Amsoil ATF in transmission

Where did you read that? It replaced T-IV in 2005 which was also synthetic.

 

toyota ws fluid is semi-synthetic

 

No, it has some minerals, but its definitely a synthetic. There is no literature that supports your claim.

 

every source i've found says that WS is only a semi-synthetic. that's why a lot of people use the Idemitsu fluid because it's a full syn.

just did my first drain and fill after 14k miles and it was dark brown. really like the idemitsu stuff.

https://www.idemitsulubricants.com/product/atf-type-tls-lv

 

Just ordered 5 quarts of AMSOil Signature Series along with OEM transmission gasket, filter l, & two washers.

I know that my 2006 Tacoma Prerunner with (168,000 miles) was last serviced at the Dealership and will have the Toyota Genuine WS in it.

Im planing to do a Drain & Fill with the same AMSOil (approx 3qts) three more times in 1 week intervals to ultimate have close to all AMSOil.

The reason I’m doing it this way is because I was told that a complete flush can potentially be harmful since the metallic particles of the gears can be flushed into areas that the should be in the first as opposed to downward to the pan.

Can any confirm they have done this?

 

When I switched to Amsoil I dropped the pan and replaced the trans filter (220k miles), then used the trans cooler lines (after the intercooler) to pull a quart at a time, replacing a quart at a time of Amsoil into the fill port. When Amsoil came out of the far side of the coolant line I topped off the fill port to make sure I had a full quart additional over the total removed so I could drain to final full volume.

35 or 45k miles previously I had done a full change (using the trans cooler lines) with Toyota WS, so I knew it was full (or full enough), and the total removed during the filter/amsoil change was very close to the specified capacity of the trans. I'm not concerned about the small amount of WS that is mixed in.