For reference this is out of a 2015 Mazda 6. Different model number but also an Aisin gearbox (although based on the ZF6HP.) Thought you Lexus guys may find this useful. Mileage was right around 103,000 miles.

So you have a metal pan with a drain plug and a little spot in the corner for your magnet which catches metal shavings. Most of these accumulate when the transmission is new and during abusive driving. There is also this little box filter thing with tubes on either side which acts as a strainer/separator to keep the metal shavings at the bottom of the pan, separated from the solemoids and intricate passageways of the transmission ensuring it does not float around the unit.



Here's what it looked like when the pan was dropped. Its obviously dirty, but I don't think that looks too bad for the mileage. Note the black sludge stuff at the bottom of the pan. The fluid was dirty, although not horrible. It still seemed to have lubricational properties when I rubbed it on my finger and it did not smell burnt or anything, at least.

Here's a picture of the magnet. I poked at it a little in the bottom so you can get an idea of the build-up. The mechanic said it looks bad. At least she did her job though!

.... And here is the same magnet after giving her a good wipe. Going back into the new pan..

Here is the paper mesh filter box thingy. I should have taken a more zoomed out picture of this unit which sits above the pan, but I only got a picture of what the mesh looks like inside. Obviously it's very dirty inside, but she clearly did her job to protect this gearbox. Before putting the pan back on you must very carefully clean the mating surfaces of any fluid debris or old gasket paste and apply a new.paste to the surface of the new pan. She took 4L of ATF fluid inside. Maybe about a third of total capacity; most of which is inside the sealed torque converter. Youd need to do a few more drain and fills to fully circulate all the old fluid out, but as long as the magnet and filter is clean no need to worry. Do not reuse the original bolts holding the pan in place.

Shifts are more crisp now and I am noticing less lag from the torque converter before lockup, at low rpms.

 

Filter/Strainer as I like to refer to it as. Is this the first drop and fill? If so, and you have no intention of doing a atf flush (machine or via opening the return line) then drive for 100 miles, drop and fill x 2 and that transmission should be good for 100k more (unless of course these have some pattern of failure)

 

Please reread my first edited post for more information.

Yes, this is the first time the pan has been dropped. This specific gearbox does not have lines for a transmission cooler to be fitter (same lines used for a fluid flush) meaning this method is not possible. Only other option is a few drain and fills but as long as the filter and magnet are always kept clean I dont think its necessary.

 

Good stuff, as long as you have got some new fluid, strainer you`d be better then most folks who believe in the lifetime fluids nonsense

 

Couldn't agree more. Then you get the same folks wondering why their excellent quality transmission didnt make it past 150k.

 

As long as you regularly replace the filter and clean the magnet this sort of negates the need for any drain and fill. If you dont drop the pan you wont be able to remove the sludge at the bottom of the pan. Dropping the pan let's you drain more fluid.

However the torque converter is a sealed unit so you're not able to replace all the fluid in the unit (roughly 12L, you'll get maybe a third of that out by dropping the pan or draining.) But it's not a big deal as long as the filter/magnet is clean and ready to pick up the excess shavings. Even if the fluid is dirty unless it's really bad its still going to protect the trans just fine unless the magnet cant hold the excess shavings anymore which now means you got that crap circulating through the intricate passageways. This is why a drain and fill or flush is a bad idea at high mileage because these shavings will probably just break free.

 

Are you planning to do a follow up drain and fill ?