A340E Overhaul Kit

Owners searching for an A340E rebuild are usually dealing with a 4Runner that slips into overdrive on the highway, a Cressida that thumps into gear, or a Supra automatic that has started to flare between shifts. This A340E overhaul kit is a full master-style kit for that Aisin four-speed: it carries new friction plates and steel plates along with the gaskets, lip seals, O-rings, sealing rings and thrust washers needed to tear the unit down and put it back together tight. It is listed for 1989-2004 4Runner, 1988-1992 Cressida, 1988-1998 Supra and the 3.0 Crown, and cross-references the A340F four-wheel-drive version.

What the overhaul kit does in an A340E

The A340E is a computer-controlled four-speed: a three-speed Simpson gear train with an overdrive planetary in front, giving ratios of 2.804, 1.531, 1.000 and 0.705 with 2.393 reverse. Each ratio is applied by a hydraulic clutch or brake whose piston seals against its drum, and the friction plates in each pack take wear every shift. Over time the plates glaze or burn and the rubber seals harden, so line pressure leaks away before it clamps the pack. A seal-only kit fixes leaks but leaves worn frictions behind; this kit replaces both. The photo shows the friction and steel stacks, two valve body gaskets, the pan gasket, an extension housing gasket, three lip seals, six thrust washers and bagged O-rings and sealing rings.

Symptoms this kit addresses

• RPM flare on the 1-2 or 2-3 upshift, or slipping out of overdrive at cruise
• Slow engagement into Drive or Reverse, worst after sitting overnight
• Harsh or banging shifts as worn packs grab late
• Dark, burnt-smelling fluid with friction debris on the pan magnet
• Leaks from the pan, the front pump seal or the rear extension housing

How to confirm it before buying

Start with the fluid: check it hot at idle and look at its color and smell. Scan for stored transmission codes, because a failed shift or lock-up solenoid can mimic slipping and costs far less to fix. Then compare what you feel to the patterns in our Aisin harsh and delayed shift guide and the slipping under load guide. If the pan holds clutch material and the slip stays after a fluid and filter service, the packs are worn and an overhaul is the right repair.

Fitment

The listing covers the A340E and A340F in 1989-2004 4Runner (A340E in two-wheel drive, A340F in four-wheel drive), 1988-1992 Cressida, 1988-1998 Supra and the 3.0 Crown. Two cautions: the twin-turbo 2JZ-GTE Supra used a heavy-duty A340E with a different case and larger converter, and the A340 family changed its valve body around 2000 when the throttle cable was dropped for an electronic pressure solenoid. Clutch counts can differ between versions, so match your transmission tag and model code, or send us your year and VIN before ordering. More parts for this family are in our Aisin transmission collection, including the earlier A340E overhaul kit for 1985-2000.

Install notes

• Soak all new friction plates in fresh fluid for at least 30 minutes before stacking them.
• Install lip seals and O-rings lubricated, and use assembly gel to hold sealing rings and thrust washers in place.
• Measure each clutch pack clearance after assembly and air-check every piston before the valve body goes on.
• Fill with Toyota Type T-IV fluid; dry fill capacity is about 8.3 liters, so set the final level hot on the dipstick.
• No filter is shown in the kit. Fit a new one, and replace tired solenoids while the pan is off with the A340E shift and TCC solenoid kit with filter.
• Inspect the pump bushing and gears; a scored pump should be replaced with a new A340E oil pump assembly.

After the rebuild, follow the service intervals in our Toyota transmission service guide to keep the new frictions clean.

Does this kit include frictions and steels?

Yes. The kit includes friction plates and steel plates along with gaskets, lip seals, O-rings, sealing rings and thrust washers. It is a full overhaul kit, not just a gasket set.

Will it fit an A340F four-wheel-drive transmission?

The listing cross-references the A340F. The 4x4 version shares the main gear train, but confirm your transmission tag before ordering, especially on late units.

Does it fit a twin-turbo Supra?

The 2JZ-GTE twin-turbo Supra used a heavy-duty A340E with a different case. Send us the transmission tag or VIN so we can confirm before you order.

What fluid does the A340E use?

Toyota Type T-IV automatic transmission fluid. Dry fill is about 8.3 liters; check the final level hot at idle.

What else should I replace during the rebuild?

Install a new filter, inspect the pump and replace it if it is scored, and consider new shift and lock-up solenoids while the valve body is off.

• Aisin Harsh and Delayed Shifts
• Aisin Slipping Under Load: Root Causes and Fixes
• Toyota Camry and Tacoma Transmission Service
• Aisin Overheating: Why It Happens and How to Prevent It