Overhaul, friction and steel kit for the Toyota A340E/A340F four-speed in the 1989-2004 4Runner, 1988-1998 Supra and Cressida, 2WD and 4WD.
This master kit is for owners and shops rebuilding the Toyota A340E or its four-wheel-drive twin, the A340F, in a 4Runner, Supra or Cressida. The usual reasons people search for one: a 4Runner that will not shift into overdrive on the highway, a Supra that flares on the 2-3 shift, or a truck that sits in neutral for a second or two on a cold morning before Drive engages. Once the fluid is dark and there is clutch material on the magnets, the answer is a full soft-parts rebuild. The kit combines three pieces: the overhaul set (seals, gaskets, sealing rings and rubber rings), a complete friction kit, and the steel plates.
The A340E is Toyota's rear-wheel-drive four-speed from Aisin, with a separate overdrive section in front of the main gearset. Its overdrive, forward, direct and second-coast packs, along with the brakes, are applied by pistons sealed with rubber lip seals, and the oil feeding them crosses rotating shafts through sealing rings. Over high mileage the frictions glaze, the seals harden and the ring grooves wear, so the pressure meant to clamp a pack leaks away. The result is the slow overdrive engagement and 2-3 flare these trucks are known for. The photo shows both valve body separator gaskets, the pan gasket, the extension housing gasket, front and rear seals, O-rings, sealing rings, plastic thrust washers, and a full set of frictions and steels. Every wear surface in the case gets replaced in one job.
Rule out the cheap causes first. Check the fluid level hot, scan for solenoid codes, and look at the solenoid connector and grounds; erratic shifts with clean fluid usually point to a solenoid or the valve body, not the clutches. If the fluid is burnt and the pan has friction material in it, the packs are done. The transmission slipping diagnosis guide walks through the order of tests, and Aisin harsh and delayed shifts covers the cold-engagement complaint in detail.
The listing covers the 1989-2004 4Runner with the 2.4L, 2.7L, 3.0L, 3.4L and 4.0L engines, the 1988-1998 Supra 3.0L, and the 1988-1992 Cressida, in both A340E (2WD) and A340F (4WD) form. Toyota changed the A340 over those years, and Sonnax documents separate valve body castings for 2000 and later units, so a 1990 and a 2002 unit are not identical inside. Match the tag on your case, compare the old plates and pan gasket to the new ones before assembly, and send us the year and VIN if anything looks different. More A340 parts are on our Aisin transmission parts page.
| Transmission | Toyota A340E / A340F 4-speed automatic |
| Fits | 1989-2004 4Runner 2.4L/2.7L/3.0L/3.4L/4.0L, 1988-1998 Supra 3.0L, 1988-1992 Cressida |
| Includes | Overhaul kit, friction plates, steel plates |
| Part number | Zun-A340E A340F |
| Weight | 7.5 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The kit is the overhaul seal and gasket set plus frictions and steels. Order a filter separately; the A340E shift and TCC solenoid kit with filter covers 2000-2004 units.
It fits the 2003-2004 4Runner with the 4.0L V6 and the A340E or A340F. The V8 4Runner of those years used a five-speed, so this kit does not fit it. Check your transmission tag or send us your VIN.
The A340F is the four-wheel-drive version and this kit is listed for both. The main extra job on the A340F is the transfer adapter seal. Compare plate counts to your old parts before assembly.
Toyota Type T-IV ATF. Soak the new frictions in it before assembly and refill with it after the rebuild.
A delay that goes away once the fluid warms up usually points to hardened piston seals. Low fluid can do the same thing, so check the level first. If the seals are the cause, this kit replaces them.
