New tech mounting wheels back on cars.

Proper Lug Nut Torque Procedure:

1. Clean threads - Remove dirt/debris from wheel studs and hub surface. Dirty threads cause inaccurate torque readings.

1. Apply specified torque - Use a calibrated torque wrench to tighten to manufacturer specs (typically 80-120 ft-lbs for most cars, but check your service manual). Tighten in a star/crab pattern to ensure even pressure.

1. Torque when wheels are off the ground - This prevents suspension components from creating false torque readings.

Re-torque Requirement:

Yes, you should have the customer return after 50-100 miles. Here's why:

• New wheel studs can experience "embedment" - microscopic settling that reduces clamping force
• Brake rotor/drum may shift slightly during initial heating/cooling cycles
• Aluminum wheels are particularly susceptible to torque loss

Legal/Code Considerations:

• Many states require disclosure of torque specifications in writing
• Some jurisdictions mandate re-torque procedures for commercial vehicle work
• Check your local motor vehicle codes - some require written re-torque notices

Best Practice: Provide the customer with a written notice stating: "Return for re-torque after 50-100 miles. Failure to do so may result in wheel separation."

Bottom Line: While not always legally required for passenger cars, re-torquing is industry best practice and protects you from liability. The cost of a re-torque visit is far less than a wheel loss accident.

Use a torque wrench, follow the star pattern, and document everything.

Torque Procedure (The "Right Way"):

1. Clean & Inspect: Wire brush studs, nut seats, and hub face. No lube on threads or seats (unless OEM specifies). Lube alters friction coefficients, leading to over-torquing/under-clamping.
2. Hand-Start: Thread all nuts by hand to prevent cross-threading.
3. Snug Pattern: Using a star/crisscross pattern, snug nuts to ~20–40 ft-lbs with a torque wrench or torque stick (impact wrench only if using calibrated torque sticks).
4. Final Torque: In the same star pattern, torque to exact OEM spec (found on door placard or service info, not a generic chart). Click-type wrench: pull smooth, stop at click. Do not "double-click."
5. Verify: Go around once more in star pattern to confirm no movement at spec.

Re-Torque Requirement: YES, Mandatory.

• Physics: Settling (embedment relaxation) of paint, coatings, and metal-to-metal interfaces loses 10–30% clamp load in the first 50–100 miles.
• Liability: If a wheel departs, you own it. Most shops require return at 50–100 miles (check your shop policy/insurance).
• Procedure: Re-torque cold (vehicle sat 3+ hrs) to same spec, same star pattern. Loosen first? No. Just verify/apply torque. If it moves, it was loose.
• Documentation: Write "Re-torque required at 50 mi" on RO/invoice. Have customer sign acknowledgment.

Code/Std: TIA RIST Procedure (Industry Standard), SAE J2863 (Clamp Load), OSHA General Duty Clause (safe workplace). Never use impact gun for final torque.