Parts for your 2004 Subaru Legacy-Driveshafts

2004 Subaru Legacy driveshafts

Based on technical sources including the Subaru Factory Service Manual (Driveline & Axle section), the Subaru global electronic parts catalogue, and workshop references like the Haynes manual for Legacy/Outback 2000–2009, the 2004 Subaru Legacy in Australia and New Zealand is all-wheel drive and fitted with multiple driveshafts: a left and right front CV axle, plus a two-piece propeller shaft to the rear differential. So yes—driveshafts are absolutely relevant to this model.

On this Legacy, the front CV shafts transfer torque from the transaxle to the front hubs, while the centre propeller shaft sends power to the rear diff to deliver Subaru’s signature Symmetrical AWD. Each shaft uses joints that allow for movement: constant-velocity (CV) joints up front and universal joints plus a centre support bearing on the prop shaft. Rubber boots keep grease in and grit out—if a boot splits, the joint won’t last long.

As part of routine servicing, it’s smart to inspect the driveshafts every service interval. Look for grease spray around the inner guards or underbody, cracked or thrown CV boots, torn clamps, and any play at the centre support bearing. On-road clues include:

• Clicking or popping on tight turns (outer CV wear)
• Vibration or shudder on acceleration (inner CV or prop shaft issues)
• Drumming or humming at 60–80 km/h that changes with throttle (centre bearing)
• Clunk on take-off or shift (worn U-joint or excessive driveline lash)

Replacement tips for a 2004 Legacy are straightforward but detail matters. Use quality shafts that match the vehicle’s ABS tone ring specification. If the inner CV uses a roll pin at the trans stub, drive it out carefully and fit a new one on reassembly. Always torque the axle nut to the factory spec and stake or secure as designed, fit new split pins where applicable. If there’s any sign of diff seal weep, replace the seals while you’re there. After front axle work, an alignment check is wise if the strut-to-knuckle fasteners were disturbed.

For the propeller shaft, note the flange orientations and maintain proper phasing when refitting. Many Subaru prop shafts have staked U-joints, meaning the practical service part is the complete shaft, though specialist driveline shops can often rebuild them. Renew the centre support bearing if noisy, torque flange bolts correctly, and road-test for smoothness. Keeping on top of boots and bearings will save dollars and keep the AWD system silky on Kiwi and Aussie roads.

Popular questions about 2004 Subaru Legacy driveshafts

Are all 2004 Subaru Legacys AWD and do they all have a propeller shaft?
In Australia and New Zealand, 2004 Legacy/Outback models are AWD and use a two-piece propeller shaft with a centre support bearing. While some overseas markets historically had FWD variants, the 2004 model years commonly sold here are AWD-equipped.

How long do the CV shafts and centre support bearing usually last?
With tidy servicing, many see 150,000–300,000 km. CV boots can fail earlier, especially with heat or off‑bitumen use, once a boot splits, the joint can wear quickly. A centre bearing can hum or drone as it ages—catching it early avoids damaging the rest of the shaft.

Can a clicking CV joint be saved with a new boot, or is a full shaft replacement needed?
If the boot is torn but the joint isn’t noisy and hasn’t run dry, a reboot and fresh grease can be fine. Once there’s clicking on turns or visible pitting, replacement of the complete shaft is the reliable fix.