Torque settings
Working on your car means you have to torque parts up when you fit them. Using correct torque levels is very important. Bolts will be tensioned when torquing up.
Always use a torque wrench when installing parts on your car!
Too much tension means the bolt will be stressed too much and can ultimately break. Not enough tension means the bolt can either run loose or it can move around. This will damage the bolt and it's brackets. This can ultimately also lead to catastrophic failures.
Only use 8.8 grade bolts in suspension applications. (wishbones, dampers etc.) 10.9 grade or even worse 12.9 grade bolts are hardened. The hardening process will improve the maximum possible load on the bolt, but it will also make the bolt relatively brittle. Within suspension parts, you would rather see bolts bend than sheer. 8.8 grade bolts have the tendency to bend, any hardened bolts have the tendency to sheer.
Standard torque settings per bolt size
Below is a guideline to the torque levels used on Metric bolts. Bolt grades are printed on the head of the bolt. These are for coarse-thread bolts. Fine-thread bolts typically have torques about 10% lower to give the same tension.
| Bolt Size | 8.8 | 10.9 | 12.9 | A2-70 (Stainless) |
|---|---|---|---|---|
| 6mm (M6) | 9Nm | 13Nm | 14Nm | 7Nm |
| 8mm (M8) | 23Nm | 33Nm | 40Nm | 17Nm |
| 10mm (M10) | 45Nm | 65Nm | 70Nm | 33Nm |
| 12mm (M12) | 80Nm | 115Nm | 125Nm | 57Nm |
| 14mm (M14) | 125Nm | 180Nm | 195Nm | xx |
| 16mm (M16) | 195Nm | 280Nm | 290Nm | xx |
Note than when fitting bolts into Ally threads like rivnuts, manifolds and S1 uprights then the torque may need to be reduced.
Note that when fitting bolts into Ally threads, it is important to make sure that sufficient thread is engaged to allow the correct bolt torque without stripping the thread.
Special note for Mr. Wiki - This is the thread size, not the head size.
K-series engine mounts
| Engine mount torque settings (K-Series) | Nm |
|---|---|
| RH engine mounting bracket to engine (bridge bracket to mounting bracket) |
145 |
| RH engine mounting bracket to rubber mounting (bridge bracket to hydramount top stud) |
82 |
| RH engine rubber mounting to chassis | 45 |
| RH engine steady arm bolts | 87 |
| LH engine mounting bracket to rubber mounting | 82 |
| LH engine mounting bracket to engine | 45 |
| Lower steady arm bracket to sump | 80 |
| Lower steady arm bolts | 77 |
Use Permabond A130(A912E7033V) on the sump end bolt on the lower steady arm
S2 K-series front suspension
| Front suspension torque settings (S2 K-Series) | Nm |
|---|---|
| Upper and lower wishbone pivot bolts | 45 |
| Upper swivel joint to steering arm | 55 |
| Lower swivel joint to plinth | 55 |
| Steering arm to hub carrier | 45 |
| Track rod end to steering arm | 30 |
| Damper to lower wishbone | 45 |
| Damper to top anchor bracket | 45 |
| Damper anchor bracket to chassis | 25 |
| Hub bearing unit to hub carrier | 90 |
| Brake caliper to hub carrier | 45 |
| Anti-roll bar rubber bush mounting clamps | 25 |
| Anti-roll bar drop links | 45 |
K-series rear suspension
| Rear suspension torque settings (S1/S2 K-Series only!) | Nm | ||||||
|---|---|---|---|---|---|---|---|
| Upper and lower wishbone pivot bolts | 45 | ||||||
| Upper and lower swivel joint ball pins | 55 | ||||||
| Upper swivel joint plinth to hub carrier | 45 | ||||||
| Toe-link outer ball joint to hub carrier S1 alloy | 45* | Toe-link outer ball joint to hub carrier S1 steel | 50* | Toe-link outer ball joint to hub carrier S2 steel | 50* | Toe-link outer ball joint to hub carrier S2 steel taper shank | 55* |
| Toe-link inner ball joint/wishbone to sub frame S1 | 45* | Toe-link inner ball joint/wishbone to sub frame S2 | 50* | ||||
| Toe link ball joint lock nuts | 55 | ||||||
| Damper to lower wishbone | 45 | ||||||
| Damper to chassis | 45 | ||||||
| Upper brake caliper to hub carrier (M10) | 45 - 50 | ||||||
| Lower brake caliper to hub carrier (M8) | 26 - 30 | ||||||
| Hub bearing unit to hub carrier | 90 | ||||||
| Rear hub nut | 220 |
- see Lotus Service Bulletin 2003/11 issue 6.
Note: S2/S3 Toyota settings need to be checked/confirmed.