Rear tyre wear
#24
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No worries, I am guilty of the same on occasion. As long as it is a constructive discussion like this, go off at whatever tangent you like!
Meanwhile, I dropped my car in on Tuesday for the alignment, sunroof rattle (supposedly a known issue with a fixed solution), 1 wheel scuff repair and the first service. They have had the car for three days now with apparently no resolution for the rattle and they told me last night that they need the car for "a week or so". Given that I waited 1 month for an appointment, they had no loaner available and they don't set any expectations for when they can complete the work, I feel fairly confident that they have got themselves too much work on and my car is bottom of their list. This is the third poor service experience I have had with them, but all Houston Jag dealers are owned by the same company, so I have no choice but to go there. A complete shambles and certainly enough to put me off buying another Jag after this one. No wonder you don't see many Jags in Houston...
Tangential rant over!
Meanwhile, I dropped my car in on Tuesday for the alignment, sunroof rattle (supposedly a known issue with a fixed solution), 1 wheel scuff repair and the first service. They have had the car for three days now with apparently no resolution for the rattle and they told me last night that they need the car for "a week or so". Given that I waited 1 month for an appointment, they had no loaner available and they don't set any expectations for when they can complete the work, I feel fairly confident that they have got themselves too much work on and my car is bottom of their list. This is the third poor service experience I have had with them, but all Houston Jag dealers are owned by the same company, so I have no choice but to go there. A complete shambles and certainly enough to put me off buying another Jag after this one. No wonder you don't see many Jags in Houston...
Tangential rant over!
#25
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Got the car back last night - all work completed apparently successfully and no charge for anything! All hail, the Platinum Warranty.
Jagular - you win, sort of. The alignment was largely in spec, but the toe on the front right and left rear was a little out. I don't know if that could affect wear on the inside of the right rear, but I guess it could. For general info, pic of the before/after print out below, with specs for the XFR/Supercharged.
Jagular - you win, sort of. The alignment was largely in spec, but the toe on the front right and left rear was a little out. I don't know if that could affect wear on the inside of the right rear, but I guess it could. For general info, pic of the before/after print out below, with specs for the XFR/Supercharged.
#26
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Front toe equalizes while driving. The static numbers are measured relative to static spec but when on the move the rack slides over to equalize the toe. Not so at the rear. The left toe out would tend to pull the rear of the car to the left. Turning the steering wheel to counter this would quite probably result in the car appearing to steer straight but all four tires would be dragging to some extent as the car would tend to crab left. These effects would be small for such small amiunts of out of spec but over time could show up as uneven tire wear.
#27
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To the OP: I was going to say that the camber is usually not adjustable in the rear. Your wear looked like toe. It is the diff between the two rear toes that counts.
Last edited by MK 82; 01-27-2012 at 07:40 PM.
#30
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Yet another reason to be happy with my Base 18" wheels. Aside from the protection the extra rubber gives to the wheels from road hazards, I can rotate my tires as I don't have staggered widths either. Learned my lesson when I moved to a staggered widths on my NSX. Lost both front wheels to road hazard and went through rears quickly. I’ll just need to pick a mileage amount and do the rotations myself as I’m sure service appointments will be to long of an interval to approach this. But thanks to this discussion, at least I have a plan.
#31
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[QUOTE=MK 82;461183]Do you have a reference for this statement? I used to align cars for a living and have never heard this. Please share with us where you learned this.
Since the front wheels are free to pivot unless you hold the steering wheel it is self evident that the toe divides equally between the front wheels when the car moves. Caster ensures that this will occur.
When you aligned cars for a living you will recall the importance of ensuring that the steering wheel was centered before you commenced any measurement or adjustment. If you did not then the steering wheel would be off center as the car was driven. Then imagine centering the steering wheel but aligning the toe differently left to right. You will see that when the car moves the caster will force the wheels to trail straight and the steering wheel will be off center.
Since the rear wheels do not pivot any toe setting is locked in and can develop a thrust. This is why wear from incorrect toe always looks equal on front tires but can differ on rear tires. Uneven wear on front tires is due to incorrect camber. I discount uneven tire wear from driving habits and suspension design which is not due to incorrect alignment.
You would not necessarily need to know this to align correctly as long as you always set the steering wheel to dead center before you began.
Since the front wheels are free to pivot unless you hold the steering wheel it is self evident that the toe divides equally between the front wheels when the car moves. Caster ensures that this will occur.
When you aligned cars for a living you will recall the importance of ensuring that the steering wheel was centered before you commenced any measurement or adjustment. If you did not then the steering wheel would be off center as the car was driven. Then imagine centering the steering wheel but aligning the toe differently left to right. You will see that when the car moves the caster will force the wheels to trail straight and the steering wheel will be off center.
Since the rear wheels do not pivot any toe setting is locked in and can develop a thrust. This is why wear from incorrect toe always looks equal on front tires but can differ on rear tires. Uneven wear on front tires is due to incorrect camber. I discount uneven tire wear from driving habits and suspension design which is not due to incorrect alignment.
You would not necessarily need to know this to align correctly as long as you always set the steering wheel to dead center before you began.
#33
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The E diff is special. The earlier cars use an electronic diff effect using the ABS hardware to actually apply the brake to the wheel with low traction. The effect is exactly the same as for a mechanical LSD except you cannot spin both rear wheels.
The actual E diff adds an electronically controlled clutch pack inside the diff which allows both drive wheels to spin up under the right settings in the DSC.
Don't confuse the two types of slip control. The ABS system is for street use whereas the electronic clutch pack is for track use.
The actual E diff adds an electronically controlled clutch pack inside the diff which allows both drive wheels to spin up under the right settings in the DSC.
Don't confuse the two types of slip control. The ABS system is for street use whereas the electronic clutch pack is for track use.
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