Subaru transmission drain plug warning — 22.9-ft/lbs

Subaru issues a warning about over tightening a Subaru transmission drain

Subaru has issued a warning not to use any power tools when removing or installing a transmission drain plug. If the drain plug is stuck on removal, use a rust penetrant and hand tools ONLY. Using power tools can crack the transmission case. During installation, use a handheld torque wrench to prevent stripping the drain plug threads and possibly cracking the transmission case. The warning is clear about not using any air or battery operated power tools to remove or replace a Subaru transmission drain plug.

In fact, Subaru tests show that over-torquing by as little as 15% can strip the threads. Once you start stripping the threads, they tear up and bunch up and then CRACK THE TRANSMISSION CASE. Yes, you read that correctly.

Here’s the correct procedure to install the drain plug

Clean old oil and debris off the plug. Install a new gasket. Start by hand, turning it clockwise. Once you feel resistance, use a socket and torque wrench.

DO NOT USE POWER TOOLS. Use a 3/8” drive calibrated torque wrench ONLY. Do not tighten without a torque wrench. Tighten the plug to 22.9-ft/lbs. That’s NOT a lot of torque. They aren’t kidding. You can easily crack the transmission case by over-torquing the drain plug.

Over torque a Subaru drain plug and this is what you get – a cracked transmission case