Subaru Levorg STI: resealing a weeping TR690 CVT.

What came in

A 2019 Subaru Levorg STI, imported from Japan, with Subaru's TR690 CVT. The owner had found transmission fluid weeping from the CVT oil pump housing and got in touch in May.

They had already been to the Subaru network. By the owner's account, Subaru UK would not take the job on because their diagnostic system would not talk to the Japanese-market car.

The owner arrived well prepared. They had a copy of the Subaru service bulletin for the fault, and they had already bought the genuine Subaru sealant and the two O-rings the repair calls for.

What causes it

The bulletin is Subaru of America's 16-103-16R, "Transmission Fluid Seepage", first issued in December 2016 and last revised in October 2021. It names two likely sources for CVT fluid seeping from the gearbox:

• the sealant on the CVT's oil pump chain cover
• the input shaft oil seal

Subaru's fix is a clean, inspect and reseal of the chain cover, plus a new input shaft oil seal of a redesigned type. The new seal has an extra side lip whose job is to steer dust and water around the seal and away from the sealing surfaces.

The bulletin is written for the American model range: Legacy, Outback, Forester, Impreza, Crosstrek, WRX and Ascent. The Levorg is not on that list, but the procedure is written around the gearbox, and it has a section specifically for the TR690.

The parts

These are the part numbers the bulletin lists:

• ThreeBond 1215 sealant: SOA868V9600
• Ring seal: 31377AA510
• Ring seal: 806916060 (the two one-time-use O-rings on the converter case cover)
• Ring seal: 31377AA550 (one-time use)
• Oil seal: 806747030 (the input shaft seal)

What the job involves

This is a gearbox-out job: the bulletin's procedure starts by removing the CVT assembly. As a guide to the size of it, Subaru's own warranty time for removing, resealing and refitting the CVT on a 2015 to 2019 WRX is 4.0 hours.

The bulletin sets out the order of work:

1. Confirm it is CVT fluid. Before anything comes apart, check that the fluid is CVT fluid and not engine oil.
2. Remove the CVT and the torque converter. The torque converter comes off carefully, and the area around the oil pump chain cover is inspected for fluid and road dirt.
3. Check the converter case cover (TR690 only). If its mating face is wet, that cover comes off too: five 12 mm bolts, removed in a crossing pattern, and prised only on the tabs. Both one-time-use O-rings (806916060) are replaced. The front reduction drive gear shim has to stay with the cover. The O-ring 31377AA550 is renewed as well.
4. Remove the chain cover. On the TR690 it is held by seven 12 mm bolts. It is prised off in a set order, and only on the tabs, never on the machined sealing face.
5. Clean without damaging anything. All the old sealant is removed from both faces. The bulletin says no abrasive discs or gasket-removal wheels and no compressed air. Loose crumbs of sealant around the stator support are picked out with the sticky side of duct tape. Then both machined faces are checked for damage.
6. Renew the seals. The plastic sealing ring on the centre support is one-time use. It is replaced and lubricated with CVT fluid. The new input shaft seal gets CVT fluid on its main lip only. It is fitted flush with the edge of the cover, ideally with Subaru's installer tool 927890000. Pushed in too deep, it can restrict or block an oil passage.
7. Reseal and torque. A small bead of sealant goes along the edge of the chamfer, but not around one specific hole the bulletin marks. Too much sealant is a fault in itself. The TR690 cover uses two different bolt lengths, which have to go back in the right holes. Cover bolts and converter case bolts are torqued to 24 Nm in a crossing pattern.
8. Refit and road test. The torque converter and CVT go back in, and the car is road tested to confirm the repair.

Where it got to

The owner went away over the summer and came back to us at the end of August. The Levorg was booked in on 2 September 2026 for the CVT reseal, with an engine oil change and an MOT arranged during the same visit.

The O-rings. The two converter case cover O-rings (806916060) turned out to be hard to get hold of at short notice, and we spent time in September sourcing them.

Refitting the gearbox. By 16 September the reseal was done, the O-rings and the rest of the parts were in, and the CVT was back on the car. Then we found a problem. With the torque converter not yet bolted to the flexplate, the crank could hardly be turned by hand, and when it did move, the converter turned with the flexplate, as if the two were being squeezed together. That is not right, so the plan became to take the gearbox back off and inspect it rather than force anything.

The fluid. The TR690 in a Japanese-market Levorg STI is the high-torque version of the box, and it takes its own CVT fluid. The genuine Subaru fluid we were first supplied was not the right type for it, so it went back. Subaru's UK parts network did not stock the correct fluid, and nor did the motor factor we called. That meant a delay. We would rather wait for the fluid catalogued for this gearbox than fill a freshly resealed box with a near-enough substitute.

The chain cover. On 17 September, with the gearbox due to come back off, we also started sourcing an oil pump chain cover for the gearbox. The TR690 cover is held by seven bolts, so whatever we buy has to be confirmed as the TR690 part.

What to watch for on your Levorg or WRX

• Look for damp on the gearbox casing. The bulletin's photos show the seeping fluid running to a low point and out onto the converter case, so that is where it shows first.
• Find out which fluid it is first. Subaru's first step is to confirm the fluid is CVT fluid and not engine oil. The reseal does nothing for an engine oil leak.
• A Japanese-market car is not a reason to leave it. The reseal is mechanical work. If a dealer turns your import away, an independent who works to the bulletin can do the job.
• Use the fluid the gearbox was filled with. A Japanese-market high-torque TR690 takes a specific CVT fluid that UK parts counters may not carry. If it is not in stock, waiting for the right fluid beats a substitute.
• The seals are one use only. The O-rings and the centre support ring are not reused. If someone quotes the job without them, ask why.

If your Subaru is weeping fluid from the gearbox, our transmissions page and the Subaru specialist page are the places to start.