General remarks
Automobiles use parts with metric threads in accordance with ISO standards.
Nuts, bolts and screws with damaged threads must be replaced with new ones. Running a damaged thread with a die or tap leads to a weakening of the thread and to an increase in the gap in the thread. It is not recommended to run the thread.
If a bolt is replaced, it is necessary to ensure that the new bolt has a strength index not lower than the one being replaced. Nuts with cotter pin slots should not be loosened to align the cotter pin holes. The exception is when this is provided for in the adjustment instructions.
Do not allow oil or grease to enter blind holes with threads. When tightening a bolt with a small clearance along the thread, oil that gets inside the hole is compressed and can lead to destruction of the housing.
Always tighten a bolt or nut to the recommended torque. Damaged or rusted threads will increase the thread tightening torque.
To check the tightening torque of a bolt, loosen it a quarter of a turn and then retighten it to the required value.
Before tightening, lubricate the threads with a small amount of oil. The exceptions are threaded parts lubricated with sealant and self-locking nuts.
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