Parts for your 2005 Toyota Bb-Oil seals

2005 Toyota bB oil seals: what they do and when to sort them

Based on Toyota’s own technical literature and parts data, oil seals absolutely apply to the 2005 Toyota bB. The Toyota Repair Manual for the NCP30/NCP31 series (Engine Mechanical – 1NZ‑FE/2NZ‑FE) and Automatic Transaxle sections (U340E), along with the Toyota Electronic Parts Catalogue, identify front and rear crankshaft oil seals, oil pump sealing, and transaxle drive shaft/output oil seals. Aisin’s U340E overhaul documentation also specifies the side (diff) and input/output shaft seals. So yes—this model uses a number of oil seals critical to keeping fluids where they belong.

On a 2005 bB, those seals keep engine oil and transmission fluid inside the engine and gearbox while keeping dust and water out. Typical spots include the crankshaft front seal behind the crank pulley, the rear main seal between engine and transmission, and the transaxle drive shaft seals where the CVs slide in. These little rings of rubberised material work under heat, pressure, and rotation—if they harden or wear, leaks show up.

Why they matter? Leaks can drop oil level, contaminate the clutch (if manual), soften rubber mounts, and make a real mess. Left long enough, low oil or ATF can damage the engine or gearbox. The bB’s 1NZ‑FE chain-driven engine doesn’t have a timing belt interval to trigger seal replacement by default, so seals are usually replaced reactively (at the first sign of seepage) or opportunistically during major work.

• Typical leak clues: oil mist around the crank pulley area, drips from the bellhousing, ATF weep at the inner CVs, burning‑oil whiff after a drive, or oily undertrays and driveway spots.

There’s no fixed kilometre interval, but by 150–200,000 km many originals are past their best. A workshop will confirm the source with UV dye or a careful clean-and-recheck.

1. Use quality seals (genuine or OEM) and inspect the shaft surface for grooves, polish or use a sleeve if needed.
2. Lightly oil the seal lip, press in square to the correct depth, and follow Toyota torque specs.
3. Check crankcase ventilation (PCV valve) so excess pressure doesn’t push new seals out.
4. For the U340E, replace drive shaft seals when the shafts are out and refill with the Toyota-specified ATF noted in the service manual or bonnet label (earlier cars often list Type T‑IV). For manuals, use the specified GL‑4 gear oil.

If a seal is sweating lightly, it may be watched for a bit, if it’s leaving drops, it’s time to book in. Keeping fluids topped to the mark and the underside clean helps spot issues early and keeps the bB happy on Aussie and Kiwi roads.

Popular questions

Does a 2005 Toyota bB have oil seals?
Yes. The bB uses engine crankshaft oil seals (front and rear), oil pump sealing, and transaxle drive shaft/output seals. This is confirmed in Toyota’s NCP30/NCP31 Repair Manual sections for Engine Mechanical and U340E automatic transaxle, plus the Toyota Electronic Parts Catalogue.

How much does a rear main seal replacement cost on a bB?
It’s labour‑intensive because the gearbox needs to come out. In Australia or New Zealand, expect roughly AUD/NZD $700–$1,500 depending on auto vs manual, workshop rates, and any extras (rear main housing gasket, flywheel/flexplate bolts, fluid, and mounts).

Is it safe to drive with a small oil seal leak?
Short term, possibly—if it’s just a light weep and fluid levels are kept spot on. But any active drip risks contaminating components and running fluid low, so it’s best to schedule a repair sooner rather than later.