Parts for your 2009 Subaru Legacy-Oil seals

2009 Subaru Legacy oil seals — what they do and when to replace them

Oil seals are absolutely used on the 2009 Subaru Legacy. This isn’t guesswork: the Subaru Factory Service Manual for the 2009 Legacy/Outback (BP/BL) and Subaru’s ANZ parts catalogue specify multiple oil seals throughout the engine, transmission and differentials. These include the front and rear crankshaft oil seals, camshaft oil seals, transmission input/output and selector seals, front differential/axle side seals, and rear differential pinion and side seals. If a 2009 Legacy has petrol and rotating shafts, it’s got oil seals keeping the fluids where they belong.

The purpose of these seals is simple but critical: keep engine or gear oil in, keep dust and water out, and maintain stable oil pressure. On the EJ-series 2.5-litre engines fitted to 2009 models, the crankshaft and camshaft seals ride on spinning shafts under the timing covers, while the gearbox and diffs use lip seals around axle stubs and shafts. When they harden or wear, owners see weeping around the timing covers, oil mist under the bonnet, a burning-oil whiff on hot days, or oily residue at the bellhousing or axle flanges.

• Common engine seals on this model: front crankshaft seal, rear main seal, and both camshaft seals.
• Driveline seals: manual and auto transmission input/output and selector seals, front diff/axle side seals, rear diff pinion and side seals.

Best practice is to replace the front crank and both camshaft seals during a timing belt service, as access is already open. Depending on market schedule, that’s typically around 100,000–160,000 kilometres or at the major belt interval. If oil has contacted the timing belt, replace the belt as well. For gearbox and diff seals, replace at the first sign of leakage and top up or renew the appropriate gear oil afterwards.

Good workshop habits help these seals live longer: ensure the PCV system isn’t blocked (excess crankcase pressure will push oil past good seals), inspect for nicks on the shaft sealing surfaces, and drive new seals square using the correct installer. Most Subaru lip seals are installed lightly oiled on the inner lip, the FSM will specify any exception. Avoid smearing RTV on the seal lip, use only the recommended non-hardening sealant on the outer diameter if the manual calls for it. After any seal job, clean down the area, road test, then re-check for weeps after a few hundred kilometres.

Popular questions about 2009 Subaru Legacy oil seals

How can someone tell which oil seal is leaking on a 2009 Legacy?
Start with a full degrease and a short drive, then inspect with a torch. Leaks at the front of the engine that track behind the crank pulley or timing covers point to a front crank or cam seal. Oil between engine and gearbox often indicates a rear main. Oily residue at axle stubs suggests diff or transmission side seals. If needed, a UV dye in the oil makes source tracing much easier.

Should cam and crank seals be replaced during a timing belt change?
It’s strongly recommended. Labour overlaps heavily, the parts are inexpensive, and fresh seals help protect the new belt. If there’s any sign of weeping—or the seals are original—most techs in Australia and New Zealand replace them proactively at the belt interval.

What sealant should be used on Subaru oil seals?
Generally, none on the sealing lip. Lightly oil the inner lip and install to the FSM-specified depth. Some seals may allow a thin smear of non-hardening sealant on the outer diameter, but only if the manual specifies it. The rear main on EJ engines is installed dry on the lip and square to depth—no RTV on the lip.