RE5R05A Input Drum 2003-2005

If you are rebuilding the 5-speed automatic out of a 2003-2005 Nissan 350Z or Infiniti G35 and found a scored drum, a chewed-up shaft spline or burnt clutch debris welded into a housing, this is the assembly you are looking for. It is a used, original-equipment RE5R05A input shaft and drum stack pulled from a 2003-2005 Z33/V35-platform car, sold as the group shown in the photos: the splined input shaft, its toothed hub, and the stacked clutch drums and planetary section that ride on it. It carries a 1-year warranty and replaces the hard parts that a friction kit alone cannot fix.

What the input drum stack does in a 2003-2005 RE5R05A

The RE5R05A first went into production in 2002 behind the Infiniti Q45 and spread quickly through the rear-drive Nissan and Infiniti lineup, so the 350Z and G35 got it early in its life. Engine torque comes in through the converter to the input shaft, and from there the rotating drums carry it into the clutch packs and planetary gearsets that build each of the five ratios. Every rotating clutch in this stack is applied by fluid that has to cross from the stationary case into a spinning drum, and it does that through sealing rings riding in steel ring lands. When a drum cracks, its piston bore scores, or the ring lands wear, apply pressure bleeds away and the clutch it feeds slips, flares or engages harshly. A Gears Magazine case study on this unit traced a repeat harsh 1-2 shift to exactly that: the direct clutch, which applies on the 1-2 shift, was losing pressure past worn ring lands even though the clutches themselves looked fine.

Symptoms that point to the drum stack

• Slipping or flare in the specific gears one drum serves, while other gears feel normal
• A harsh or inconsistent 1-2 shift that returns after valve body or solenoid work
• Delayed engagement that gets worse once the fluid is fully hot
• Metal flake, aluminum shavings or friction material in the pan and filter
• Cracked drum fingers, spline damage or a heat-blued housing found on teardown

How to confirm before you buy

A drum stack is a teardown purchase, so start with the cheap checks. Pull the pan and look at the debris, check fluid level and condition, and rule out a solenoid or valve body fault with a scan tool first. Our RE5R05A service guide covers the fluid check and the common failures on this unit. Once the transmission is apart, air check each clutch circuit with regulated shop air no higher than 50 psi, and measure sealing ring fit in the lands. The Gears Magazine article found a top ring land at 0.018 inch clearance against a new ring where about 0.005 inch is expected, a step-wear pattern that is hard to see without magnifying a photo. If a drum, its bore or its ring lands are damaged, replace the hard part.

Fitment

This stack is listed for 2003-2005 Nissan 350Z and Infiniti G35 models with the RE5R05A automatic. The RE5R05A was built in several revisions across many Nissan and Infiniti vehicles, and the truck and SUV versions are not automatically interchangeable with the early car units, so compare the drums, shaft length and spline count against your own parts before reassembly, or send us your year and VIN and we will check it. Browse every RE5R05A part we carry on the RE5R05A collection page.

Install notes

• This is a used assembly: inspect bushings, thrust washers and sealing surfaces, and fit new sealing rings rather than reusing the old ones.
• Install new frictions and steels and new piston seals; a RE5R05A master rebuild kit covers the soft parts. Soak new frictions in fluid before assembly and set clutch clearances to spec.
• Air check every circuit at 50 psi maximum after assembly, before the valve body goes on.
• Install a new RE5R05A filter and pan gasket kit. If the old unit made metal, check the front pump too.
• Flush or replace the cooler. Sonnax reports that roughly half the RE5R05A cores it sees have water damage from a failed radiator cooler, and debris left in the lines will go straight back into the new parts.
• Fill with the Nissan ATF your owner's manual specifies, then clear codes and let the control module relearn shifts on a long drive that reaches full operating temperature.

Will this fit my 2003-2005 Nissan 350Z or Infiniti G35 automatic?

It is listed for 2003-2005 350Z and G35 models with the 5-speed RE5R05A automatic. Because the RE5R05A was used in many vehicles with different revisions, compare shaft length, splines and drums against your own parts, or send your year and VIN and we will confirm before it ships.

Does it include new clutches and seals?

No. This is the used input shaft and drum stack shown in the photos. Plan on new frictions, steels, piston seals and sealing rings from a rebuild kit during installation.

My 350Z has a harsh 1-2 shift. Is the drum the problem?

It can be. The direct clutch applies on the 1-2 shift, and worn sealing ring lands can bleed off its apply pressure even with good clutches. Rule out fluid level, codes and the valve body first, then air check and measure ring clearance on teardown.

What fluid should I use after installation?

Use the Nissan ATF specified in your owner's manual for your model year. Do not mix in universal fluids, and recheck the level hot after the first drive.

Do I need to do anything after installing it?

Clear codes and let the transmission relearn its shifts. Drive long enough to reach full operating temperature, since a cold unit runs higher pressure and can hide a sealing problem until it warms up.

• Nissan/Infiniti RE5R05A Transmission Service Guide: Pathfinder, Armada, QX56