jeff spahn

What I did at the alignment shop: We lifted the car by the control arm points and kept the suspension weighted. We swapped tires from side to side (they are directional). I took the car for a drive and it appears I have a tire issue.
The car now pulls right. Seems that the alignment brought the car back into spec but the tires were worn and pulled left. Ordered two new Ventus V12 Evos for the front. This should do it. We will see.

the flyin' scotsman

interesting Jeff.

What type and size of tyre? age?

jeff spahn

Tires are Hankook Ventus V12 Evo. 225, 35 ZR19. They have about 8000 miles on them from me. Had them for about a year. Got them from a RLister on a set of wheels. He had used them for track use for a few thousand miles at most.

Funny thing is they never pulled before I took the front end down to do the OPG/Bushings. Now that I put it together and got it aligned it pulled. Switched the wheels and pulls the other way.

Must have been worn funny. I'll get the new ones in a week and post what they work like. Pretty good price at 198 each.

the flyin' scotsman

that is a great price

FredR

Just goes to show you cannot take anything for granted

Regards

Fred

WallyP

Years ago a friend installed new tires and got an alignment (all at Sears), and the car then pulled to one side. Sears redid the alignment, which didn't help. After several visits to Sears, and much very spirited discussion, he just happened to notice one day that Sears had installed two different sizes on the front...

DKWalser

Any update?

hacker-pschorr

I've seen before where before you replace something in the suspension, the car was aligned but the "worn parts" allowed the tires to wear in funny.

Now with new parts and a new alignment, the "bad tire" is causing the pull since it's spent the last X miles having a goofy wear pattern worn in. There is a term for this but I cannot remember / find it.

My fathers Yukon has one summer tire that will cause a pull if on the front. No issues if mounted on the rear. That tire shows zero visual issues and has been dis-mounted and balanced.


+1

This is why in order to do a proper alignment you must raise the car. You cannot properly inspect suspension parts when they are under load.

I would never have my car aligned by a shop that doesn't lift the car off the ground (wheels dangling) and inspect all the parts.
I suppose most people go to shop A for suspension work and then shop B for the alignment. Still, an experienced alignment tech would want to do their own inspection since it's their butt on the line if the alignment doesn't come out. I do not know any mechanic that would take the owners word for it that everything is tight and not worn out.

The WSM specifically shows how to raise the car, and pull it back down for an alignment. Follow the factory procedure!!!!

DKWalser

I am so confused! Everything I've been reading about doing an alignment on the 928 says it cannot be done until the suspension has had a chance to settle -- which requires driving the care about 100 miles. Now, Hacker (whose opinion I respect) comes along and says that common wisdom is wrong? Which is it?

I thought the proper procedure was to do the alignment (keeping weight on the suspension) and then do a complete inspection with the wheels dangling. Of course, that risks finding something that needs replacing/adjusting and having to redo the alignment after those repairs are done (and after the suspension has had time to settle). Or, inspect and repair and do the alignment a week later.

What's the proper procedure? I just had my shocks and tie rods replaced. My mechanic set the to-in and told me to have the alignment done after 100 miles. I'm in the process of deciding where to have the alignment done. Do I tell the tech to keep the weight on the suspension or not?

hacker-pschorr

The proper procedure is in the WSM.

It's well known the 928 front end doesn't settle on it's own for a X miles, and if you align the car before it has been settled, it will be off.
This is a fact.
The key phrase here is "on it's own" - you can settle the suspension manually once it's on the alignment machine (which is the preferred way in the WSM).

Over the years it has become "internet fact" that in order to do a "proper" alignment you must find a shop that will not lift the wheels off the ground.

Technically this will work, and it is better than lifting the wheels off the ground and doing the alignment at the relaxed suspension setting.

Reality is, this is not the preferred way, and not how Porsche describes how to do an alignment in the WSM.

Have you ever done an alignment? It's amazing how sensitive that equipment is. The next time your car is on the rack, walk over and just place your hand on the fender. You will see the numbers change. Now image if you have a loose ball joint, tie rod end, control arm bushing etc.... Any issues with those parts can and usually will effect the alignment. Will it be enough of a difference for most people to notice? That's debatable, many alignments shops have a motto: "Set the toe and let it go" because that is the #1 measurement that effects tire wear. That is why it's important to get a print out to make sure they checked everything.
I know of a Porsche / Mercedes / BMW dealership who follows the "Set the toe" motto.... it's sad.

Why is this important? The first step of doing an alignment is inspecting everything in the suspension. If the tech finds something loose, fix it before doing the alignment. You cannot properly inspect most suspension parts with the weight of the car on the suspension.

After the inspection and all the parts are within spec, the car should be placed on the alignment machine, and pulled down to proper ride height. Porsche even has a factory tool for doing this. My local shop made their own, works the same. My shop has been servicing 928's (including alignments) since 1984 when the first 928 came into his shop. He lifts every one for an alignment, including his own 928's (he's owned a few...).

For those who do not have access to a shop that can do the inspection / suspension work and the alignment, this is where compromises come in, and frankly you have to work with what you've got available. So I'm not saying it's "wrong" to find a shop that will not lift the tires off the ground, I feel it's important people know the preferred method when shopping for an alignment.

Many will say: "I updated the suspension, there isn't a need for an inspection..." That's fine, but if I were the alignment tech I would want to check it myself. If the customer comes back with a bald front tire.....it's my *** on the line. An experienced mechanic doesn't take anyone's word for anything, especially the customer.

Again, I fully understand a lot of people are very limited on choices when it comes to finding a shop to do an alignment on s 928. I just feel you should know why you are looking for a "no tire lift" shop, not just doing it because everyone said you should.

OK - dug out the WSM and my scanner.... here you go:



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DKWalser

Very interesting. In another thread, several Rennlisters said they took their 928s to Sears to do the alignment. I doubt Sears or many independents would have the knowledge or the tools to follow the WSM procedure.