N54 crankhub and timing guide

The N54 is the engine that made the crankhub a household word in the BMW world. On this engine the vibration damper is a ring bolted to a hub, and the hub is clamped to the crank nose by one central bolt — the drive to the oil pump and timing chain sprocket runs through friction plates between those faces. The factory service documentation is blunt about what that means: the friction stack is a wear-and-installation-critical item, and the central bolt is a replace-every-time fastener. Here is every number the factory data carries for that job, and for the chain and VANOS work behind it — then the whole thing as one ordered sequence, every torque at the step that needs it.

The crankhub, factory view

The N54 damper R&R itself (11 23 010) is screws-out, damper-off — the hub underneath is untouched. The real crankhub work lives in the timing chain job (11 31 051), where the central bolt comes out and the hub comes off the crank nose. Two factory laws govern it:

• The N54 requires special friction plates between the friction surfaces. The factory documentation's words: the engine will incur damage if the friction plates are damaged or not fitted. They clip onto the sprocket/oil-pump module — check them every time the hub is off.
• The central bolt is torque-plus-angle and single-use. Lightly oil the screw and thread, then torque it in stages.

Crankhub torque table

Special tools

• 11 0 300 — locks the crankshaft at TDC (slides into the block; see the TDC-bore gotcha below)
• 11 4 280 — counterhold for the flywheel/engine locking during the chain job
• 11 9 260 — block crankshaft (engine or gearbox removed)
• 11 8 660 — block crankshaft on the gearbox (automatic)
• 11 8 180 — flywheel holding fixture (manual gearbox)
• 00 9 140 — secures the new central bolt during installation (magnet-mounted to the engine support)
• 11 4 281 / 11 4 283 — camshaft locking fixtures for timing check/adjust
• 11 8 520 — increment-wheel alignment fixture
• 11 9 340 + 00 9 250 — chain tensioner pre-tension tool and torque wrench (0.6 Nm)
• 00 9 120 — central-bolt socket for the camshaft adjuster bolts
• 11 9 221 + 11 9 224 (with 11 9 222) — front seal slackener: bolts to the hub and presses the old seal inward ~1 mm at approx. 20 Nm to break its grip
• 11 0 371 + 11 0 372 — front seal puller and spindle: the puller screws into the seal at 80 Nm, the spindle draws it
• 11 4 370 — press-out piston for the seal puller
• 11 9 232 + 11 9 234 — seal installer fixture, bolted to the hub
• 11 9 231 + 11 9 233 — draws the new seal in flush
• 3/4-inch drive socket, extension if needed — the central bolt's breakaway law, from the chain job's own text

The complete job, in order

Everything above, arranged as one linear job — the mechanic's checklist, not the topic shelf. Every step traces to the same factory documents as the tables; where those documents list preliminaries as a set rather than an order, the numbering below is one clean sequence through them. Practice the factory data does not carry is labeled as ours, never presented as factory.

Stage 0 — before the first bolt turns

Order the friction plates the day you schedule the job, not the day the engine is open — a damaged plate found at disassembly is the car sitting dead for a shipping box.

Preconditions, honestly split. The factory documents carry three: all spark plugs out (their own preliminary — and it makes the hand-rotation stages honest work), the adjuster base-lock check before any timing judgment, and the TDC-bore decoy law on automatics (Stage 2). They state no temperature precondition and nothing about the battery. Cold-engine working and a battery on a maintainer are our practice, not factory lines — this job means hours at the front of the engine and a first-start you want at full cranking voltage, and neither survives a half-charged battery.

Stage 1 — access: opening the front of the engine

The cited documents never touch the intake tract: no charge pipe, no intercooler, no airbox step appears in any of them. The list below is the complete factory access list — anything beyond it is your own choice, not a required step.

1. 01Front underbody protection out.
2. 02Fan cowl out.
3. 03Coolant expansion tank out — E89 only; it shadows the chain tensioner.
4. 04Cylinder head cover off. New gasket and well seals at refit; the cover's own torque state lives in the valve cover guide — which is honest that the N54 cover-bolt number is not carried in our factory extract.
5. 05All spark plugs out — M12x1.25, dry threads, 23 ± 3 Nm (17.0 ± 2.2 lb-ft) at refit. They are in your hand anyway; a set that was due goes back new.
6. 06Drive belt off, then belt tensioner off — M10x110 ISA screw, 40 Nm (29.5 lb-ft) at refit. The belt guide owns the routing and the preload safety law.
7. 07Vibration damper ring off: four ASA screws M8x16, 35 Nm (25.8 lb-ft) at refit. The ring unbolts from the hub face — no puller appears anywhere in the factory procedure.
8. 08Front crankshaft seal out, in the seal procedure's own order:
   1. 01Slacken it first: 11 9 221 onto the crankshaft hub, turn back 11 9 222, run the 11 9 224 screws down to approximately 20 Nm (14.8 lb-ft) — that presses the seal inward about 1 mm and breaks its grip on the bore.
   2. 02Screw 11 0 371 into the seal at 80 Nm (59.0 lb-ft), fit spindle 11 0 372, draw the seal from the crankcase — repeat the pull if it fights.
   3. 03Free the seal from the puller by sawing it open at its cutting line.
9. 09The front fastener out — the timing-case fastener the cam fixtures sit over. Note its install law now: the bore faces outwards at refit.
10. 10Intake and exhaust adjusters off, in the factory's order:
11. 11Slide 11 0 300 in and rotate the crank at the central bolt until cylinder 1 is at firing TDC and the pin seats. On automatics the large decoy bore sits just before the real one — the test: with the pin in the correct bore, the engine cannot be moved at the central bolt.
12. 12Check the cams: intake cam at cylinder 6 pointing down at an angle to the left, exhaust to the right. Installed in the car, this check takes a mirror.
13. 1311 4 283 to the head, 11 4 281 across the camshafts.
14. 14Release both adjuster central bolts — grip the hexagon at the rear of the camshaft, counterhold 11 4 280 only. Both screws go in the bin; their M10x94 replacements arrive in Stage 4.
15. 15Chain tensioner out — cloth ready, a small quantity of engine oil follows the thread; keep it off the belt drive. If the tensioner will be reused, drain its oil chamber now: level surface, slowly compress, twice.
16. 16Detach both adjusters — turning the increment wheels aperture-down makes room. Label them as they come off: intake is marked EIN/IN, exhaust AUS/EX, and mixing them up is engine damage in the factory's own words.
17. 17Fixtures off, in reverse — 11 4 281, then 11 4 283. Leave 11 0 300 seated: the crank stays locked for the chain job that starts now.

Stage 2 — the hub: the chain job proper

The engine is already at firing TDC with 11 0 300 seated from the adjuster sequence; the chain job restates the lock — verify it rather than assume it.

1. 01Mark flywheel and transmission housing with a line — the external TDC reference every later check leans on.
2. 0211 4 280 stays fitted. The factory's words: do not remove.
3. 03Hold the crank, tool by situation: engine or gearbox removed → 11 9 260; automatic → 11 8 660 on the gearbox; manual → 11 8 180 with its screws, securing the flywheel in the arrow's direction.
4. 04Remove 11 0 300, then release the central bolt with a 3/4-inch socket and extension if needed. Bolt out, hub off the crank nose toward the front.
5. 05Screw plugs out, top and bottom — M18x1.5, 25 Nm (18.4 lb-ft) at refit.
6. 06Chain drive screw out at the top — M6x35, 8.5 Nm (6.3 lb-ft) at refit.
7. 07Screw out at the bottom — M8, 20 Nm (14.8 lb-ft) at refit.
8. 08Side screws out — M6x35, 8.5 Nm at refit — and lift the timing chain module out upward with chain and sprocket.
9. 09The friction stack on the bench, piece by piece:
   1. 01Plates (1 and 2) are clipped into place on the sprocket/oil-pump module — inspect both, replace if damaged.
   2. 02Friction plate (3): confirm its installation position.
   3. 03Friction plate (1) refits pushed on without retainers.
   4. 04The sprocket: the collar points toward the crankshaft — incorrect assembly is engine damage, the factory's words, not ours.
   5. 05Chain, rails, and guides: look them over while they are in your hand — the torque table's section above carries what the factory carries.
   6. 06The crank nose: the factory data states no nose measurement and no wear limit — the plate inspection is its answer. If the hub has slipped, the nose check that matters (degrease, burr and damage) lives in the splined install guide, and the failure anatomy lives in the conversions guide.

Stage 3 — the hub decision point

1. 01Stock stack: continue to Stage 4 — new central bolt, factory torque-plus-angle, everything in order.
2. 02Splined hub: press-and-broach, no drilling — the splined install guide carries the old-bolt press stage, the 75 ft-lb pre-torque, and the bolt-capture companion that goes with it.
3. 03Pinned hub: jig-drilled dowels — the pinned install guide carries the foil-shimmed jig, the carbide law, depth stops, and the pan-off chip protocol.
4. 04Bolt capture alone: the crank bolt capture guide — what a capture fixes, what it cannot, and the bolt-head clocking problem.
5. 05The decision itself — stock versus capture versus pinned versus splined, with the honest comparison — is the conversions guide's whole job.

Whichever path you take, the chain, module, and timing work in Stage 4 is the same; only the hub-and-bolt endgame differs, and each upgrade page carries its own final torques. The numbers below are the stock stack's.

Stage 4 — reassembly, every torque at its step

1. 01Seat the chain and sprocket: pull the chain up until the sprocket engages the chain guide, and install both in that position. Hold the chain under tension the whole time — the factory's warning is that the chain jams on the module otherwise.
2. 02Chain module in from above, its bolt home, gear wheels confirmed in position, hub in with its friction plate. The sprocket collar still points at the crankshaft.
3. 0300 9 140 with its magnet to the engine support, the new central bolt into its holder — the bolt does not start into the nose by hand with the module in the way.
4. 04New central bolt M16x80, screw and thread lightly oiled: 100 Nm (73.8 lb-ft), then 360° — crank still held by the transmission tool. 11 21 1AZ.
5. 05Screw plugs in: 25 Nm.
6. 06Top screw 8.5 Nm, side screws 8.5 Nm, bottom screw 20 Nm.
7. 07New front crankshaft seal, the install half of 11 14 005: clean and degrease the sealing surface at the crankcase partition; light coat of oil on the running surface; 11 9 232 with 11 9 234 screws to the hub; support bush (supplied with the seal, the only slip bush allowed) and seal onto the tool, the seal's groove aligned centrally to the crankcase partition; Loctite primer 171000 into both grooves and onto the partition, one minute of air; draw the seal in flush with 11 9 231 and 11 9 233; fill both grooves flush with sealing compound 128357 by injector or syringe; coat the compound with primer 171000. The factory's words on skipping any of that: the engine block will not be leakproof at the outside of the crankshaft seal.
8. 08Adjusters on: intake marked EIN/IN, exhaust AUS/EX, never interchanged. Installation position is freely selectable and the increment wheels fit either way. New M10x94 screws in, just started.
9. 09Set the timing (11 31 505): rotate the crank at the central bolt back to firing TDC of cylinder 1 and re-seat 11 0 300 — the decoy-bore law applies again — and take the crank-holding tool off; 11 4 283 to the head, 11 4 281 across the cams — if 11 4 281 will not seat, rotate the camshaft at its rear hexagon with 11 4 280 until it does; release both adjuster bolts; rotate the increment wheels until the retaining pins of 11 8 520 match up, push it onto the head, secure it with its M6x45 bolts (captive washers); the tensioner is still out — screw 11 9 340 into its bore; pre-tension the chain to 0.6 Nm (0.4 lb-ft) with 00 9 250; torque both adjuster bolts with 00 9 120: 20 Nm (14.8 lb-ft) + 180°. 11 36 1AZ. Then all special tools out — alignment fixture, pre-tension tool from the tensioner bore, cam fixtures, pin.
10. 10Chain tensioner in: new sealing ring — series production fits none, service must — then 55 Nm (40.6 lb-ft), and the factory law: do not retighten. The drain-if-reused ritual happened at removal in Stage 1.
11. 11Crank the engine twice at the central bolt, in the direction of rotation.
12. 12Check the timing (11 31 005): bring the engine back to firing TDC of cylinder 1 — the flywheel mark from Stage 2 is the external reference — and seat 11 0 300 in the correct bore; adjusters must be at their locked base position, and after this job they are, because 11 8 520 set them there, but run the check as written; cams of both shafts at cylinder 6 pointing down at an angle, roller follower unactuated — a mirror, in the car; then 11 4 283 and 11 4 281 must both seat. If 11 4 281 will not seat, the timing is off: back to step 9. No exceptions, no shortcuts.
13. 13Damper ring on: four ASA M8x16, 35 Nm.
14. 14Belt tensioner on, 40 Nm, and the belt on — routing and preload law in the belt guide.
15. 15Spark plugs in: 23 ± 3 Nm, dry threads.
16. 16Head cover on with its new gasket — torque per the valve cover guide's honest state.
17. 17Coolant expansion tank (E89), fan cowl, underbody protection. The engine is assembled.

Stage 5 — verification and first start

The factory documents end at "assemble engine." Everything past that line below is our practice, labeled as such:

1. 01The rotation gate — already run at Stage 4 step 11, and it is the gate: two full revolutions by hand at the central bolt, uniform resistance, no lock-up, before the starter ever turns. That one is the factory's, not ours.
2. 02First start is a primed start: fill the oil filter housing, crank, and watch the pressure light — the oil system prime guide owns the whole ritual, and on this job it is the law twice over: the tensioner and both VANOS units spent the job drained and open.
3. 03Code check: VANOS correlation faults are the signature of timing a tooth off — the 2A82 and 2A87 pages cover what each one means. A clean cold start with no codes is the first timing proof.
4. 04Warm re-check, ours: at operating temperature, re-run the 11 31 005 sequence — lock check, TDC, fixtures — and look at every interface you touched for weeps, the new seal's grooves above all. The honest version: the head cover comes back off for the fixture half; weigh that against how steps 1 through 3 went.
5. 05Drive it, then look once more: the chain settles on its first heat cycles, so one more 11 4 281 seat-check after the first real drive closes the loop.

Timing chain, guides, and tensioner

Chain replacement is the same job as the crankhub — the chain module comes out as part of it. The rail and tensioner numbers:

The tensioner on its own (11 31 090) is an accessible job — coolant expansion tank out on an E89, then the tensioner unbolts with a cloth ready to catch the oil that follows. Keep that oil off the belt drive.

VANOS adjuster bolts

Opening those central bolts: grip the hexagon on the rear of the camshaft, release only with counterhold 11 4 280. Intake and exhaust adjusters are marked (EIN/IN vs AUS/EX) and are not interchangeable — mixing them up is engine damage, straight from the doc.

Checking and setting the timing

• Adjusters must be at their locked base position before you judge timing — check the lock and rotate the camshafts to lock them if needed.
• 11 0 300 in the correct bore, cylinder 1 at firing TDC, cams of both shafts at cylinder 6 pointing down at an angle, follower unactuated.
• 11 4 283 bolts to the head; 11 4 281 mounts across the camshafts. If 11 4 281 will not seat, the timing needs adjusting.
• Adjusting: release both adjuster central bolts (replace), align the increment wheels with 11 8 520, pull the tensioner, screw 11 9 340 in its place, pre-tension the chain to 0.6 Nm (0.4 lb-ft) with 00 9 250, then torque the adjuster bolts with 00 9 120.
• Crank twice in the direction of rotation and re-check.

Coverage notes

What the factory data does and does not carry: complete procedures, torques, and tooling for the damper, hub, chain, tensioner, and VANOS work — all of it above, traced to document ids. It does not carry failure-mileage statistics or a wear limit for the hub's friction surfaces; any "these fail at X miles" claim you read on a forum is folklore, not factory data. Treat the friction-plate inspection as the factory's answer to the question.

Every number on this page traces to the factory document ids listed in the sources, including the ordered sequence — it is the factory's own step order, with the torques carried to the steps that need them. What stays in the factory service documentation is the graphics, the zoomable views, and the live procedures; the sequence, the numbers, and the warnings are all here.