Applies to: 1971-1989 Mercedes-Benz SL (R107 / W107 / C107): 280SL, 350SL, 380SL, 420SL, 450SL, 500SL, 560SL and the related SLC coupes.
The R107 had one of the longest production runs of any Mercedes, so "the SL" covers a lot of cars and a couple of different engines. Chassis fasteners (suspension, steering, brakes, wheels, and the rear axle) are common across the whole range. The engine values here come from the factory manual for the M117 V8 (560SL) and apply broadly to the M116/M117 V8 family (380/420/450/500/560). If you've got the M110 six in an early 280SL, the chassis numbers still apply but treat the engine-internal specs as V8-specific.
Always use a calibrated torque wrench. Replace self-locking nuts and necked-down (stretch) bolts after removal. Mercedes calls this out constantly on the R107 and they mean it. Where the factory specifies a torque-angle ("tighten to X, then turn Y degrees"), the angle is not optional; it's how the bolt reaches its real clamp load.
Quick Reference: The Specs Everyone Looks Up
The R107 specs people reach for most. Start here; the detailed system-by-system tables are below.
- Wheel (lug) bolt torque: 110 Nm (81 lb-ft), M12x1.5, ball seat. The single most-looked-up number; full notes in the Wheels table.
- Front hub / wheel-bearing torque: there isn't one. The R107 front bearing is set to endplay/rolling resistance, not torqued to a value. See the Front Suspension note.
- Firing order: 1-5-4-8-6-3-7-2 (V8).
- Valve adjustment: none. The M117 uses hydraulic self-adjusting lifters, so there's nothing to set. If something's ticking, that's a lifter/oil-pressure conversation, not a lash adjustment.
- Spark plug gap: 0.8 mm (0.032 in). (Widely documented; confirm against the plug you're running.)
- Wheel bolt pattern: 5x112, M12x1.5 ball-seat bolts; 66.5 mm hub bore.
- Tire pressure (cold): up to 110 mph: front 2.0 bar (29 psi), rear 2.4 bar (35 psi). Above 110 mph: front 2.2 bar (32 psi), rear 2.5 bar (36 psi).
- Rear axle ratio: 2.47:1, limited-slip (560SL).
Fluid Capacities
Engine oil and coolant change with the engine; everything else is common across the range. Liters are the factory figure, US quarts in parentheses.
By engine (oil and coolant):
| Engine / trim | Engine oil (with filter) | Coolant (total) |
|---|---|---|
| 280SL (M110 2.8 six) | 6.5 L (6.9 qt) | ~12 L (12.7 qt) |
| 300SL (M103 3.0 six) | 6.5 L (6.9 qt) | ~10 L (verify on a 300SL manual) |
| 350SL / 380SL / 420SL (M116 V8) | 8.0 L (8.5 qt) | 12.5 L (13.2 qt) |
| 450SL / 500SL (M117 V8) | 8.0 L (8.5 qt) | 13.5 L (14.3 qt) |
| 560SL (M117 5.6 V8) | 8.0 L (8.5 qt), +0.5 L with oil cooler | 12.5 L (13.2 qt) |
The inline-six oil figures (6.5 L) are owner/supplier consensus rather than factory-V8-manual values, so fill to the dipstick instead of dumping in a fixed amount. On the 560SL the factory capacity table prints 12.5 L while the generic M117 cooling table says 13.5 L; either way, fill to the mark and bleed the system.
Common across the range:
| System | Capacity | Type |
|---|---|---|
| Automatic transmission | 4-speed (722.3 / 722.4): about 7.7 L at a fluid change. Early 3-speed (722.0, 350 / 450SL): about 7.9 L | Dexron II ATF (MB 236.x) |
| Rear axle / differential | 1.3 L | Hypoid SAE 90; limited-slip takes MB LSD oil (000 583 09 04) |
| Power steering | 1.4 L | ATF / MB power-steering fluid |
| Fuel tank | 85 L on later cars (about 11.5 L reserve); 90 L on many earlier trims | Unleaded |
| Brake fluid | about 0.5 L (system) | DOT 4 |
Transmission generation matters more than trim: the early 350 / 450SL ran the 722.0 three-speed, while later cars and both sixes got the 722.3 / 722.4 four-speed. Confirm which box you have before buying ATF.
How to Read This Guide
- All primary values are in Newton-meters (Nm), the unit the factory manual uses, with lb-ft alongside for convenience.
- A range (e.g. 70-80 Nm) is the factory tolerance; aim for the middle unless a step says otherwise.
- "+ angle" means torque-to-yield: set the initial torque, then rotate the fastener the listed angle with a plain wrench (not the torque wrench).
- "Lubricated" vs "dry" matters: an oiled thread reaches a different clamp load at the same reading. Follow the condition noted.
Engine
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Cylinder head bolts (M10) | 30 - 60 - 60 | 22 - 44 - 44 | 3 stages. Stage 1: 30 Nm. Stage 2: 60 Nm in the diagram sequence. Stage 3 (after - 10 min settling, engine cold): loosen each bolt individually, then retorque to 60 Nm. Oil threads + bolt-head contact. Not torque-to-yield; there is no final angle stage. |
| Cylinder head cover (valve cover) bolts | 3 | 2 (~27 in-lb) | Yes, three. Very low, so use a 1/4" drive wrench, tighten crisscross. Over-torquing warps the cover and causes the classic R107 valve-cover oil weep. |
| Fuel injection valves to cylinder head | 10 | 7 (~89 in-lb) | |
| Camshaft sprocket bolt (M14x1.5) | 100 | 74 | Necked-down bolt; do not turn the engine over by this bolt. |
| Hydraulic valve-clearance compensating element (in head) | 60 | 44 | The M117 has hydraulic self-adjusting lifters, so there is no manual valve lash adjustment. This is the torque for the threaded element body. |
| Main bearing cap nuts (M10) | 50 | 37 | Rebuild. Tighten in the bearing-cap diagram sequence; lubricate threads + contact faces. |
| Main bearing cap side bolts | 50 | 37 | Must be grade 10.9. |
| Connecting rod nuts (M10) | 40-50 + 90-100 deg | 30-37 + angle | Rebuild. Lubricate nut face + rod-bolt thread. Without an angle gauge, swing the full angle in one motion with a plain wrench. |
| Crankshaft center (damper) bolt, 3-spring (early) | 270-330 | 199-243 | Bolt M18x1.5. |
| Crankshaft center (damper) bolt, 4-spring (from 1985) | 370-400 | 273-295 | Use this value if the later 4-diaphragm-spring damper is fitted. |
| V-belt pulley + vibration damper bolts (M8x22, x6) | 35 | 26 | No spring washers. |
| Driven (flex) plate to crankshaft (M12x1.5) | 30-40 + 90-100 deg | 22-30 + angle | Automatic-transmission drive plate; necked-down bolts, torque-to-angle. |
| Timing chain tensioner screws to cylinder head (M8x30) | 25 | 18 | |
| Timing chain tensioner coupling nut | 90 | 66 | |
| Spark plugs | 25-30 | 18-22 | Steel plug into aluminum head. Firing order 1-5-4-8-6-3-7-2. |
| Engine oil drain plug, M26 (R107 oil pan) | 50 | 37 | This is the plug on the R107 pan. New sealing washer each time. |
| Engine oil drain plug, M12 (Model 126 variant) | 40 | 30 | Listed only to disambiguate, not the R107 pan plug. |
| Air-oil cooler drain plug | 35 | 26 | |
| Oil filter lower-part attaching screw (Model 107) | 35 | 26 | The 25 Nm figure on the same factory page is the Model 126 central screw, not this. |
| Oil pan to crankcase bolts, M6 | 10 | 7 (~89 in-lb) | |
| Oil pan to crankcase bolts, M8 | 25 | 18 | |
| Oil pan lower part to oil pan, M6 | 10 | 7 (~89 in-lb) | Factory lists 10-11 across two sections; the 1 Nm spread is immaterial. |
| Rear engine mount set screw | 30 | 22 | Fit the mount without preload first. |
Cooling System
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Coolant (water) pump screws to crankcase (M8) | 25 | 18 | M8x30 / M8x65 / M8x85 all 25 Nm. |
| Thermostat cover combination screws (M6x20) | 10 | 7 (~89 in-lb) | Renew the sealing rings. |
| Radiator drain plug | 6-10 | 4-7 (~53-89 in-lb) | About 8 Nm. (The "1.5-2 Nm" you'll see floating around is the Model 126 plug, not the R107.) |
| Crankcase / engine-block coolant drain plug | 25 | 18 | One on each side of the V8 block; value is per plug. Replace the sealing washer. |
| Oil-cooler hose coupling nut (lube oil) | 25 | 18 |
Fuel, Intake & Exhaust
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Intake manifold mounting bolts | no factory spec | n/a | The factory manual gives a sequence, not a number: tighten from the inside outward with new gaskets. Community-practical value for these M8 bolts is roughly 20-25 Nm (15-18 lb-ft), snugged to seal the gasket donuts. Don't treat that as a factory figure. |
| Exhaust manifold to cylinder head (nuts) | see note | n/a | The factory manifold section specifies new self-locking nuts + gaskets (metal side toward the head) but does not publish a torque. These are M8 nuts; community practice is ~20-30 Nm. Do not use 75 Nm; that's the adjacent engine-mount value and will pull the studs. |
| Front exhaust pipe flange to manifold | 20-25 | 15-18 | Don't fully tighten until the whole system is hung in its rubber mounts. |
| Oxygen (O2) sensor screws | 25 | 18 | Coat threads with high-temp anti-seize; renew the screws. |
| Exhaust bolts to muffler | 25 | 18 | Renew the bolts. |
| Exhaust side-support bolts | 20 | 15 | |
| Injection lines to fuel distributor | 10-12 | 7-9 (~89-106 in-lb) | |
| Injection lines to injection valves | 10-15 | 7-11 (~89-133 in-lb) | |
| Fuel pump check-valve acorn nut | 22 | 16 | Renew the copper sealing rings. |
Drivetrain (Driveshaft, Rear Axle, Differential)
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Rear axle (CV) shaft screw, M10 | 70 | 52 | Threads + screw head lubricated. |
| Rear axle (CV) shaft screw, M12x1.5 | 135 | 100 | Unlubricated. |
| Rear axle shaft to flange, M12 hex | 95 | 70 | Later versions, with thick washer. |
| Rear axle shaft to flange, M8 hex | 30 | 22 | Later version with clamping disc + spacer. |
| Flex disc (guibo) self-locking nuts, M10 | 45 | 33 | Always renew the nuts. |
| Flex disc (guibo) self-locking nuts, M12 | 65 | 48 | Always renew the nuts. |
| Propeller shaft clamping/lock nut | 30-40 | 22-30 | |
| Rear axle carrier mount, front (hex-socket) | 60 | 44 | Self-locking. |
| Rear axle carrier mount, rear (special screw) | 110 | 81 | Spherical contact + sleeve. |
| Semi-trailing arm to rear axle carrier (nut) | 120 | 89 | |
| Differential ring-gear screws, small center piece | 100 | 74 | Self-locking. |
| Differential ring-gear screws, large center piece | 120 | 89 | |
| Drive pinion self-locking nut | 100 | 74 | Renew the nut. |
| Rear axle end cover to housing (hex bolts) | 45 | 33 | Clean the parting face, apply sealant. |
| Rear axle housing closing plug | 45 | 33 |
Automatic Transmission (722.3)
The R107 V8s (380/420/450/500/560 SL) use the Mercedes 722.3 four-speed automatic (early 280SL/350SL used the 722.1). Heads up: these are not from the R107 factory engine/chassis manual; that manual doesn't cover the transmission, so these are compiled from Mercedes community / 722-series service references. Verify against a 722.3 transmission manual before any rebuild-critical work.
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| ATF oil pan bolts | 8 | 6 (~71 in-lb) | Use a low-range / in-lb wrench, tighten in stages, since over-torquing warps the pan and causes leaks. Well-corroborated across multiple sources. |
| Torque converter to driven (flex) plate bolts | 42 | 31 | Grade 10.9, dry. Forum-consensus value; confirm for your transmission. |
| Torque converter drain screw | 14 | 10 | From MB service document 2702. |
Deliberately omitted (couldn't be reliably sourced for the 722.3): bell-housing (transmission-to-engine) bolts, transmission mount / crossmember bolts, and the ATF pan drain plug (sources conflict, 14-22 Nm). Pull these from a dedicated 722.3 manual rather than trusting a guessed number.
Front Suspension
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Steering-knuckle arm to knuckle (hex bolts) | 80 | 59 | |
| Guide (upper) ball-joint nut | 60 | 44 | MB calls the upper joint the "guide joint." Self-locking; renew on principle. |
| Supporting (lower) ball-joint nut | 80 | 59 | MB calls the lower joint the "supporting joint" (it's load-bearing, so higher torque than the upper). |
| Steering-knuckle stop screw | 45 | 33 | |
| Lower wishbone eccentric (camber) cam-bolt nuts | 120 | 89 | Highest fastener in the front end. |
| Upper control arm bearing bolts | 60 | 44 | |
| Track rod / tie-rod-end ball-joint nuts | 35 | 26 | Fit a new cotter pin. |
| Front lower shock absorber nuts | 20 | 15 | |
| Front anti-roll (torsion) bar bearing bolts | 20-25 | 15-18 |
Note on front wheel bearings: the R107 front bearing is set to endplay/rolling resistance, not a torque spec. Don't look for a spindle-nut torque number; adjust it to the factory preload procedure.
Steering
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Steering gear to frame side member | 70-80 | 52-59 | Install at 80; renew the locking screws. |
| Pitman-arm self-locking nut | 160-200 | 118-148 | |
| Steering coupling hex-socket screws | 25 | 18 | |
| Tie rod / drag link castle nut | 35 | 26 | Reference value; fit a new cotter pin. |
| Steering damper to drag link (bolt) | 45 | 33 | |
| Idler (intermediate) arm mounting nut | 120 | 89 | Self-locking. |
| Steering wheel nut, M14x1.5 | 50 | 37 | |
| Steering wheel nut, M16x1.5 / M18x1.5 | 80 | 59 | |
| Power-steering high-pressure hose to steering box | 25-30 | 18-22 | |
| Power-steering return line to steering box | 35-40 | 26-30 |
Brakes
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Front caliper to steering knuckle (fitted bolt) | 115 | 85 | |
| Front brake disc to hub (retaining screw) | 115 | 85 | Self-locking hex-socket screw. |
| Rear caliper to wheel carrier (hex bolt) | 90 | 66 | New self-locking hex bolts or new locking plate on axles without starting-torque compensation. (This is the rear; don't confuse it with the front's 115 Nm.) |
| Brake hose to caliper | 15 | 11 | Distinct fastener, not the mounting bolt. |
| Master cylinder to booster (nuts) | 15 | 11 | |
| Brake line fitting on master cylinder | 10 | 7 (~89 in-lb) | |
| Rear brake carrier / parking-brake spreader screws | 50 | 37 | Self-locking (from Oct 1978), single-use. |
| Brake lines to ABS hydraulic unit | 14 | 10 | |
| ABS front wheel-speed sensor screw, to Sept 1985 | 30 | 22 | Self-locking. |
| ABS front wheel-speed sensor screw, from Sept 1985 | 22 | 16 | Single-use. |
Wheels
| Component | Torque (Nm) | Torque (lb-ft) | Notes |
|---|---|---|---|
| Wheel (lug) bolts | 110 | 81 | M12x1.5, spherical (ball) seat. Steel and forged-alloy rims. Tighten crosswise in steps. If using an impact wrench, run it to ~100 Nm then finish to 110 with a click wrench, and ignore the "60-70 Nm under a single impact" figure in the manual, that's a warning about impact-wrench behavior, not the spec. |
General Tightening Torques (Standard Fasteners)
General reference values for standard metric fasteners not given a specific torque elsewhere in this guide. They assume clean, dry threads in good condition. A specific factory value always wins: if Mercedes lists a torque for a given fastener, use that. Knock off roughly 10-15% if the threads are oiled or anti-seized.
| Bolt size | Grade 8.8 (Nm / lb-ft) | Grade 10.9 (Nm / lb-ft) |
|---|---|---|
| M6 | 9 / 7 | 13 / 10 |
| M8 | 22 / 16 | 31 / 23 |
| M10 | 43 / 32 | 61 / 45 |
| M12 | 75 / 55 | 105 / 77 |
| M14 | 118 / 87 | 165 / 122 |
These are standard DIN/ISO 898 metric torque values (the R107 manual gives torques per job and has no general size/grade chart). Published charts vary by about 15% depending on assumed thread friction, so treat these as conservative guidance.
A Few Things Worth Knowing
Self-locking nuts and stretch bolts are one-time parts. The R107 manual is relentless about this: connecting rod nuts, flex-disc nuts, flywheel/drive-plate bolts, ball-joint hardware, and most ABS and brake-carrier screws are meant to be replaced, not reused. Reusing a stretched bolt is how a "torqued to spec" fastener still backs off.
Torque-angle isn't a suggestion. The rod bolts and drive-plate bolts finish on an angle, not a number. The initial torque just seats everything; the angle is what sets the clamp load. Get a cheap angle gauge. (Note: the head bolts are the exception; they're a flat 30/60/60 Nm with a settling break, not a torque-to-yield angle.)
Watch the Model 107 vs 126 mix-ups. This manual shares tables with the W126, and a few values interleave: the oil drain plug (R107 = M26 = 50 Nm, not the M12/126 = 40 Nm), the oil-filter screw (107 = 35 Nm, not the 126's 25 Nm), and the radiator drain plug (107 = 6-10 Nm, not the 126's 1.5-2 Nm). The values above are the R107 picks.
Engine vs chassis scope. Suspension, steering, brake, wheel, and rear-axle values carry across the R107 range. The engine numbers here are the factory M117 V8 specs (560SL). They're representative of the M116/M117 V8 family; the early M110 six differs internally.
Got questions, or a value you want us to add? Tag us on socials or hit us at info@treedylabs.com. Working on an R107? Show us the build when it's done. We actually want to see it.