RE5R05A Shift Kit

This is a new Superior shift kit for the Jatco/Nissan RE5R05A, the five-speed rear-drive automatic in the Nissan Titan, Frontier, Xterra, Pathfinder and Armada and the Infiniti QX56. It is built for owners and rebuilders who are tired of soft, slow upshifts, a flare between gears when towing, or clutch packs that come out burnt on the second rebuild. The box shown is Superior's Shift Technology line, marked TransLab Engineered, with replacement valves, springs and installation hardware.

What a shift kit does in an RE5R05A

The RE5R05A shifts entirely by solenoid. The control module commands the shift solenoids, but the oil those solenoids control still has to pass through regulator valves, pilot valves and accumulators in the valve body before it reaches a clutch or the front band. As the aluminum bores wear and the stock springs relax, apply pressure leaks off and each clutch takes longer to lock. That extra slip time is heat, and heat is what glazes frictions. A shift kit replaces selected valves and springs and recalibrates those circuits so the clutches apply quicker and with more holding force. It does not replace the solenoids or the computer; it changes how the hydraulics respond to them.

Pressure supply is the part most people overlook. Sonnax points out that pilot valve A on this unit feeds the line pressure modulating solenoid and the converter clutch solenoid, while pilot valve B feeds the clutch, band and brake solenoids. A worn pilot bore drops pressure to everything downstream, so a kit installed on a valve body with a leaking pilot bore will not deliver the firmer shift you paid for.

Symptoms this kit is meant to fix

• Soft, lazy upshifts that get worse under load or with a trailer behind the truck
• Engine flare between second and third or third and fourth
• Clutch packs burning up again after a previous rebuild
• Slow or soft engagement after the fluid is hot
• Shift quality that changes from day to day with no stored code

A shift kit is not a cure for a code-setting failure. Solenoid circuit codes, a stuck gear or limp mode point at a solenoid, the harness or the control module, not at calibration.

How to confirm before you buy

Start with the fluid. If it is milky or pink, the radiator cooler has failed and put coolant into the transmission; Sonnax reports roughly half of the RE5R05A cores they see have water intrusion, so fix the cooler first. Next scan for codes and check line pressure. Gears Magazine documented a 2007 Frontier that kept a harsh 1-2 shift through two new valve bodies; the real cause was worn sealing ring lands on the direct clutch support, measuring 0.018 inch clearance against a new ring. Shift problems that survive a valve body swap usually live in the hard parts. The RE5R05A transmission service guide walks through the fluid, code and pressure checks in order.

Fitment

The listing is for the RE5R05A in general, without a year range. That matters because Sonnax identifies three versions of the RE5R05A valve body: two with a pair of neutral-to-reverse accumulators (the second adds a reverse brake pressure control valve) and a third with one large accumulator, and they should not be mixed. Before you order, look at the lower body of your valve body and note which design you have, then compare it with the kit instructions. If you are not sure, send us your year and VIN and we will check it. Every part we carry for this transmission is on the RE5R05A collection page.

Install notes

• Install the kit during a rebuild or valve body service with the valve body on the bench, never as a pan-off job.
• Lay out each valve, spring and retainer in order as it comes out, and follow the kit sheet for which pieces are reused and which are replaced.
• Check both pilot valve bores for wear while the valve body is apart; a leaking bore defeats the kit.
• If the solenoids are original and high mileage, replace them at the same time with the RE5R05A solenoid kit.
• Fit a new filter and pan gasket; the RE5R05A filter and gasket kit covers it.
• Refill with Nissan Matic S ATF (Matic J is the approved alternative), clear codes and reset the adaptive values before the road test, then recheck the level hot.

If the valve body casting is too worn to rebuild, a complete RE5R05A valve body is the better starting point.

Which vehicles use the RE5R05A?

Nissan used it in the Titan, Frontier, Xterra, Pathfinder and Armada, and Infiniti in the QX56 and other rear-drive models. It debuted in 2002 in the Infiniti Q45.

Will this shift kit fit my valve body?

There are three RE5R05A valve body designs that differ in the neutral-to-reverse accumulators and the reverse brake pressure control valve. Identify yours and compare it with the kit instructions, or send us your year and VIN.

Can I install a shift kit without rebuilding the transmission?

It can go in during a valve body service, but if the clutches are already burnt the kit will not save them. Install it with new frictions or a rebuild kit when the old ones are worn.

Will a shift kit fix a solenoid code or limp mode?

No. Codes and limp mode point at a solenoid, harness or control module problem. A shift kit corrects hydraulic calibration, not electrical faults.

What fluid should I use after installing it?

Genuine Nissan Matic S ATF, with Matic J as the approved alternative. Reset the adaptive values and check the level at operating temperature.

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