P0730 on Subaru: How to Diagnose & Fix

The Lineartronic CVT (TR690) in 2014-2021 Foresters can develop shuddering, hesitation, and in severe cases, complete failure. Symptoms typically begin around 60,000-100,000 miles. The CVT chain can stretch, causing slippage and shudder during light acceleration. The torque converter can also develop issues. Subaru extended CVT warranty to 10 years/100,000 miles under Customer Satisfaction Program WTY-72. Multiple software updates have been released to address shifting behavior.

The Lineartronic CVT can develop shudder, hesitation, or jerky operation, especially during light acceleration at low speeds. Subaru has updated CVT software multiple times to address these concerns.

The Ascent's high-torque Lineartronic CVT (TR730 - the largest CVT Subaru has produced) paired with the 2.4L turbo FA24 engine exhibits hesitation from stops, harsh engagement when shifting from Park to Drive/Reverse, and surging at low speeds. The TR730 CVT must handle significantly more torque than Subaru's other CVTs, leading to durability concerns. Multiple TSBs have addressed calibration issues. Some owners report complete CVT failure under 60,000 miles.

The Ascent's TR730 high-torque CVT develops valve body failures that cause erratic shifting, harsh engagement, and transmission warning lights. The valve body controls hydraulic pressure to the CVT pulleys and chain, and when solenoids or passages within it fail, the transmission cannot maintain proper ratio control. This issue is distinct from the CVT hesitation TSB and represents a hardware failure rather than a calibration issue.

The Lineartronic CVT (TR690) used in Crosstreks develops chain stretch over time, typically between 80,000-130,000 miles. The stretched chain causes slippage, resulting in judder during light acceleration, particularly between 20-45 mph. The issue worsens in cold weather and uphill conditions. Subaru addressed earlier models under warranty extension WTY-72 (10 years/100,000 miles) and released multiple software calibration updates. In severe cases, the CVT requires complete replacement.

The clutch throw-out bearing (release bearing) commonly develops a chirping noise that goes away when the clutch pedal is pressed. This is a known issue on WRX models and while the noise is annoying, it doesn't always indicate imminent failure. However, it should be monitored.

The 2010+ Legacy uses the Lineartronic CVT (TR690 for 2.5L, TR580 for 2.5i base) which has widespread reports of premature failure, typically between 80,000-140,000 miles. Failures include chain stretch, torque converter shudder, valve body malfunction, and complete transmission failure. The 2010-2014 models are most affected. Subaru extended CVT warranty coverage to 10 years/100,000 miles. Symptoms often start with subtle judder during light acceleration and progress to complete loss of drive.

Manual transmission BRZs commonly develop throwout bearing (release bearing) noise, typically a chirping, squealing, or grinding sound when the clutch pedal is pressed or released. The noise is most apparent in cold weather and often appears between 20,000-60,000 miles. While the noise itself is mostly a nuisance, a failed throwout bearing can cause clutch disengagement problems. Subaru has not issued a recall, but the issue is well-documented across both BRZ and Toyota 86 communities. Replacement requires transmission removal.

The 2012+ Impreza's Lineartronic CVT (TR580 for 2.0L models) is prone to harsh engagement, delayed acceleration response, and premature failure. The smaller TR580 CVT handles the 2.0L engine but can develop valve body issues causing harsh shifts into Drive/Reverse and a pronounced thunk when engaging gear from Park. The CVT chain can stretch, and the transmission oil pump can fail. Subaru extended the CVT warranty to 10 years/100,000 miles on affected models.