Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Prevailing Torque Fasteners
Prevailing torque fasteners create a thread interface between the fastener and the fastener counterpart in order to prevent the fastener from loosening.
All Metal Prevailing Torque Fasteners
These fasteners accomplish the thread interface by a designed distortion or deformation in the fastener.
Nylon Interface Prevailing Torque Fasteners
These fasteners accomplish the thread interface by the presence of a nylon material on the fastener threads.
Adhesive Coated Fasteners
These fasteners accomplish the thread interface by the presence of a thread-locking compound on the fastener threads. Refer to the appropriate repair procedure in order to determine if the fastener may be reused and the applicable thread-locking compound to apply to the fastener.
| Callout | Component Name |
|---|---|
| 1 | Prevailing Torque Nut, Center Lock Type |
| 2 | Prevailing Torque Nut, Top Lock Type |
| 3 | Prevailing Torque Nut, Nylon Patch Type |
| 4 | Prevailing Torque Nut, Nylon Washer Insert Type |
| 5 | Prevailing Torque Nut, Nylon Insert Type |
| 6 | Prevailing Torque Bolt, Dry Adhesive Coating Type |
| 7 | Prevailing Torque Bolt, Thread Profile Deformed Type |
| 8 | Prevailing Torque Bolt, Nylon Strip Type |
| 9 | Prevailing Torque Bolt, Out-of-Round Thread Area Type |
A prevailing torque fastener may be reused only if:
- The fastener and the fastener counterpart are clean and not damaged
- There is no rust on the fastener
- The fastener develops the specified minimum torque against its counterpart prior to the fastener seating
| Application | Specification | |
|---|---|---|
| Metric | English | |
| All Metal Prevailing Torque Fasteners | ||
|
0.4 N.m | 4 lb in |
|
0.8 N.m | 7 lb in |
|
1.4 N.m | 12 lb in |
|
2.1 N.m | 19 lb in |
|
3 N.m | 27 lb in |
|
4.2 N.m | 37 lb in |
|
7 N.m | 62 lb in |
|
10.5 N.m | 93 lb in |
| Nylon Interface Prevailing Torque Fasteners | ||
|
0.3 N.m | 3 lb in |
|
0.6 N.m | 5 lb in |
|
1.1 N.m | 10 lb in |
|
1.5 N.m | 13 lb in |
|
2.3 N.m | 20 lb in |
|
3.4 N.m | 30 lb in |
|
5.5 N.m | 49 lb in |
|
8.5 N.m | 75 lb in |
| Application | Specification | |
|---|---|---|
| Metric | English | |
| All Metal Prevailing Torque Fasteners | ||
|
0.5 N.m | 4.5 lb in |
|
0.8 N.m | 7.5 lb in |
|
1.3 N.m | 11.5 lb in |
|
1.8 N.m | 16 lb in |
|
2.3 N.m | 20 lb in |
|
3.2 N.m | 28 lb in |
|
4 N.m | 36 lb in |
|
7 N.m | 54 lb in |
| Nylon Interface Prevailing Torque Fasteners | ||
|
0.3 N.m | 3 lb in |
|
0.6 N.m | 5 lb in |
|
1 N.m | 9 lb in |
|
1.3 N.m | 12 lb in |
|
1.8 N.m | 16 lb in |
|
2.5 N.m | 22 lb in |
|
3.4 N.m | 30 lb in |
|
5 N.m | 45 lb in |
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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