Subaru EJ25 Flywheel Torque Pattern Diagram
Subaru EJ25 flywheel/drive-plate eight-bolt pattern with cited 2004 non-STI 72 N-m and STI 77 N-m branches and contamination checks.
In the cited 2004 Subaru Impreza H4DOHC service data, flywheel/drive-plate hardware is 72 N-m (52.8 lb-ft) for non-STI models and 77 N-m (56.8 lb-ft) for STI models. Start the matching eight bolts by hand and use an opposite-side crisscross pattern. Confirm the exact model, transmission and flywheel/drive-plate stack because EJ25 spans many SOHC, DOHC, turbo and non-turbo applications.
The flywheel or flexplate is both a rotating engine component and the connection to the clutch or torque converter. Uneven seating at the crank flange can create runout, starter-ring-gear problems, vibration or bolt fatigue. For the Subaru EJ25 DOHC, the correct value is inseparable from crank flange, fastener, thread treatment and installed transmission hardware.
The cited manual assigns different T2 values to STI and non-STI cylinder-block illustrations. Choose by the exact model branch, not merely by the EJ25 family label.
The interactive pattern alternates across the bolt circle to draw the part onto the crank flange evenly. It is a tightening controller, not a claim that every engine carrying the same family name has the same bolt count. Compare the actual flange, service illustration and replacement-part instructions before applying torque.
Interactive Subaru EJ25 DOHC crank-flange sequence
STAR PATTERN
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A 8-fastener opposite-side controller. Select 1 through 8; the physical labels around the circle are 1-5-2-6-3-7-4-8. Confirm that the installed flange matches.
Subaru Ej25 Flywheel Torque Pattern Diagram
| APPLICATION / ITEM | SPECIFICATION | NOTES |
|---|---|---|
| 2004 non-STI | 72 N-m / 52.8 lb-ft | Flywheel/drive plate |
| 2004 STI | 77 N-m / 56.8 lb-ft | Flywheel/drive plate |
| Pattern | 8-fastener opposite-side | Verify actual flange |
| Friction face | No oil/grease/coolant | Factory caution |
Subaru explicitly separates STI and non-STI torque branches in the cited model-year manual and warns against oil, grease or coolant on the clutch disc and flywheel.
How to use this specification correctly
- 01
Confirm the engine code, crankshaft/rear-seal generation, transmission type, flywheel or flexplate part number, balance specification and fastener part number. Photograph orientation marks before removal.
- 02
Disconnect the battery and support the engine and transmission with rated equipment. A flywheel is heavy and a thin flexplate has sharp edges; use eye protection and a flywheel holding tool rather than hands or a screwdriver jammed into the ring gear.
- 03
Remove the clutch/torque-converter fasteners and transmission according to the vehicle manual. Mark converter depth before separation and keep the converter fully seated in the transmission pump.
- 04
Inspect the crank flange, register, bolt holes, rear seal, pilot bearing, ring gear and both faces of the flywheel/flexplate. Reject cracks, heat checking beyond limits, elongated holes, damaged teeth or an unapproved resurfaced thickness.
- 05
Clean mating faces so the part seats metal-to-metal. Keep oil, grease and threadlocker off friction surfaces. Chase threads only if the service procedure permits it and blow blind holes clear without spraying solvent into the engine.
- 06
Install the correct reinforcement/drive-plate or flywheel stack in its documented direction, keeping the clutch face completely free of oil, grease and coolant.
- 07
Hand-start eight bolts, tighten using 1-5-2-6-3-7-4-8 stages and finish at 72 N-m non-STI or 77 N-m STI for the cited 2004 branch.
- 08
Install clutch, pressure plate or converter hardware only after the crank-flange joint is complete. Use alignment dowels and the separate pressure-plate/converter torque specification.
- 09
Measure flywheel/flexplate runout where the manual requires it and rotate the crankshaft by hand. Verify starter engagement, converter freedom/endplay and bellhousing alignment before final installation.
- 10
After startup, stop for scraping, cyclic knock or abnormal vibration. Recheck accessible converter/inspection-cover work only by the application procedure; do not casually retorque sealed crank bolts after operation.
Selecting the correct application branch
The cited manual assigns different T2 values to STI and non-STI cylinder-block illustrations. Choose by the exact model branch, not merely by the EJ25 family label.
Manual flywheel and automatic drive plate share the crank area but use different downstream hardware. Converter-to-drive-plate bolts in the same manual are a separate 25 N-m joint.
How the opposite-side sequence works
With 8 matching fasteners, the controller's physical labels are 1-5-2-6-3-7-4-8 around the circle. Tighten numerically so each step crosses or moves far from the previous position. Start every bolt by hand before the first staged pass.
Use several even preliminary passes when the source gives only a final torque, unless its instructions say otherwise. The final wrench pass must still follow the exact application sequence and calibrated range.
Installation procedure and verification
Install the correct reinforcement/drive-plate or flywheel stack in its documented direction, keeping the clutch face completely free of oil, grease and coolant.
Hand-start eight bolts, tighten using 1-5-2-6-3-7-4-8 stages and finish at 72 N-m non-STI or 77 N-m STI for the cited 2004 branch.
Mistakes that cause repeat failures
- Using STI torque on an unverified non-STI application
- Contaminating clutch friction surfaces
- Confusing converter bolts with crank bolts
- Mixing manual and automatic reinforcement parts
- Using an impact against an unsupported ring gear
Flywheel, flexplate and converter are separate joints
The crank bolts clamp the flywheel or flexplate to the crankshaft. Pressure-plate bolts clamp a clutch cover to a manual flywheel, while converter bolts connect an automatic flexplate to the torque converter. These fasteners commonly have different sizes, grades, thread treatments and torque values.
Never use the crank-flange torque for converter or pressure-plate bolts. Confirm converter seating before drawing the transmission to the engine; bellhousing bolts must not be used to force a gap closed.
Final installation checklist
- Correct balance and tooth count confirmed
- Orientation marks and crank register aligned
- New bolts/clamp ring used where required
- Mating faces clean and dry
- Specified thread treatment applied only to threads
- All bolts hand-started
- Staged opposite-side sequence completed
- Runout and pilot/bellhousing alignment checked
- Converter fully seated or clutch centered
- Engine rotates freely by hand
Subaru Subaru EJ25 DOHC specifications can change by model year, engine, platform, wheel, and installed component. Confirm the VIN or engine identity, part numbers, fastener condition, and the current manufacturer instructions before service.
Subaru EJ25 Flywheel Torque Pattern Diagram FAQs
What is 2004 Subaru EJ25 flywheel torque?+
The cited H4DOHC manual lists 72 N-m non-STI and 77 N-m STI.
Are converter bolts also 72 or 77 N-m?+
No. The cited manual separately specifies 25 N-m for torque-converter-to-drive-plate bolts.
Should flywheel bolts be tightened in a star pattern?+
Use the exact numbered factory figure when available. An opposite-side or crisscross staged pattern is the safe controller for a matching circular flange because it seats the part evenly.
Can flywheel bolts be reused?+
Only if the exact service manual and fastener instructions permit reuse. Torque-to-yield, coated single-use or damaged fasteners must be replaced.
Is flywheel bolt torque the same as converter bolt torque?+
No. They are separate joints with different fasteners and specifications.
Technical sources
TorqueSheet favors engine- and component-specific manufacturer instructions over unsourced universal values.
12004 Subaru Impreza H4DOHC engine mechanical manualThe Subaru factory-manual section identifies flywheel/drive-plate hardware at 72 N-m for non-STI and 77 N-m for STI applications in the cited model-year branch.↗