Nissan-Datsun 370Z Technical 11-027 Date: 110310 Tires - Preventing Tire Flat Spotting Classification: WT11-001

Nissan-Datsun 370Z Technical  11-027 Date: 110310
Tires - Preventing Tire Flat Spotting
Classification: WT11-001
Reference: NTB11-027
Date: March 10, 2011
NEW VEHICLE TIRE FLAT SPOTTING
APPLIED VEHICLES: New unsold Nissan dealer in-stock units
SERVICE INFORMATION
Temporary tire Flat Spotting is common on New Dealer In-Stock vehicles that have not been occasionally moved.
Flat Spotting can occur after the vehicle has been parked (not moved) for a few days, or longer. In most cases it is temporary. In extreme cases it can
be permanent.
As instructed in the Assurance Products Resource Manual, vehicles should be moved 12 inches, in one direction only, every 30 days to prevent tire
Flat Spotting.
  Page 273
New vehicle inventory vibration incidents related to storage Flat Spotting are not considered warrantable repairs.
If tire Flat Spotting has occurred, it can cause a vibration or shimmy condition that may be noticeable for the first several miles of driving.
Factors that can influence Flat Spotting:
^ Long storage time without moving the vehicle may result in permanent flat spots.
^ High performance and high speed rated tires are more prone to flat spotting due to the internal construction and nylon use in these tires.
^ Shorter sidewall tires do not absorb irregularities (flat spots) as well as taller sidewall tires.
^ In colder temperature tires are stiffer which increases the tendency to have flat spots and increases the drive time needed to remove them.
Refer to the Service Procedure below if you have tires with Flat Spotting.
SERVICE PROCEDURE
^ It is important to remove any temporary Flat Spotting prior to performing tire balance, tire run-out, and/or tire road force checks.
^ If the Flat Spotting is not removed it can result in incorrect measurements.
^ Temporary flat spots will return to original (near uniform) condition after driving for approximately 15 miles at highway speeds.
1. Drive the vehicle at highway speeds until the vibration (Flat Spotting) is eliminated.
NOTE:
^ In most cases, flat spot vibrations will be eliminated within 15 minutes (about 15 miles) of driving.
^ If the vehicle has been stored without moving for an extended time, it may be necessary to drive the vehicle up to 30 minutes (about 30 miles) at
highway speeds.
^ If the vibration goes away during the test drive, no further action is required.
^ If the vibration is not completely eliminated during the test drive go to step 2.
2. Within 10 minutes after driving the vehicle, lift the vehicle so there is no load on the tries.
3. Check the tire/wheel assemblies for balance, run-out, and road force variation. Correct as necessary.