SUBARU 6-speed STI TY856 conversions

ADS brings premium power transfer TO WRX, forester and LIBERTY

If you’ve got a 5-speed Subaru WRX, Liberty or Forester, especially if you’re interested in using your car in competitive motorsport events, you’re probably aware that the five speed box, although serviceable and easy to use, is not the strongest or best Subaru gearbox around. You might also have heard of the race and rally successes enjoyed by the 6-speed WRX STI, with its quick, strong, close ratio gearbox, and you could be forgiven for feeling a twinge of envy. The 6-speed STI box was designed by Subaru with motorsport in mind. It is by far the best and strongest gearbox Subaru have ever made, and with the highest level of operability. The six-speed gear set is nearly twice the size of the 5-speed and twice as strong. It can easily handle up to 300 Kw of power and a high degree of driver abuse.

The six speed box (non-DCCD) was introduced in 2002 in the WRX STI, and revived interest in the Subaru brand. The STI still uses the 6-speed box, but since 2003, in DCCD version. Subaru are aware that in some ways this gearbox is the centrepiece of their premium performance models, and have invested considerable time and money into ongoing research and development. The six-speed DCCD gearbox has gone from strength to strength and has no known issues. The only problem is that this excellent gearbox only came in STI models, and if you wanted a super-strong competitive gearbox for your WRX, Forester GT/GX or Liberty GT, you had to turn to third party gear manufacturers.

Fortunately, it is relatively easy to retrofit the larger, stronger STI 6-speed gearbox to any of the 5-speed models, making it an ideal upgrade. However, there are some complicating internal factors, such as final drive ratios, and some DCCD issues. All Drive Subaru have spent considerable time researching solutions to these problems, and have come up with appropriate proprietary procedures and modifications to make the 6-speed gearbox work smoothly in your 5-speed model Subaru. The result is a kit to retrofit standard STI TY856 boxes to 5-speed models, using a fully remanufactured STI 6-speed, DCCD or non-DCCD, that will bolt straight into your WRX, Liberty GT or Forester GT/XT.

All these transmission numbers start with TY856. Subsequent numbers identify which specific components are in the box. All the specialist techs at All Drive Subaroo are up to date on all gearbox variants and understand the numbering system fully. Our comprehensive knowledge means that you can be sure that an ADS supplied gearbox will be fully compatible with your Subaru, and that it can also be custom built for your specific needs, with different ratios as required.

Beware of  Second hand conversions on the internet

All Drive Subaroo do not do conversions using second-hand boxes. There are a number of reasons for this. Six speed boxes from different models are not uniformly configured, raising the possibility of compatibility issues. Also, second hand boxes are an unknown quantity. If you are investing in a conversion of this nature, it usually means you want to keep the vehicle for a long time, and hope to get extended service out of the new gearbox. We stake our reputation on our reconditioned and remanufactured gearboxes.

There are several online sellers offering STI 6-speed conversions boxes using second-hand gearboxes and parts sourced either locally or from Japan. While these are certainly less expensive than our package kit, there are several pitfalls to look out for. For a start, you don’t really know what you’re getting; these might be high mileage boxes, despite claims to the contrary, and there may be other defects. For example, in our workshop, we see many 6-speed boxes that have worn hubs & sliders, synchros, and leaking seals. There are often issues with jumping out of fifth gear. In the end, a second hand box just might not give you good service and could prove to be a bad investment. There is also the strong possibility that the box, sourced from Japan or the US or Europe, will be incompatible with your Australian model, most commonly with speedometer readings, causing additional expense and stress. Also, when your second hand box needs repair it might be difficult to obtain compatible parts.


ADS HYBRID 6-speed conversion and fitting

ADS is the largest Subaru gearbox repair and remanufacturing center in Australia. We have the strongest knowledge base in Australia, and people in the industry routinely consult us on engine and transmission issues. All our gearbox packages have been completely disassembled and rebuilt using the latest revised parts and fixes for known inherent issues in the 6-speed box and come with warranty. Our kit takes all the worry out of the conversion. All the adaptions, modified tailshafts, and required parts are supplied ready to install with no further modification required.

If you’d rather have us do the fitting, you could bring your car to us, or we could organise for your vehicle to be delivered to our shop in Peakhurst. There are several advantages to having All Drive Subaroo do the installation, most importantly the warranty, with ADS covering both parts and labour. You also have the peace of mind of knowing that your gearbox has been built and installed by Australia’s leading independent Subaru-only workshop, with experienced gearbox specialists handling every phase of the project.

Our 6-speed conversions come in a fully tested drop-in kit with remanufactured transmission that includes the following parts:
  • A refurbished gearbox housing
  • New or Inspected gears 1-6
  • New shifting hubs and sleeves
  • New shift forks
  • New shift rods if required
  • New synchro cones
  • New and inspected bearings
  • Serviced front differential crown wheel and pinion
  • New or serviced viscous coupling
  • Full genuine Subaru gasket seal kit
  • Assembled by experienced ADS gearbox techs

ads offers two levels of 6-speed STI TY856 upgrade

“Hybrid 6MT” Includes Transmission and Driveline Kit

Drop-in, drive away

This kit includes only the fully assembled transmission and essential components. It’s suitable for the owner looking for a more durable and operationally engaging alternative to the standard five speed box. The driving experience alone makes the conversion worthwhile, and you have the security of knowing that this gearbox will not fail under high loads and will deliver reliable long term service. ADS have designed this kit to match straight up to your existing drive shafts for maximum convenience.

The 6 speed driveline conversion includes:
  • A complete overhauled STI 6-speed transmission (as noted above)
  • A matching R180 or R160 rear differential
  • Modified tail shaft assembly
  • 6-speed STI short shift shifter
  • Factory wiring and modified plugs
  • Starter motor unit
  • Subaru 6-speed or 5-speed performance clutch assembly
  • Matching cross member with mounts (if required)
  • Instructions and phone support for installation

The strongest quick-shifting mass produced Subaru gearbox ever made ready for your WRX Forester or Liberty without any modifications: drop in, drive away. This conversion will transform your driving experience.

“The Full Package” Includes Option 1 plus Suspension and Brake Kit

The ultimate upgrade

The Full Package is suitable for the enthusiast driver aiming for a high level of performance. In effect, it upgrades a standard WRX or Liberty GT to STi specs, except for the engine and trim. This delivers greatly enhanced road holding and braking capabilities and is an ideal upgrade for the enthusiast driver with a performance tuned Subaru

  • A complete overhauled STI 6-speed transmission
  • A matching R180 or R160 rear differential
  • Modified tail shaft assembly
  • 6-speed STI short shift shifter
  • Factory wiring and modified plugs
  • Starter motor unit
  • Subaru 6-speed or 5-speed performance clutch assembly
  • Matching cross member with mounts (if required)
  • 4X STI wheel hubs (optional new wheel bearings)
  • Brembo brake callipers and discs (optional new pads)
  • Front and rear STI drive shafts
  • Front and rear STI shocks (may vary between models)
    Instructions and phone support for installation
Also available, for the more serious enthusiast, add–ons and performance differential upgrades including:
  • “Suretrac” plated type limited slip differential
  • “Torsen” gear type limited differential
  • Front hemisphere (low and high-response plated differentials)
  • Centre viscous (mechanical lock type) differential
  • Centre viscous LSD (98Nm (10kgm/50rpm) differential
Facts about All Drive Subaroo STi 6-speed conversion gearboxes
  • Warranty is 12 months or 50 000km whichever comes first, with ADS fitment
  • All Drive Subaru gearboxes are assembled by a team of Subaru gearbox specialists
  • All gearboxes fully refurbished by Subaru gearbox specialists
  • The 6-speed STi box is stronger than any other stock Subaru gearbox
  • All Drive Subaroo reconditioned gearboxes have the lowest rate of failure in the industry.
  • All drive Subaroo usually have stock on hand

The next best thing to buying an STI. The quickest and most robust transmission in the Subaru range, plus STI suspension and brakes. Total motoring immersion.

  • Warranty Terms & Conditions

Send Your Enquiry

Services Subaru Gearbox Australia Offer

Exchange gearboxes in stock

We have more than 50 gearboxes for all models on hand in all configurations ready to ship or fit.

Gearbox installation center

We have a fully equipped service center and the best team of specialist gearbox installers in the business.

DIY gearbox kits

All you need to build your own. We can guide you through the process, and supply all parts.

Viscous replacment

Subaru five-speed non turbo models are susceptible to viscous coupling failure. We can assess replace, and upgrade.

New and used gearbox parts

We are an independent wholesaler of Subaru parts with a full inventory of all Subaru gearbox parts.

Motorsport gearboxes available

Straight cut, dogbox or helical competition gearboxes available.




Remember, the more specific details you can provide, the more accurate our response will be.


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