UPDATE 5/1/2016
Of even more concern is a problem with the right upper control arm ball joint of my air suspension. Right now it just squeaks like mad (a little embarrassing at stoplights, to say the least) but eventually this will have to be replaced at a service center (the HV battery must be dropped out to perform the repair) and they can't tell me how long it will be safe to drive in its current condition. I was planning a trip to Vancouver this summer anyway, but it sounds like Tesla would like me there ASAP. I'm afraid I'll have to disappoint them. A trip of several thousand kilometers like that can't just be pulled together on a whim (I need to book time off work, book hotels, etc).
So the upshot is: One step forward, two steps back...
I had my upper control arm replaced via ranger service a month ago... one tech previously (Keith) mentioned he could do it in the field, but when the time came, a different tech + Dave (?) the new guy both worked on it. Dave mentioned he didn't know how he would have done it solo - maybe that's why it isn't happening in the field now? A bit worrisome that we both had the same issue, to me it doesn't bode well. I'm a bit worried about my other side now.
From the invoice:
Concern: Customer states: steering squeak - Keith heard it. Suspects the RF upper control
arm balljoint being dry and squeaking on turns
Corrections: Exterior NVH General Diagnosis
Road tested vehicle and confirmed RF upper ball joint causing noise and excessive play.
Corrections: Control Arm - Upper - Front - RH
Replaced Control Arm - Upper - Front - RH.
Performed function check after repair procedure = OK.
Parts Replaced or Added
Part Quantity
UPPER CONTROL ARM SUSPENSION
ASSEMBLY - FRONT RIGHT - DUAL
MOTOR (1043966-00-A)
BOLT, M10x1.50x100MM, ZINC ALUMINUM
(1004357-00-A)
NUT, M10x1.50mm (2007059-00-B) 2
BOLT, BUTTON HEAD, M10x1.50x57MM,
ZINC ALUMINUM (1004350-00-A)
NUT, M10x1.50MM, ZINC ALUMINUM
(1004351-00-A)
Corrections: Perform Validation Test Drive