Parts for your 2003 Toyota Bb-Thrust bearing

2003 Toyota bB thrust-bearing — is it actually fitted?

After checking Toyota’s technical literature for the bB NCP30/NCP31/NCP35 series and the Toyota Electronic Parts Catalogue, a “thrust-bearing” as a service part is not used on most 2003 Toyota bB models because the majority are fitted with the U340E 4‑speed automatic transaxle. In automatic variants there’s no clutch release mechanism, so there’s no clutch thrust/release bearing to replace.

Technical basis for this call-out:

• Toyota bB Repair Manual (NCP30 series): the Clutch (CL) section—and its release/thrust bearing—applies only to 5‑speed manual C5x models. The Automatic Transmission (AT) section shows a torque converter and no clutch release assembly.
• Toyota Electronic Parts Catalogue (EPC), model NCP30/NCP31: a “Release Bearing (Clutch)” is listed against C5x manual transmissions, it is not listed for U340E automatic variants.
• 1NZ‑FE Engine Mechanical: crankshaft thrust surfaces are integrated with the No. 3 main bearing set (thrust washers). These are internal engine components only addressed during overhaul, not a routine “thrust-bearing” service item.

Why it’s not used on most 2003 Toyota bB in Australia and New Zealand: the common JDM import spec is 1NZ‑FE with the U340E auto. An automatic uses a torque converter to couple the engine to the transaxle, so it does not need a clutch fork, pressure plate, or a release/thrust bearing. Any “thrust” control in the drivetrain is managed by internal washers and bushings within the transmission and the engine’s main bearing set—parts that aren’t replaced during normal servicing.

Own a rarer 5‑speed manual bB? Then the clutch release bearing (often casually called the thrust bearing) is relevant to you. If you hear a rumble only when the clutch pedal is pressed, that’s a classic sign the release bearing is tired. In that case, the correct search term is “clutch release bearing” for the bB/C5x gearbox, and it’s best replaced along with the clutch disc and pressure plate while the gearbox is out.

• Does a 2003 Toyota bB have a thrust-bearing?
  Yes for 5‑speed manual models (as the clutch release bearing), no for the common U340E automatic models.
• What should owners of automatic bB models check instead?
  For driveline noises on autos, look to the torque converter, flexplate, engine mounts, or wheel bearings—there’s no serviceable clutch thrust/release bearing present.
• Are there thrust bearings inside the engine?
  The 1NZ‑FE uses thrust faces at the No. 3 main bearing to control crankshaft end‑float. These aren’t routine service items and are only addressed during engine overhaul.

Popular questions about 2003 Toyota bB thrust-bearing

Does my 2003 Toyota bB use a thrust-bearing?
Most 2003 bB in Aus/NZ are automatics and don’t have a clutch thrust/release bearing. Manual C5x cars do, and Toyota’s EPC lists a clutch “Release Bearing” only for those manuals. The engine itself has thrust faces in the main bearings, but those are internal overhaul components, not a regular service part.

What are the symptoms of a bad thrust (release) bearing on a manual bB?
A growl or rumble when the clutch pedal is pressed, a notchier pedal feel, or difficulty selecting gears under load point to a worn release bearing. If the noise changes with the pedal position and disappears in neutral with the pedal up, the release bearing is a prime suspect. Replace it with the clutch kit while the gearbox is out to save repeat labour.

I’ve got an automatic bB—what might cause similar noises?
On autos, look beyond a clutch bearing. Common checks include the torque converter, flexplate cracks, auxiliary belt idlers, and front wheel bearings. Under‑bonnet noises that don’t change with clutch pedal movement (there isn’t one on autos) are a giveaway that it’s not a release bearing issue.