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Autopapyrus · Subaru Forester (4th generation, SJ)
https://autopapyrus.com/guides/subaru/forester/choosing-lug-nuts-for-alloy-wheels/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Subaru Forester (4th generation, SJ): Choosing Lug Nuts for Alloy Wheels

The Forester SJ uses M12x1.25 fasteners with a 5x100 bolt pattern and a 56.1 mm hub center bore. The lug nut must match the wheel exactly in seat type (cone, ball or flat with washer) and thread length. A mistake in either of these parameters results in poor wheel retention and a risk of losing the wheel while driving.

Difficulty: Easy Time: 15-30 minutes Steps: 8 Tools: Lug wrench or socket for the nut (factory nuts are usually 19 mm), torque wrench, caliper, measuring ruler, jack, wire brush

Part

  • 🔩 M12x1.25 wheel lug nuts with a 60° conical seat, closed type, thread length 25-30 mm for alloy wheels. Set of 20 pcs
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes and 9 more. See manuals →

Step by step

8 steps
  1. Determine the thread. For this car it is M12x1.25 (not M12x1.5, as on many Japanese and other Asian models). Nuts with a 1.5 pitch should not thread onto the studs, and forcing them will strip the threads.
  2. Determine the seat type in the wheel's bolt hole. Factory Subaru alloy wheels generally require a 60° conical seat. If your wheel (especially an aftermarket one) has a spherical (radius) seat or a flat seat with a washer, choose nuts made specifically for it. Do not install a cone nut in a ball seat or a ball nut in a cone seat: contact will be along a narrow line, and the nuts will loosen.
  3. Check the thread length of the nut. Measure the depth of the wheel's bolt hole with a caliper. The nut must engage the stud by at least 6-8 full turns, and it must not bottom out on the stud end or on the brake disc or drum. For alloy wheels, a nut with a thread length of about 25-30 mm is usually suitable.
  4. Choose the nut design. For alloy wheels, a closed nut (with a cap) is better, since it protects the stud from corrosion. If the holes in the wheel are narrow, use thin-wall nuts rather than standard ones: a regular socket will not fit in there. For such cases, use a special thin-wall socket or a tube-type lug wrench.
  5. Check the wrench size. Factory nuts are usually 19 mm (sometimes 17 mm, depending on model year and trim). Make sure the chosen wrench fits and that the nut is not too narrow for the tool. For locking lug nuts, get the special key adapter.
  6. Remove the wheel and clean the hub and studs with a wire brush. Check the stud threads: they should be clean, without nicks. Apply a drop of clean oil to the nut seat, or none at all, but do not lubricate the studs heavily, so the tightening torque is not understated.
  7. Thread all the nuts on by hand until snug. They should turn without effort. If a nut is hard to turn, stop and check the threads.
  8. Tighten the nuts with a torque wrench in a crisscross (star) pattern, with the wheel lowered to the ground. The factory torque for this model is 120 N·m (89 lb-ft), but verify it in the Subaru service manual for your trim. Re-torque after 50-100 km of driving.

Common mistakes and warnings

  • Wheel fasteners directly affect safety. If you are unsure about nut and wheel compatibility (especially for aftermarket wheels with a different seat type), consult a tire shop or repair shop. Do not use nuts with a deformed seat or damaged threads. Do not tighten with an impact wrench without checking with a torque wrench.