Magnetic Transmission Drain Plug

I prefer the widely available M18x1.5 aluminum magnetic oil drain plug with a 19mm hex head.

That way I will again have to deal with the 10mm Allen hex socket bit.

They are cheap enough that I use them for the transaxle fill and drain plugs as well as the inverter coolant drain plug.

 

What’s the thread dia/pitch?

^ Answered above by @Georgina Rudkus.

And the hex pocket, 10 mm (per stock)?

 

Just search Amazon for M18x1.5 magnetic oil drain plug and find the ones with a hex head.

If you prefer, they can also be had in stainless steel.

I like aluminum, because it is less likely to corrode when in contact with the cast aluminum transaxle case as well as the one on the inverter drain.

It is also less likely to corrode when in contact with the aluminum crush washers.

The steel plugs are a carryover from the days of steel transmission pans and cast iron diferential cases.

Toyota did not evidently want another part number to carry on inventories or the associated extra costs.

 

I prefer the ones with the 19mm hex head that will never strip out. I just use a 19mm socket, which I already have.

 

Contrary to the official Toyota service manual and conventional wisdom, the full engine undercover need not be removed to perform the transaxle fluid change.

Both the drain and fill plugs can be accessed through the opening of the oil change door which allows both plugs to be removed and reinstalled with the proper length socket extensions.

I also cut a hole in the engine undercover carefuĺy with a hole saw directly under the inverter coolant drain plug. This allowed removing and reinstalling the inverter drain plug without removing the engine cover at all.