AW4 Shift Kit, new and ready to install. Fits the AW4. Ships fast from the USA.
A Jeep Cherokee XJ, Comanche or Wagoneer with the AW4 four-speed that slurs the 1-2 shift, feels lazy into third with a trailer behind it, or keeps cooking clutches after a rebuild is usually short on clutch apply rate, not on clutch material. This listing is the TransGo 340-HD2 Reprogramming Kit with Gear Command, the kit TransGo builds for the Aisin A340-family valve body that the AW4 shares with Toyota. It is new, made in the USA, carries a 1-year warranty and ships from the USA.
The AW4 is an Aisin-built four-speed with a Jeep-specific case and controls. The computer picks the gear through two shift solenoids, but how hard each clutch and brake applies is set hydraulically: line pressure follows a throttle cable through the throttle valve and primary regulator, and accumulator pistons for the overdrive clutch, direct clutch and second brake cushion each apply. The 340-HD2 kit recalibrates all three areas. It includes new pressure regulator springs and a washer, three cut back valve springs, short, medium and long accumulator spacers with new accumulator springs, a set of drill bits for opening separator plate feed holes, a hardened steel TCC relay boost valve and bushing to replace the soft aluminum original, and an optional hardened 1-2 shift valve with rivet that keeps the transmission in first when the lever is in manual low. That last piece is useful on the trail, where an AW4 normally upshifts out of 1 on its own.
A kit cannot fix a failed shift solenoid, a bad neutral safety switch or speed sensor, or clutches that are already worn through, all common AW4 faults. Rule those out first.
Check line pressure before you blame the hydraulics. The AW4 overhaul manual calls for a 300 psi gauge on the passenger-side test port. Spec is 53-61 psi at idle and 161-196 psi at wide open throttle in Drive, and 73-87 psi idle and 223-273 psi at WOT in Reverse. If it is off, adjust the throttle cable and retest. Our line pressure testing guide walks through the gauge hookup, and Aisin harsh or delayed shifts covers the other causes.
TransGo lists 340-HD2 for 1985-on A340, A341, A343 and AW4 transmissions, covering the 1987-2001 Cherokee XJ, the Comanche and the Wagoneer. The instructions cover four different valve body types with different solenoid layouts and bolt lengths, so identify yours before you start. Send us your year and VIN if you want us to confirm. Related parts are in our Aisin transmission collection.
| Fits | AW4 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Reference | A340E |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. The 1987-2001 Cherokee XJ automatic is the AW4, and TransGo lists the 340-HD2 for all AW4 units. Send us your VIN if you want it double-checked.
Yes. TransGo designs it as an in-vehicle install. You remove the valve body through the pan opening, modify it on the bench and reinstall it.
Plan on supplying gaskets that match your exact valve body. TransGo's instructions warn there are 17 different gaskets across these units and that you need the ones for your model.
With the optional 1-2 shift valve and rivet installed, the AW4 stays in first when the shifter is in 1, which helps on steep descents and slow trail work. Leave those parts out if you do not want it.
Not if the clutches are worn or line pressure is low from a pump or throttle cable problem. Do a line pressure test first; the kit improves apply rate on a healthy transmission.
That depends on the feed hole sizes you drill. TransGo gives separate truck and hot rod sizes and says to start with the small holes, which give firm but streetable shifts.
