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I'm befuddled and dismayed by recent developments with my 2016 Cayman GT4. In August 2019 the transmission was replaced under the infamous 981 GT4 transmission recall. It hadn't failed (yet), but during routine preventive maintenance I was informed Porsche would replace my transmission. When the job was done and I received the car back, I noted the alignment report showed right front caster slightly out of spec. (See first image.) I took the car back some days later and they assured me it would not affect the ride or safety but if I scheduled shop time at my convenance, they'd "take care of it." Given that it was late fall by then, I was offered the option of bringing it in the following spring. Fast forward to May 2020. I brought the car to the Porsche dealership for an oil change and to have the alignment re-done as per our prior conversation. Upon check-in, they informed me that at 4 years old regardless of mileage, my GT4 was due for new plugs, brake fluid flush and a few other items. I said "do it." Lo and behold, I get a call a few hours later saying, "We need to talk about some of the alignment values we're seeing on this car." (See second image.) I went in and was aghast to see that the car was out of spec in three of four corners. No sentinel event whatsoever while driving last fall or this spring. Car sat in the garage under a cover all winter. "Had I crashed?" No. "Had I hit a pothole or other road debris?" No. "Has anyone other than this dealership worked on the car?" No. "Etc., etc." We inspected the undercarriage - no trauma or drama, scrapes, bent suspension parts, wheels or underbody cladding. Even the fragile rear brake cooling air intake scoops are intact. They have had the car four days now. Maxed out adjustments one way then the other. Cannot get a proper alignment. Called Porsche of America. "Try loosening the rear subframe and moving it." No solution. (See third image w/bulletin.) So today I'm missing a 250 mile (COVID-19 safe) PCA drive on a beautiful sunny Saturday while my GT4 sits on a rack in a dark garage. Anyone seen anything like this? Any ideas? Could it be related to the transmission replacement? Alignment immediately after transmission install and before alignment, then after alignment. (August 2019) Alignment upon installing on rack. (May 2020) Action suggestions to technician by Porsche (failed).
You’re over reacting 🙄. These numbers aren’t even that out of whack, all cars go out of alignment over time if you drive them. Yes the transmission replacement does require a new alignment since the rear suspension is taken apart. Yes moving a subframe is perfectly fine because it’s a part that attaches to the frame, just like the suspension is attached to the subframe. They all have tolerances and move around, just get it adjusted.
After my first track day my alignment got tweaked so I took it to a Porsche specialist between home and the track to get it looked at. Well known reputable indy with all sorts of crazy cars in the shop including a 959 and a Ruf. My car literally had just a few thousand miles on it and they totally effed up my alignment. Told me they couldn't get it to Porsche specs, put huge spacers on one side but not the other, even suggested that maybe the subframe was out of spec because "that happens". I literally watched those monkeys mess with the car on the rack for hours. A few hundred bucks and many hours later I left with the car still pulling left.
Drove it home, freaking out the whole way wondering if I had bent something in my new car first day out at the track. I took the car back to Deman, apologized for letting anyone else touch my GT4, and they pulled the spacers and got everything back to perfect, NBD.
I would take the car to a different shop and make sure they are putting the right weight in the driver's seat before freaking out that there's anything wrong with the car.
Don't know why plugs need to be replaced regardless of mileage. Plugs are not a time-dependent maintenance, so this raises my eyebrow on the ethics at this shop right off the bat.
Short answer, yes, the transmission swap may have led to what you are seeing. It can be corrected by a competent shop. Also, wheel alignment machines are not always consistent, mainly due to how the tech mounts the wheel attachments on each wheel (for a Hunter laser type, etc.). This is one reason string alignments are often used for track or race alignments. I had my car on a rack trying to get -2.5 camber on rear after adding Tarrett toe links. Shop said it wasn't possible, using a Hunter machine. Came back after a track event and voila, no problem getting -2.5 on rear, same machine, same tech. and the car had no impacts or events out of the norm between visits to the alignment rack. And due to the frequency of track alignments I've done for about 2 years, having done at least 6, IIRC, I know my alignment doesn't shift much "by itself" from event to event, alignment to alignment.
I had a well known shop that has won cup car races fail to get max rear camber out of my GT4 when he local Porsche dealer had no issues doing the same. On another visit I had paid them to mount new tires and do a track prep inspection and my tires were 15 psi over pressure when I left. Even good shops have B and C teams.
Thank you to those who responded to my (first ever) post. I appreciate hearing from you. I thought I would report the results. The invoice and technician's report reads as follows:
"Customer says perform 4 wheel alignment. Caster is out on right front after transmission job. (see first image from August 2019, above). Could not align. Performed adjustment as per technical information 38/16. Created VAL. Followed TI 38/16 and adjusted left side carrier. Alignment would not come in. As per TI 38/16 lossened complete side carrier and adjusted upper mounts. Alignment now possible. Vehicle operating as designed."
They had to order three new (single use) bolts to re-fasten the carrier and upper mounts. All work was done under warranty (which was extended 90 days due to COVID-19).
The new alignment sheet is attached. Note that now, both side caster is slightly out of spec, but after what it looked like in the second image above from May 2020, I'm gonna remain silent at this point.
Glad to be driving my GT4 again! They completed the 4-year service too, so I'm "good to go" for a while.
Castor shown is a non-issue because it is balanced left/right. No worries. If those final numbers for all settings are accurately shown, it will drive perfect. If you track it, you will definitely want more front/rear negative camber.
A few years ago, I did experiment with repeat measurement in alignment shop with Hunter machine.
Setup, Measured, Record the numbers. Take off the alignment tools, repeat.
The camber , caster remains relatively close, within +/- 0.2 degree of prior measurement, no big deal for 0.2 out of 3.5 degree camber or 7 degree caster
The toes , however, would change like over +/- 0.05 degree (this is huge since the toe tolerance is about +/- 0.05 degree per wheel.
So, I agree with others , not to worry about the toes changes as long as it drives normal.
My understanding :
60 ' (minutes) = 1 degree
Factory spec is 10' -/+ 2' = 0.13 degree to 0.20 degree
The OP print shows toe in degree.minute ?
So in his print out the range was 0 degree 8 minute to 0 degree 12 minutes.
I suppose some alignment machine reports toe in "inches" as you translated ?
The shop I went to, reports alignment in degree decimal points.
So I translated the range 0 degree 8 minute to 0 degree 12 minutes to 0.13 to 0.0.20 degree per wheel.
05-16-2020, 05:18 PM
GT4 Alignment Fail
