S58 crankhub and timing guide

Honest opening, because this page earns its trust that way: the ISTA catalog carries no S58-only crankhub or timing-chain repair documents. What it carries is better than nothing and needs to be stated exactly — the S58 is based on the B58TU (the functional description says so in its first technical paragraph), and the B58-family repair documents carry validity scopes that explicitly include the S58. That is how the factory data serves this engine: through its architecture. Every number below is from a document whose validity covers the S58, or from the S58's own functional description.

What the S58 description documents

The S58B30T0 functional description gives the design facts that matter for this work:

• The S58 is based on the B58TU, with technical updates and modifications by M GmbH for racing duty — high-rpm concept, twin turbocharging.
• The **belt drive had to be adapted**: an additional tensioning pulley sits between the vibration absorber with belt pulley on the crankshaft and the A/C compressor, suppressing drive-belt vibrations on that span. On this engine the damper carries the belt pulley — that's the factory's own phrasing, "vibration absorber with belt pulley."
• The chain drive housing, VANOS solenoid mounts, and crankcase ventilation are all S58-specific parts.

Damper bolts

The torque block's validity names the S58 explicitly — both output classes (O and T), revision 0 — alongside the B58. Same TTY bolt set, same 40 Nm + 120°.

Belt pulley on the damper

That row comes from the adjuster-side document whose validity includes the S58 — relevant because the damper, pulley, and the extra tensioning pulley the S58 description calls out all live in the same front-end workspace.

Chain tensioner

Same story as the B58: tensioner-job documents whose validity includes the S58. Drain the oil chamber before reuse (level surface, slow compression, twice), and fit a new sealing sleeve on install.

Timing chains

The "Replacing both timing chains" document's validity includes the S58 for the G80 and G82, rear-wheel drive — that's the M3/M4 — alongside B58 variants. As with the B58, it is written as an engine-out, assembly-stand job. The numbers that matter inside it:

VANOS

Tools in this family of documents: the engine support for the assembly stand is listed for "Engine: B58; S58" specifically, the wrench socket 2450487 and adapter 2469138 serve the VANOS units, and the chain pre-tension fixture row (tool 11 9 900, 0.6 Nm on the tensioner) appears in the adjuster procedure.

Coverage verdict

Thin-but-real, and we'll keep saying exactly what that means:

• **Carried:** damper torque (explicit S58 validity), tensioner torque and procedure (explicit S58 validity), the engine-out timing chain job (explicit S58/G80/G82 validity), VANOS gear and central-valve torques, and the S58 functional description with the belt-drive and chain-housing facts.
• **Not carried:** an S58-specific damper R&R walkthrough, an S58-specific hub document, any in-car chain procedure, wear limits, or failure-mileage data. The S55's grip-disc law does **not** transfer to this engine — that's an S55 document, and claiming it applies here would be inventing data.

If you're doing this work, the B58 guide is the companion page — the procedures and tooling it lists are the ones the S58-scoped documents share.

Every number traces to the ISTA ids in the sources, and every claim about what the data doesn't carry is a claim you can verify against those same ids.