Afternoon,

I purchased a CPO '16 F-Type S in July with 26K on her. Tires were stock Pirelli's with an unknown number of miles on them, but plenty of beef, over 80% as the CPO inspection requires. Drover her from DFW Jag to Denver and drove her around the Denver area for a couple months, amassing a little over 2K miles on her. No hard driving, spinning/smoking rubber, drifting, track days, etc., just an occasional drive to work and around o the weekends. So the story begins.... at that point was down cleaning her tail pipes as part of a detail (amazing they get as dirty as they do from water and carbon, etc.) and noticed a rediculous amount of wear on the inside block (and ONLY the inside block) on the rear-left tire (Only the LR, all others are wearing normally), and Belt starting to show!! She had not been curbed, potholes, nothing I knew of to kill her alignment. She was coming due on a service interval at 30K anyway, so took her to a new Jag Dealer on the N side of town. The purchasing Dealer that I called (and talked to a manager) on it simply said, "It's a high performance car, it'll do that...." BS. Period.

So I take her in. They say there wasn't any problem with components being bent and they charge me for a 4-wheel alignment, but find nothing out of whack on that wheel, really, only a minor adjustment (.2deg toe), but adust the right rear toe as it was out into the red on the report.... though the wear on that tire was minimal and even across the tire. The offending tire did have two patches on it from a flat at some point.

So, 4 new tires later (purchased from TR), mounted and balanced by tbe dealer and about $1300 lighter in the pocket. I'm still a tad worried. The car never had tracking problems except on grooved concrete, though the tire noise that I now know to assiociate with her draging an edge (I just thought it was a Pirelli thing as I'd never had them before, nor this car) is now gone and she's quiet as the grave.... minus the Glorious Kat Growl, spitting, barking, cracking and pur.

Anyone else seen anything similar? Does the active suspension change camber (and the service techs swear there is no manual camber adjustment, only toe)? What else could be doing this? Why isn't Alignment checked in the CPO process? Thanks, sorry for the Novella, but perplexed.

-Scott

 

There is no rear camber adjustment on the F-Type and this has been confirmed many times.
On all my Jags (2010 XFS, 2010 XFR and 2014 F-Type S) the inside edges of the rear tyres have worn quicker than the outside edges.
Around twice as quick on the stock suspension and on the XFS on lowered suspension about 10 times faster due entirely to the increased negative camber which could not be adjusted out.
Not so on the F-Type though, despite VAP lowering springs the rear inner edges are wearing just a little bit faster than the rear outer edges, maybe 1.2 times as fast.
I have no idea why the inner edge on only the LHR showed excessive wear on your car, only that the adjustable suspension could not have been the cause.

 

Yes it has. While excessive camber looks like it's going to kill one edge in a hurry, toe problems are far more destructive. With toe set in correctly, the tire is essentially "cornering" all the time with a built-in slip angle. Put another way, a tire that is toed incorrectly will always be getting scrubbed down.

 

 

Thanks, was this on just one tire or both rears, all tires with yours??

It just seems awefully odd. If we're scrubbing $500 in tires for rears in 2000+ miles instead of 20,000+ miles, that's not good and is going to make my choice of the F-type questionable.

My girlfriend got a '16 XF and runs around in her in Dynamic all the time and all her tires are wearing flat and even after 12,000 miles since May, so clearly Jag can get a suspension to behave. Different tires, I get she's not a 'sportscar', but this is a design thing if only the F-Types are having the problems.

-S

 

While what you showed in the pictures is not normal wear, using up tires in a hurry comes with a territory. I am on my 4th set of tires now with some track use.

 

4th set after how many miles? Which tires and are the Pirelli's more susceptable than others seemingly? I put Conti DWS on her for the winter as we are in Denver. Don't want to get caught out in snow intentionally, but if it happens I'd rather her be ready. Had plenty of winter RWD experience with my s/c MR2 and GT86, but it's not fun with fools on the road.

Thx,

-S

 

That is exactly how the rear tires were worn on my '14 when I bought it. (16,000 miles on them)


I only changed the rear tires (the fronts were acceptably evenly worn). Again, I'm sure it is the alignment specs (that are optimized for handling).

 

If nothing iss bent and the car aligns, personally looking at the wear pattern the tire is telling me it doesnt like the toe setting in the rear. I would toe in the rear more, and i almost always toe to the inner spec and not in the middle like many seem to want to do. Why? Because the forces of driving down the road push out on the tires making them toe out more when driving. On the machine theyre in the middle, when driving they move out to the red. If i toe in more on the machine then when driving theyre then in the middle and wear better. You drive on a road not a lignmet machine and you have to know how that affects what the car does.

 

^^^ This is why folks that fit poly suspension bushes into their suspensions often have issues. With less 'give', the poly-equipped suspension needs to be set up differently than factory.

Plebeian alignment shops don't take that stuff into account, but race shops do. (Especially, if they know you are 'aware' of the effects.)

 

[quote=carbuff2;1995068
plebeian alignment shops don't take that stuff into account, but race shops do. (especially, if they know you are 'aware' of the effects.)[/quote]
or are a jaguar tech that has a 8 second drag car, custom offroad truck, custom lowered suburban with a 383 stroker lowered 8" with big brakes, huge front and rear sway bars and complete poly bushings in everything from body mounts to every piece of suspension. And that can stick with cars in corners if the other driver can drive. A have built them all from engines to chassis, trans and diffs. I do deviate from stock spec depending on what i want to do and the application. Everything i have has custom suspension setups. Well except my daily driven jaguar. But even that has 20" takobas from a xfr and use the same size tyres from a ftype r. And i have pushed that into 45mph curves by the house at better than 90 and 125 when apexed the corners and the road was shut down. Its all a blast. And yeah i like teslas too

 

^^^ Once again, we can't generalize can we? I sure hope I didn't offend you.

Some cars (that are lighter than the Jag) specify that the suspension be weighted to simulate the 'cargo', prior to adjustment. LOL. I KNOW that most tire-store shops don't do that type of thing unless they are asked. "Get 'em in & out, QUICKLY"

 

lmao no you didnt offend me. About the only thing that offends me is when people expect a "expert" to memorize everything abiout everything on all jags, all models and years and be perfect never making a mistake. Thats about it. I defend and blast dealers if needed. I do try to change the perception of dealers and techs at dealers in general i dont know it all nor do i want to. But i can usually find it knowing where to look.
I have a life sometimes outside of work

 

I'm new to Jags in Particular and 'High Performance/Luxury' cars kinda in General: the closest I had previously was a Lexus '06 IS350 that I loved everything on except the auto tranny... A big step up from the MR2 and 125cc Shifter Karts, but tangential to my GFs other Baby Girl, an '05 Lotus Elise. I really hate a computer telling me how to drive and when to shift... so this is all great info, including conjecture, to be sure and I appreciate it all! I just found a d/l of the Shop Manual for a '15 and will be investigating that some this weekend. Gracias Y'all, you've lived in this 'Realm' (Pun intended) much longer than I.

-S

 

 

Did you mean that both cars' geometry was 'within spec' when your shop inspected it?

OR that they were out of spec, but could be adjusted properly to lessen wear?



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I've said it previously in this Topic: rapid rear tread wear is a byproduct of a suspension setup that is biased to provide good handling. As @Brutal mentioned, allowing for bushing flex can make a difference in tire life. BUT who's to say whether the factory specs were made to take the flex into account? Is there a way to measure the exact 'rolling alignment'?

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Perhaps I'm too sensitive to our cars' inputs, but we recently had an alignment done on our IRS-equipped SUV because its rear tires were 'feathering'. I immediately noticed afterwards that the rear end was more 'lively' than before.

 

no the factory specs are not setup to include bushing/ball joint/etc flex no cars are. WHY? because there are varying amounts of play between parts and cars. Mercedes realizes this which is why they say to set up with a presser bar in front. (google it) This takes into account THE CAR you are working on and no other since they are ALL different. cars of same make, model and year will be different based on the suspension age, initial tolerances from manufacture and pot holes and curbs. while you cant really do this in the rear, you can look at the tires and dial in more oe in for inside tire wear. In my experience you don't start getting camber wear until you hit about -2* camber. another reason the R models have larger rear toe links in the rear to stiffen up the suspension and reduce metal deflection in hard cornering

 

Thanks, you taught me something. Never heard of a Presser Bar before this.

Hmmm, first Google attempt taught me a lot about sewing. So I included the word Mercedes and this came up:

https://www.summitracing.com/parts/sps-99918/overview/

I'm sure it has a highly-calibrated spring inside!

 

I use my hands, take out delflection and then let it go back to rest, then adjust in or out as needed and check again