Subaru SVX
There have been some important upgrades to the Subaru SVX transaxle. Listed below are descriptions of the critical ones.
1. The transmission oil pump gasket was changed to a beaded metal design because of a deterioration problem with the previous design. All SVXs with a manufacture date of 11/92 or a transmission I.D. # 513102 and after should have come with this redesigned gasket. It should also be mentioned that all transmissions with I.D. # 426208 and after came with a modified case which was the initial attempt to correct the pump gasket problem. Symptoms associated with a deteriorating gasket are approximately 1/2 main line pressure at idle, but full line pressure at stall speed. A delay going into reverse may also be experienced on SVX and Turbo vehicles. Oil pump installed to front of transmission casing.
2. A number of modifications have been made to the high clutch drum and related components. Some of the design changes were included in transmissions with I.D. # 463970 and after, with the rest showing up in transmissions with I.D. # 633658 and after. Some of the modifications were done to supply adequate oil flow to components for cooling purposes. Others to increase the friction surface area of the reverse clutch pack. The components are a newly designed high clutch drum, high clutch hub and bearings, reverse clutch fiber and steel plates and reverse clutch backing plate.
3. To reduce rear axle binding, the transfer clutch plates were modified around Oct. of 1992 and were installed on all production transmissions numbered 389607 and later. The transfer clutch kit previously included only the driven plates. The latest kit includes both the fiber and steel plates.
4. The Oil Sealing Rings located on the transfer clutch output shaft were redesigned because the previous design rings were grooving the extension housing. No clear information as to when or if these rings were installed during production.
5. The solenoid pack, located on the valve body of the transmission, includes a line pressure control solenoid. If the transmission has more than 50,000 miles on it at the time of repair, the solenoid pack should be replaced. The line pressure control solenoid is pulsed on and off many times during the life of the transmission and has been known to fail early, mechanically. The resulting symptoms are long, sliding shifts which quickly leads to burnt friction elements (band and clutch fiber plates).
6. The torque converter clutch lining can flake and plug the transmission cooler in the radiator, resulting in a loss of proper lubrication flow. The planetary gear sets suffer for it. Actually, I should say they melt down. It is recommended that an inline filter be installed and changed at regular intervals to prevent this clutch material, or anything else, from plugging the cooler. Subaru has a filter kit available at a very reasonable price, or you can install one of the aftermarket inline filters. 1993-97 SVXs came with factory installed inline filters and TSB # 16-56-93 came out and told dealerships to install filter kits to all 1992 model SVXs up to VIN # NH106285. Any 1992 SVX with a VIN number NH106286-108731 received just a new hose kit that prevented the hoses from leaking. The inline filter was not recommended for these cars for some unexplained reason.
7. A smart option available to the owner to help avoid the possibility of a lubrication type failure associated with a plugged transmission cooler, is to install an auxiliary cooler in parallel with the existing cooler already located in the radiator. The best place to install the auxiliary cooler is between the radiator and the air conditioning condenser.
8. If, during an overhaul of the 4EAT, it is determined that the forward sprag element needs to be replaced, you may need to update the forward clutch housing. The sprag size was updated and the forward clutch drum was changed to accommodate the larger diameter sprag.
Picture of the differential carrier installed in the final drive casing.
DRW Transmission Specialties, Inc. 10728 Kenney St. Ste. B, Santee, CA 92071
Office phone: (619) 258-4240 Fax: (619) 258-9105
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