jeff spahn

I had the alignment done some time ago and gave some specs a few people had recommeneded. It seems these settings had made the car very twitchy and nervous.

Can I get some recommendations for alignment settings to make the car more stable and less twitchy. It seems to tramline even worse now that the front end was made more responsive.

Some feelings I get with the current alignment settings (all in factory spec) are:

Feels like it keeps turning after I have entered a turn (have to counter the wheel a little when in a sweeper).

Rear end rotates around very easily once the suspension loads up.

Steering is very, very light.

Tramlines over the tiniest pavement imperfection. It really isn't even fun to drive right now. I have to steer against the curve many times to keep from running off the road.

Rack is 6 years old. Tie rod ends are 6 years old. Shocks and springs are new.

I am considering putting new ball joints in to see if this helps anyway. I know lower can be replaced but I have to look at WSM yet to see how the uppers are done.

Also any suggestions on bushings I should think of replacing when I do the ball joints this winter would be appreciated as well.

Marine Blue

I would be interested in knowing how the steering was lightened.

For reference when I had an alignment done on the S4 I noticed that the car was extremely stable at low and high speeds with no tramlining or twitchiness. The shop that did the work put everything within factory specs.

GregBBRD

Jeff:

You need to take it by another alignment shop and have them do a check on the numbers.

The super light steering and the fact that you have to counter the steering wheel to return it to center means that the caster is way, way too positive.

That simply can't happen, if the car is with-in factory specifications.

Mrmerlin

you need to inspect he tie rod ends inner and outer
next set the car to correct ride height about 160 MM all the way around. Next check the BJs.
Inspect the rear lower control arm bolts to the crossmember,
these bolts are torqued to 140 ft/lb if they are loose then the rear end will move sideways this will make the car feel very loose. look for wear marks next to the eccentrics,
movement will leave polished marks, check for tightness also inspect the rear lower control arm to chassis bolts these ae 82 ft/lb

jeff spahn

Cool, thanks everyone I'll get on this right away and report what I find

jeff spahn

I might not have stated how it feels correctly. The car will center itself if you let go of the wheel. To more accurately describe what I mean is:

You are in a curve on the highway. There are "ruts" in the pavement from all of the semi trucks. As you are taking the 65 mph curve you may have to from time to time steer towards the outside of the curve to keep from diving to the inside.

Perhaps that is a better way to put it. The car is like the princess and the pea. It finds and follows every tiny little distortion in the pavement.


The tires are Michelin Pilot Sport A/S Plus on the front at 36 psi. Rears are Fuzion ZRi at 36 psi. Fuzion's are new because the Michelin's lasted all of 11,000 miles before they went to the wear bars. Wore evenly all the way across.

Ride height is set to factory specs. I have pieces of wire cut to the WSM specified heights that I measure from time to time at the data points on the suspension (those little cast in dots). They are within 2-3 mm every time.

I have the Eibach springs that were on sale last year and new Boge or whatever the standard replacement shock is that Roger sold to me. Not a Koni or anything fancy like that.

Upper BJ boots are torn (Greg pointed this out on the PPI). Lower BJ boots are fine. Outer tie rod ends are 6 years old. Inner, no idea. no play when I grab the tie rods and try to move them. Greg adjusted the wheel bearings at 98,000 miles. I have 117,500 miles today. That was 11 months ago.

I assume the rack bushings are good because the rack is 6 years old also. Boots are perfect on it.

Is it time to replace the upper ball joints and lower? Just due to age? I have all receipts from work on the car since new and see no notes on ball joints, upper or lower being replaced.

The tramlining makes the car less than fun to drive and gets more annoying, though no more severe, every day.

Mrmerlin

to check the tierods with the car on the ground and the engine running have a helper turn the steering wheel back and forth about 1 to 2 inches slowly while you look at the tie rods from behind the front wheels,
block the wheels so the car cant roll.
If there is play in the rods you will see it,

note you may have to pry the inner boots off the rack to view the inner tie connection,
also look at the rack bushings see if the rack housing is moving back and forth

Landseer

Did they align the back?
How is back suspension?


Why did you need specs?

The modern alignment machines, like Hunter 400, already have the specs loaded.


My major source of play was the universal joint on the steering column.

AO

Do you have the alignment report from the shop? Posting the results would be helpful.

Any chance the car wasn't fully settled when the alignment was done? Any chance they lifted it?

I'm with Greg on the caster settings. Sould like maybe they're not quite where they should be.

Unfortunately, for all 928 owners, driving in ruts, is an unpleasant experience. I think this is partially due to the Weissach axle - which imparts a passive steering effect.

Landseer

My alignment guy had to deal with an unexpected sign-change within the 928 program on the Hunter machine with respect to caster readings. Not sure what he meant, but it had to do with caster adjustment being below instead of above the axis on these cars vs normal stuff he works on.

jeff spahn

Thanks Landseer. I'll take that to him. That could be just what happened. They don't lift the car, I watched them do the alignment. Suspension was fully settled. I set the ride height before the alignment and then drove about 30-40 miles over the nastiest bumpy roads I could find at city speeds. Up down up down. felt like a rodeo horse. Car was visibly lower when I got home and I was shorter. My martini was nicely James Bondified though.

RKD in OKC

I had a weird twitchy alignment, turned out the caster was off.

bigmac

I had my alignment done at the local Porsche dealer who did a wonderful job, using the alignment device in the Honda shop, once they knew that it was a 928.

jeff spahn

So here's what I found on the tie rod ends. There appears to be no play in the rack with the bushings or visible in the tie rod ends. I put my hands on the tie rods as my wife rocked the steering back and forth. I could just barely feel a minute amount of play. Almost a "tic" movement as the steering went back and forth. Same feeling on both sides. Probably not any more than a gear mesh amount of movement from the feel of it.

Is this what I should be feeling? If not, I'll have the shop replace both inner and outer ends.

Then after I get feedback, I'll go in and get the caster put more negative.

Mrmerlin

slide the inner boots off the the rack and watch the inner tie rod for movement,
any play then they need to be replaced