REVERSED AWD to 2WD SUBARU AUTOMATIC TRANSMISSION KIT
What’s in the kit?
Subaplate back cover plate with integrated Vanagon mount pad (fits Vanagon auto cotton reel mount) or Bay Window mount pad and mount
1 pair of Subasprockets (Main shaft sprocket with parking pawls and Pinion shaft sprocket) (not in Mid engine kit)
1 HYVO high speed chain (not in mid engine kit)
Subacover AWD clutch solenoid passage cover & load resistor
1 pair Subaflanges
1 pair Stub axle seals
1 pinion gear removal tool
1 pair Subastub axles if you have the NEW style 1 piece stub axle/cv joint. Not needed for the older style.
The Subaru automatic transmission has pop-in pop-out stub axles and spring clips. These are either held to your CV joint with a spring pin (old style) or a 1 piece stub axle and cv joint (new style). They may have been left connected to your axles when the transmission was removed from the donor car.
Old style : New Style :
Please inspect the style of seal you have installed on your transmission and measure the size of the inner seal hole to double-check.
Why doesn’t it include a reversed ring and pinion like the other kits?
The Subaru automatic transmission pinion shaft is located to the side, unlike the central pinion in the manual transmissions. This means we cannot flip the differential as there is no room in the casing. So we spin the differential in reverse instead. This is achieved by replacing the stock gears in the back of the transmission with a pair of sprockets and a special HYVO chain.
Will running the differential in reverse, on the ‘wrong side of the gear teeth’ make it weak?
Our 5 speed and 6 speed manual conversions have run on the ‘wrong side’ of the gear teeth for 10 years. They have not shown significant weakness or wear from running in reverse over this time. We have tested the reversed auto kit in our own cars for over 12 months and approximately 20,000 kms and have not seen increased wear.
Which Subaru automatic transmission will it work on?
Subaru 4EAT Series 2 with MPT transfer clutch
How do I recognise these?
Serial number TZ1A….or TZ1B. on the bellhousing near the starter motor. The 4EAT series 2 has a spin on oil filter on the side of the transmission.
Donor cars are approximately 1999-2006 (depending on your location).
The difference in the MPT transfer housing and VTD transfer housing is shown :
What will I need from the donor car?
The Subaru transmission computer and wiring harness, including the dropping resistor.
If you are installing the 4EAT into a car that is originally a manual car, you will need the Subaru gear shifter and cables.
The 4EAT TCU (transmission control unit) requires a number of wires & signals to work correctly :
From the engine computer (ECU) to TCU :
1) Throttle position sensor
2) RPM signal (6 cylinder or 4 cylinder – matched to engine & TCU e.g. if the TCU is from a 4 cylinder engine & trans donor, it will expect a 4 cylinder pulse from a 4 cylinder ECU).
From the TCU to ECU :
1) Speed signal
2) Torque cut on shift
From the general wiring harness :
1) Dropping resistor (if applicable)
2) 12 volts +
3) 12 volts –
It is possible to connect an older EJ22 engine ECU to a 4EAT series 2 transmission (TZ1A) and have them work together.
What cars will it fit?
The VW Vanagon / T25, late Bay window T2 bus (not lowlight).
What other items will I need to fit it into the VW?
VW late bay kombi : Nothing
VW Vanagon : 2 x LHS Vanagon automatic axles (520mm / 20.5 inches). Part number is 90-6804
VW Automatic vanagon cotton reel transmission mount (you should already have this). Trasnmission plate is 110mm from face to end and 40mm from inside mount plate to outside of mount face on the starter motor side of transmission.
Remote oil cooler, hoses and fittings for the transmission
What tools will I need?
A bearing puller with the fingers modified to reach behind the transmission gears
Access to a bearing press
What are the dimensions?
The reversed 2WD Subaru 4EAT is 655mm from end to end. 490mm from small end to centre of stub axles and 165mm from centre of stub axles to bellhousing face.
For reference, a Subaru EG33 H6 is 610mm length, a Subaru EZ 30/36 is 445mm, a Subaru EJ is 420mm.
VW cotton reel mount simply bolts to the Subarugears front trans plate.
Transmission is mounted as far forward as possible to the Vanagon firewall.
Mounting engine with VW “moustache bar” in our test Vanagon – the front mount bolt is moved to the factory rear bolt hole and a new rear bolt hole is drilled through the pinch weld.
On the test vanagon we installed a 25mm square steel spacer block to move the “Moustache bar” downwards.
Reversed Automatic conversion video
Now includes the Subatool auto pinion gear remover instead of using the 2 leg modified gear puller:
First startup of Subaru EJ25 and reversed 4EAT auto (it fits in there so well!)
Testing in regular traffic
Testing in freeway traffic
100kph at 2800rpm
Underneath the Vanagon 4EAT auto after 3,500kms of testing
Auto trans Vanagon integrated front mount
Testing out towing ability with a 2,100 kg 18 foot boat and trailer behind the auto vanagon :