cltchmoney

Motul gear 300 for diff and TC. I agree. Nothing special about Toyota WS. I am not an oil expert but I almost never stick to OEM oils down the road.

LexusGXFan

I find it interesting that Motul specs their Dual Clutch Fluid for the Lexus TC.

Are you running a 0w-20 or ?

cltchmoney

I saw that too on their website, not sure why. Plenty of FJ, 4runner and Prado owners using gear 300 in their tc. Yes 0w20 in the engine. Winter in Canada right now so average temp has been -1C or so and will get colder. May consider going to 5w30 in the summer!

william489

Hi Acrad,

What is purpose to do below step in your write-up, I do have an OBD fusion and I can get pan temp on my phone. I don't see any youtube video mention this step, guess I am missing something here.Thanks!

- Pinned open the AT thermostatic switch with a paper clip. A screwdriver to push in switch will be needed.

nuclearn8

I performed that step after my first drain and fill for the level check because I installed the oem tranny air cooler at the same time as the service and wanted to make sure tranny fluid circulated forward to those lines and I checked the level with the complete system in operation.

Acrad

This is my take/opinion on that step.

AT Fluid level is highly dependent on temp. Opening that thermostat (this is what controls fluid circulating through stock AT cooler inside radiator) ensures that all fluid in the system is at roughly the same temperature for a more accurate fill while doing the temp & drain check.

+1 to nuclearn8...I also wanted to ensure there was no chance lines were empty in any way after a drain.

nuclearn8

I performed that step after my first drain and fill for the level check because I installed the oem tranny air cooler at the same time as the service and wanted to make sure tranny fluid circulated forward to those lines and I checked the level with the complete system in operation.

william489

Thank you Acrad and nuclearn8. I can also leave the pin in-place without causing any harm post atf drain/fill?

https://www.tacomaworld.com/threads/...t-stat.682424/

I have an OBD fusion adaptor, I am going to use it for temp check. As for ATF thermal degradation (0 to 65536), I guess lower reading (below 50K) is better?

Acrad

I can only speak to my experience with leaving the pin in place. I haven't noticed any side effects. Lower would be better... you can reset that thermal degradation parameter with Techstream. That parameter came about with 14+. I don't have that option on my '12.

william489

I don't have external AT cooler installed or tow package for my 2015 premium. does it still make sense to leave the thermostat pin in place in hotter summer time?

My undertanding is if you leave the pin in place, it opens up the path to/from AT cooler (vs poppet valves only opens up at around 190/200F normally).

Thanks.

Acrad

IMO: I wouldn't worry about leaving pinned if you have not installed an external air cooler.

nuclearn8

You should read the OEM tranny cooler thread. Lots of good discussion there on the topic. Check the maintenance mods sticky, its linked there.

Leaving the tranny warmer pinned open is a personal preference. If I were to ever pin it open it would be during the summer months and/or extended towing, but thats my personal preference with the OEM air tranny cooler added.

william489

Thank you nuclearn8 and acrad. I pulled AT thermal degradation est this morning from obd fusion, I was dismayed to learn that my 2015 (73K miles) has reached 65535 max, which is a clear evidence to say AT fuild is not life time and shall be changed probably at 50K to be on the safe side. I don't tow and do any off road and I very seldom do any city driving.

nuclearn8

That increments each time the ignition is turned on... it's not necessarily an indication of transmission fluid condition... I haven't seen evidence its tied to temperature while driving and monitoring it... it doesn't increment at all that I've seen based on temperature all thr way up to normal operating temperature, but each time I start the vehicle it increments.
draining an filling the transmission is an extremely worthwhile service and high value if DIY.. like changing engine oil once you do it once.... simple.

Acrad

Not sure what formula is. I did come across a post on Tundra forum in past (still searching for link) where owner towing in high heat found the number rapidly increasing.