[Chucksta]

Non SVX related, or non Subaru? If it's not a 3.54 ratio, it was never in an SVX. There are a few reasons to ditch the factory transmission.

Increased accelleration. A 4.44 ratio swap would wake it up off the line, at the expense of higher RPM at highway speeds.

Increased reliability. Early SVX transmissions suffered from a few common ailments. "first gen" spewed friction material as a normal function of use. Unfortunately, Subaru put a small screen filter in the transmission pan. It plugged, the transmission lost fluid flow, and Cherynobled. The gearing itself causes high loading stress on it's bearings and also contributes to a high heat load on the transmission. There was a TSB ( Technical Service Bulletin ), which is like a recall, but not quite, to install a separate filter.

Price and availability. There were only about 25,000 SVXs' sold world wide, with only about 15,000 or so sold in North America. The ones sold outside of north America are different, and, although they can be used, are not "bolt in", they can be used, but it's a bit more involved. Other, more or less "bolt in" Subaru transmissions, of differing gear ratios, and the rear end "bits" to make them work, were produced for the North American market in the hundreds of thousands. Hence, cheaper to source and rebuild. A 3.54 SVX transmission, rebuilt and installed by a Subaru dealership can easily top three thousand dollars. A different, fully compatible transmission from a different Subaru product, is significantly less. If you're even a semi - competent mechanic, it's not that hard a DIY.. And the instructions can easily be found here on this forum.

If you want, you CAN use a Nissan Pathfinder transmission.. Oh... wait a second... Isn't that where a 4.44 comes from anyways? It's a 4EAT.. different gear ratios, some different internal bits etc.. but it's basically the same transmission.

One specific thing about the SVX is that, for lack of better terminology, the SVXs' engine and transmission are a team. They talk to each other in their own language. The TCU ( Transmission Control Unit ) and the ECU ( Engine Control Unit ) The "E" in "4EAT stands for "Electronic". It's not an old school transmission that relies solely on mechanical input for shift points, kick down etc. The kind of electronics that the SVX incorporates into it's drive train management is why there's such a thing as "Power Mode". In an SVX, the TPS ( Throttle Position Sensor ) MUST be properly calibrated to .50 volts. As little as a .20 volt variance will cause severe malfunctioning.

To install a transmission that doesn't speak "SVX", in and of itself would be problematic. To make it function properly would be it's own issue.


I'd like to ask, what is it about all the non stock, other than 3.54 options that are available from other Subaru products, or the Nissan transmission, that are unacceptable? What function is it that you are looking for that you can't find?