats bolt. All 13 of them. All 4 uper link bolts and all 4 lower link bolts and all 5 on the wats link, put the full weight of the car on a 4 corners. Put the front tires on ramps equal to the rear axle on jack stands. Then the car will settle with the axle centered. NOW you can re tighten all your links and watts link to spec and the axle will stay centered at a lower ride hight. It it important that all the bolts are in and the full weight of the car is equally on the suspension before you torque everything for this to work correctly.

IanS

iTrader: (4)

^ Yeah, but seriously who does this?

Rx-7Doctor

iTrader: (13)

Guys, lets stop the debate about if what where and why regarding what can and cannot be adjusted or what causes what as I and most of you already know the cause and effect rules and stick to what we know. :-)

Update-

The alignment guy spent 2 hours today working on the car readjusting the caster with in the factory specs as stated in the FSM.

We also tried variances of the adjustments and he checked the rear end, all of the components and everything we could think of.

Had 2 guys working on it checking for binding, movement, on and on and after the alignment with "Everything" in specs it still does the same thing.

To clarify this. The steering wheel does not have a issue returning to center but the tracking of the vehicle will not return to center if you make a right or left turn. It just keeps drifting to whatever direction you turned last. There is no "physical" pull felt in the steering wheel as you are driving.

My next course of action is get the car up in the area and put a load on the suspension as it would be felt while driving and then see if there is any type of binding going on. Then also separate the ties rods and see if there is any binding in the strut tower area.

DriveFast7

iTrader: (1)

If the tie rods or idle arm were shot to hell it could do something like this. How much slop is in the steering wheel. How much must the steering wheel turn in order for the front tires to start to turn?

Front hubs tightened down properly?

ray green

iTrader: (14)

"To clarify this. The steering wheel does not have a issue returning to center but the tracking of the vehicle will not return to center if you make a right or left turn. It just keeps drifting to whatever direction you turned last. There is no "physical" pull felt in the steering wheel as you are driving."

"Replaced Idler arm bushings as they were cracked. "

I drove friend Mike's car after he put in a "performance" idler arm. Did the same thing you are describing, wouldn't go straight after you turned it. He had me test drive it, not a good thing, everything was stiff, not like the nice 25 year old FB suspension it should be. But after a few weeks it loosened itself up and was OK.

Bingo, maybe?

NCross

iTrader: (18)

Could it be a rear end problem? I'm not sure if the FBs had any sort of rear DTSS like FCs.

Buggy

iTrader: (8)

I would go with the theory of the idler arm bushings having to be worn in. What you are experiencing is "memory steer" which can be caused by caster being out of spec (which you have fixed) or some sort of steering component being too stiff. Make sure all of the front end componets are lubricated and can move freely. If at all possible, put the front wheels on turn tables and try and swing the steering by hand. It should move fairly freely and smoothly without a whole lot of effort. I would think though the alignment shop would catch this when they do the caster swing. This is a puzzler.....enough of a puzzler that I am going to dig out my notes from trade school and see if I can come up with a solution. I would really like to see a copy of the latest alignment printout. It might give me some clues to go from.

RXnos1200

iTrader: (24)

Well maybe the control valve isn't working properly. When that happens it bypasses the fluids to one side or the other and favors the direction you're turning. I know you said you disconnected the PS but the fluids will still push in the system.
Maybe you can try to bypass the CV and see how that works.
Looks like you have covered everything else.

rigdeng

The condition you are talking about sounds alot like Power steer pull or "self steer." Im not sure if your car has a integral or non integral power steering system. If you changed the pump and it is in fact a non-itegral system then there still could be a problem in the power piston. The spool valve in the directional control body may be misaligned or just worn out. jack up the front end, start the engine, and see if steering turns in either direction without imput you may have this condition, in which case replace the power piston.

As for all you alignment machine "nay-sayers," lasers, when properly used are 1000 times better than the naked eye. having said that, alignment machines are only as good as the person operating them and the imputs in the machine. ANY adjusment from factory spec comes into play with alignment. Tire size, rims, inflation pressures, weight distribution, lowering springs, etc. As most often is the case with tuners, SOMETHING has been changed from factory spec and at this point it becomes a guess and check game. Use your strings all you want, but you will never be exactly to spec, especially on a modified vehicle.