Is it Alignment Shop or Busted Suspension

[Radiation Joe]

At this point I'm leaning towards incompetent alignment shop. Looking for alternative explanations.
After having the rear sub-frame out to install Whiteline mounts and LCA bearings, I got the car back from my local shop with the rear suspension all bound up and making lots of noise. I didn't bring it back to the installers because this is strike two with them. Two strikes and you're out is my motto. Put it up on ramps in my driveway and clocked every bushing I could get to. Then brought it to a local tire store I've been working with for years for an alignment. Here is what they say I brought them and what I left with.

The technician was whining about not being able to get the car to take the alignment and took two full hours to get to the settings shown above.
With the exception of rear toe settings not too bad, but my steering wheel was at 30 degrees. So they took it back in and made some adjustments to get my wheel "close" to 0. I'm really starting to wonder about the alignment accuracy at this point.
I drive the car for a couple of weeks with two long drives that worked the suspension pretty well. By the end of the two weeks the car is driving well and all noises have stopped. I say pretty well because on relatively hard cornering over rough patches of pavement the rear end seems to be bump steering pretty significantly. Bump steering enough that I begin to think I need the Ford Performance Knuckle to toe link bearings.
I drove briskly from Ocean City, MD area to Allentown, PA area this morning, and when I got home I noticed the rear tires were hot and sticky while the fronts were normal. I believe the rears are showing significant wear across the whole tire in just the last two weeks. I call the tire shop that performed the alignment and tell them I need an alignment check. This is what they show me:

I haven't hit anything and don't believe I've done anything that could have caused this kind of a change. I believe at least the toe readings in the rear because they support the behavior I've been feeling out of the rear end.
This is what they tried to tell me was acceptable. I asked if he knew how to read an alignment sheet.

This is what I left with

It's too much toe-in in the rear for my tastes, but I just wanted to get out of there.

So after that long-winded diatribe, do I have an incompetent shop or something not right in the rear suspension? Note that they told me they could not get any more camber out of the right rear today, when previously I had -1.3 degrees.

I forgot to add that two days ago I added a Steeda 4pt G-trac brace to the front end. I doubt it's related to the issues but full disclosure... yada, yada, yada. (Unrelated, but Wow! did that improve the feel of the front end.)

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[NightmareMoon]

Yeah find a different shop. I think he didn’t know where the camber adjustment was located on the rear. Its not marked and just looks like a bolt.

since camber and toe cross-talk in the rear suspension, changes to toe will shift the camber some.

 

[Radiation Joe]

Thanks. I suspected all that toe was limiting the available camber. He knew where the camber adjustment was. He just didn't want to hassle with that adjustment again.
This tire store is also responsible for rear ending my wife's Explorer last year to the tune of $10k in damage.

 

[Dana Pants]

Camber and toe cross-talk so much in the rear suspension I made a plot in excel because I was driving myself insane.

 

[Radiation Joe]

Dude!
You have to post that. It will be sooooo helpful.

 

[Dana Pants]

Tada!

 

[Brian@BMVK]

^^^ Lovely consequence of the integral link design versus a more conventional multi-link.

Agreed with others, take it elsewhere.

 

[Radiation Joe]

Thanks @Dana Pants.
I found a shop about 45 mins away. Maybe I can make some points with them by sharing your plot when I go in.

 

[GT 550]

I drove briskly from Ocean City, MD area to Allentown, PA area this morning, and when I got home I noticed the rear tires were hot and sticky while the fronts were normal.

Try reducing frequency of power slide on corner exit? j/k

Seriously though if you've had the subframe out I'm wondering if it was poorly aligned when it was put back in, can't see your mods listed so not sure if you're running something like the Steeda locating dowels.

 

[Schwerin]

You're in Allentown? Call up R/T Tuning. They do lots of track setups and alignments

 

[Radiation Joe]

You're in Allentown? Call up R/T Tuning. They do lots of track setups and alignments

Thanks. You're spot on.
Called them three weeks ago, but couldn't get on the schedule right away. Now I'm going to them to fix what my local tire shop messed up.

 

[Schwerin]

Thanks. You're spot on.
Called them three weeks ago, but couldn't get on the schedule right away. Now I'm going to them to fix what my local tire shop messed up.

They did my friends Subaru and did a turbo upgrade on a buddies Q60. Both were very happy with the results and work. I keep meaning to call them but want to get my IRS braces on first. Let me know how it goes.

 

[Cobra Jet]

Two of the attached docs are from the factory shop manual regarding REAR S550 alignment and the third attached is the alignment specs in general across the platform.

The files are labeled "2016", but for the most part the "base" S550 chassis hasn't really changed drastically from inception (2015) to current day.

Do keep in mind if a user is viewing this or the attached docs and owns a Mach 1, GT350, GT350R OR a GT500, obviously the suspension and alignment info will be quite different from the "base" S550 suspensions. The PDFs may not apply in those instances.

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With that said, if it took your suspension guy or shop tech that many tries to getting the suspension tweaked to your liking, he's not well versed in alignment TECH other than "red" or "green". That is the problem with most auto shops is that they go by "red" or "green" indicators and call it a day, even with actual SPECS from an aftermarket camber plate setup OR stock from a shop manual. They do not know how to interpret actual degrees of alignment. They just go with "red" or "green", eyeball the steering wheel that looks straight and go on a test drive that "feels ok". As long as the car doesn't exhibit any issues on a 25mph drive around the block, they hand the keys back to the customer with the "red" and "green" telling the customer (who usually does not understand alignment either) that anything in the green is now good. They also will say if a red is remaining that they could only get it that close and can't do any better, but all should be well. True, well enough that your tires won't go bald immediately, but possibly will within 6 months of highway use.

Standard auto repair box shops - Midas, Meineke, Firestone, Good Year, PepBoys, BJ Wholesale, SAMs Club, Costco, WalMart Auto Centers, (enter your local corner shop here) aren't used to dealing with "performance" alignments outside their "script".

If a Performance Shop is near you, one that actually specializes in suspension and alignment (not the whole gambit of "everything car") OR Mustangs specifically, that's usually the shop you need/want. These guys normally deal with aftermarket suspension items, camber plate setups, lowering springs, IRS upgrades, customer requested alignment specs, track alignments, etc.


Hope the attached helps.

 

[Radiation Joe]

@Cobra Jet,
Thanks, and you are spot on with my local tire store experience.

 

[Radiation Joe]

Finally got the alignment done. My tension links didn't show up in time from one of our well known vendors, so I'll be back in the alignment shop in 3 or 4 weeks to install those and align the front again. It might be a blessing in disguise because I've been wondering if something is amiss in the rear suspension.
Every time I've aligned it (four times in two months) the rear has started out different from the last time I had it aligned. Once is due to the new toe link bearings, but the others are either incompetent shop or something wrong in the rear end. So next time it goes on the rack I'll find out if I've been chasing a rear suspension problem.
A shout out to Pat at RTTuning in Montgomeryville PA for giving me an alignment exactly matching my request and providing a car that handles more in line with the way I would expect it to. @Schwerin, you were right about RTTuning. Great bunch of folks. Dyno run after dyno run going on while I waited. Very knowledgeable.

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