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1 excerpts.

Reddit thread: How tight is too tight for an axle bolt?¶

reddit.com/r/MechanicAdvice/comments/w5qnjk · p. 1 · Applies to: 450, 451, 452, 453

Source: r/MechanicAdvice (score 1, 20 comments) Topic: axle bolt torque specification Models discussed: 450, 451, 452, 453 Solution status: unclear

Problem: After replacing the rear wheel bearing on a 2013 Smart fortwo, the axle bolt would not get tight with a ratchet, so the user tightened it until there was no play in the CV axle. Concerned about stripping the bolt and potential damage.

Solution: Torque spec is 2-stage and model-dependent: for 450.3/4 and 452.3/4 is 30 nm then 90 degrees; for 451.3/4 is 45 nm then 90 degrees. Going too tight can cause premature bearing failure. The proper torque specification must be followed rather than tightening until play is gone.

Key facts: - 2013 Smart fortwo requires two-stage torque procedure for axle bolt - Models 450.3/4 and 452.3/4: 30 nm + 90 degrees - Models 451.3/4: 45 nm + 90 degrees - Over-tightening axle bolt can cause premature wheel bearing failure - Proper torque spec must be used; tightening by feel until play disappears is incorrect procedure