Landseer

Great outcome, had to "sell" my way into the bay, though. Sat morning, busy time, was there early, still, bad day to screw with Sears....Was talking to Rog, he said i should post because he knows of 928 guys turned away at Sears.

Conversation went something like this:

Sears girl: "which car is it"
me: "red one"
Sears girl: " we don't do them"
me: "I think you have all the computer programs"
Sears girl (over intercome): "joe, can you come up here?"
...
Joe: "what year is it?"
me: "84. but my guys on the net say this is the absolute best place to come, that sears has hunter, hunter 400, and the programs are loaded.
Joe: "but I don't have the tools"
me: "you don't have metric??"
Pause
Joe: "yeah, i got metric... come back here"

We walk to back, he punches in the 84 928, pictures come up.....
Program shows adjust points.... THEN.... shows that first step is adjust ride height, remove wheels.....pictures....SHOWS the device to winch the frame downwards to restore spring configurations.....

me: "you don't need that. Ride height is ok now. Joe, just get me close. C'mon man, I got one wheel going straight, one going right, I need help and you got the tools. I don't want the warranty, I just need you to get me close!!"
There's no way you can go wrong. I accept any problems, even stripped bolts, just see what you can do! All the parts are new. You can't go wrong"

(I replaced shocks, inners, outers, uppers, lowers, wheel bearings, upper a-arm bushings....)

Joe: "OK. I'll give it a shot"

Voila:



So, gotta get the tech to SKIP ride height portion of program, move straight to alignment.
Pretty simple. Worth every bit of 69.95 USD. Car tracks nicely. I'll go back and tweak ride height when the time is right, then it might get closer...

Bill Ball

Joe did OK, especially on toe.

It would be better if the caster were closer side-to-side (less cross-caster). The car might pull to one side.

Odd that he couldn't get the rear cambers the same, as well. Usually the rear camber is too negative due to old bushings or low ride height, but your right side is much less negative.

Which way are you going to tweak ride height? Raising it will make toe and camber more positive. You have toe right where you want it.

Angel84-928

Your FR Caster, Front Cross Caster and both rear Cambers are still slightly off after the alignment. They are much better than what you started out with but is this a typical result?
I'm not criticizing, just wondering what to expect because I'll have to get this done soon.

Being a Quality Assurance guy by profession, I'm alway look for optimum setting from an adjustment range.

Thanks for the post Chris.

Landseer

Umm. I currently have no idea how to approach it. Figured I'd find the answer in the 25-odd pages of yours' (Bill's)and Earl G's and Dr. Bob's printouts, though....

Marine Blue

Sears gave me the thumbs up when I asked but I was lucky enough to find a small local shop that specializes in Porsches and specifically 928's.

Did they charge you extra? My conversation went like this:

Me: How much for a four wheel alignment?
Sears: We charge 79.95 for an alignment, what kind of car?
Me: It's a Porsche 928
Sears: Oh we charge 99.95 for sports cars
Me: Ok
Sears: We'll probably need some extra time to get it right
Me: No problem

I left at that but if I hadn't found a good altnernative I was prepared to babysit them as needed.

Bill Ball

Even though Angel and I noted the specs that are out of range, if the car does not pull on level ground, don't worry about the cross-caster. Your toe in the front is as close as anyone can get it to dead center of the spec and the rear is good. Some of the other numbers are just a bit odd. I would want them all in range and close side-to-side, but at least you have the toe dead-on, as it should be.

What is your ride height and what are you planning on doing to it? Obviously it would have been better to get that where you want it before doing the alignment.

mark kibort

so, let me ask a simple question. in finally setting my own alignment, rather than my crude checks periodically, how does a car pull to one side? i kind of understand if caster was off , but is it more of an issue of the setting of the rear toe ? (not total rear toe). toe in, up front wont make you pull but going straight might make your steering wheel off center a bit.

thats leads me to the other question, how can you have one front wheel with more toe than the other? It must be referenced to the steering rack center position. if so, doesn't the one wheel that is toe'ed in more, have some funky effect on the caster and camber? So then, if you ignored the center alignment point, and turned the steering wheel to "share " the toe in, the total toe would be X. you would take some toe out of both wheels , and the caster and camber of both might be at different starting points as well. do I have this right? There probably little to be gained by having the rack perfectly centered. What, do you loose a little bit of turning radius on one side?

Let me know if I am thinking about this in the right way.

Thanks,

Mk

Bill Ball

Although the front wheels are naturally self-centering, if you have unequal front toe, you will get more bump steer and wandering from unequal tie rod lengths going through different arcs causing different toe changes under load and when turning. That's why you should use a centering bolt during the alignment. In theory you can rely on a centered steering wheel, but this was not true in my car because the universal joint between the steering shaft and the rack was mounted 1 tooth off, I believe at the factory (I have complete service records and no work was ever done that would have involved detaching the steering rack from the universal).

Yes, unequal caster and/or unequal rear toe cause car to pull to one side. Actually uneven camber can do it too.

Camber and caster adjustment definitely affect toe. As camber is made more negative (by moving the bottom of the hub out), toe becomes more positive as the rearward steering knuckle is held where it is by the tie rod and doesn't move out. Caster effects toe by moving the bottom of the hub fore or aft, changing the horizontal angle of the tie rod end relative to the rack. The affect of toe changes on caster and camber appear to be more subtle because the toe angle changes are so slight, but obviously as you turn the wheel the camber changes are large.

Landseer

Thank you for the thoughtful comments and all additional questions so far, the dialog is helping me understand the alignment variables and perhaps how to tee-up the next steps of cleaning-up this needy old shark we have here.

I'm just trying to get onto the road with it and hopefully will iterate to a tighter alignment later as other repairs and improvements are made. One point of making this post was to point-out that anybody wanting to take advantage of a Sears alignment for $69 (which could be the only Hunter 400 in their easy reach) would need to know what the technician was reading on the set-up program.... hence prep oneself for how to sell their way onto the machine or otherwise deal with the tech.

The car is tracking quite straight so far on presumeably flat highway, wheel centred, though the whole car and 928 driving is essentially new to me. (Am switching between it and a K-pickup w/ 300k mi, an ever-so-slight difference in road feel.)

What wear-parts should I consider at the rear of the vehicle? Have not yet touched this area, other than brakes. I noticed a bit of a bend to the L. rear link, btw, so could that be important? Forgive me, as I haven't done too much searching on this rear topic yet.

When I changed shocks, I simply counted and matched threads. No basis existed for me to believe that it was right, but it was the main starting basis I had at that point. Plus, it was on jackstands for 3 months straight afterward. I was rough-comparing with a stick the distance from garage floor to fender lip a few weeks ago, after it was on ground, and different times thereafter. Amazing how far it dropped and how long it took to drop. Seemed very close at the time of the alignment. What should be my measure points?

OK, off to get inspected and make the first run to work, 35 mi. wish me luck.

Thanks

Rob Edwards

For measuring ride height, check out my pics in post #44 of this thread:

https://rennlist.com/forums/showthre...+height&page=2

mark kibort

Thanks Bill. So, Toe is self centering, so it wouldnt be the reason for a pulling situation.

I still have a hard time believing that the small difference in tie rod lenght to even adjust this car's specs (as shown by the sears sheet) would have any effect on bump steer. would it??? looks like he was 1.5 degrees toed out on one side and near neutral on the other. wouldnt that mess up all the specs on one side, but if the wheels were centered (not the steering wheel) wouldnt the difference be split between the two wheels and the problem be much less, especially if you just adjusted the toe for both equally? we are talking maybe a few threads on the tie rod. So, would it really matter?

of course this if for the short cut, budget racer guys like me without the $70 to spend on the aligment rack.

I just measured my set up after doing the level and magic marker technique. (has been verified on the hunter machine 6 years ago) with the new tie rod, and .5 thread toe in change with the new part, the alignment is 1/16" toe'ed in vs the before setting of 1/16" toe'ed out. 1/8" total toe change. the wheel setting did change to reflect this and ill have to move it one spline on the steering wheel to center the wheel. I think it turned out just as i wanted
Ill see if 1/8" toe in vs toe out that much, saves the tires' inside tread area.

thoughs? (sorry for the hi-jack)

MK

Jadz928

Chris,
Good write up. Sounds like I may give Sears a go. What Sears did you go to?

Oh, and let us know how the ride goes....

Bill Ball

A while back I wasted $200 on an alignment that came out a lot worse than yours. I wasn't paying very close attention at the time and only noticed how far things were left off the mark later. And the car pulled to the right, although I didn't notice it at first.

If you are talking about the flat brace that run across the rear lower control arm, that is often bent by improper use of tow truck loading hooks. There was a thread on this a few months ago dealing with BrendanC's suspension. I don't know if you should try to straighten it or not. The rear suspension has a lot of rubber bushings that can deteriorate, but unless you have good evidence they are gone - clunk, clunk or inability to align - leave them alone. Your low camber on one side is odd - the upper control arm bushing compresses with age and RAISES negative camber, not lowers it. I'm not sure what your low camber on one side means. It may mean nothing. It may mean the adjuster is assembled incorrectly (I don't think so, although I have seen this in the front). I just haven't encountered it. Maybe someone like Earl Gilstrom will pipe in.

What you did when you installed the new shocks is how I approach it, then measure actual ride height, as Rob shows. There is a fair amount of anecdotal experience that same spring length (i.e., same adjuster settings based on measuring the exposed threads) provides good corner balance rather than getting ride height exactly the same on side-to-side. I set the adjusters the same on both sides then measure ride height. The WSM allows a difference of 10mm side-to-side. Mine are usually within 5mm. You know the front needs a lot (70-100 miles - shorter if real bumpy) of driving to settle. The rear requires only a little.

M. Requin

Jim , if your experience is ok and you use the same tech, I'll drive over to Richmond, too for alignment (if Chris shares which Sears ). Maybe we can give the guy some experience with 928's and a local rep. Could be useful!

dr bob

Mark--

I'll pile on here. What's a good alignmnet thread without a lot of opinions...

IF (and this is a pretty big IF...) your garage floor is level side to side, you can do the camber and toe adjustments pretty easily at home. The level-against-the-tire method for camber is crude and generally inaccurate, mostly because the tire bulges at the bottom against the floor. Borrow or make a couple metal brackets that you can tie to the wheels (not the tires...) so you have a good platform from which to measure. Then do your trig based on target camber, the spacing between the measuring points where you rest your level. Solve for the distance between the top crossbar and your level, the space needed to get your spirit level to be vertical. I used the Captain Earl drill-bit spacer option when it came to getting it just right. With the car sitting on a level side-to-side floor, you can adjust camber so it's exactly the same on both sides. Do the rear too.

Then go on to toe. Poorly adjusted toe will wear the tires funny. Unevenly (off-center) toe will cause the steering wheel to be off center when driving straight down the road. You mentioned that you replaced one tie-rod end, used the thread-counting method, and came up with a steering wheel that isn't centered. And the total toe changed. Rather than just popping the wheel off and moving it a tooth, why don't you adjust the --other-- tie rod so the toe is correct and the wheel is centered? WYAIT, replace that other tie-rod and end too. Can't understand why these would ever be replaced individually unless one was bitten off or something.

Follow Earl's guidance on getting the rack centered, -then- then toe the front wheels so they are also centered on the centerline of the car. This is Very Important. Follow Earl's guidance on this! My little laser fixtures make it a little easier than using his strings method, but his method works and it's not tough.

Once you get the settings where you want them, use a paint marker to show where everything lines up. I can tell you that 1/16 of a turn on the tie rods makes the difference between being in the acceptable toe window or out, so mark carefully. Then when you get to the track and decide that your car really likes just a little toe-out with the more positive offset front wheels, you can restore the original street toe setting for the ride home. Like every other adjustment you make to the car, document your changes to the car and the results you experience. Reference your paint marks in your adjustment log, and use your digicam to assist your memory as needed. Once you have good reference settings, you can do freehand toe adjusts at the track for testing.

Have fun!