Overdrive, transmission issues

[JohnMed]

I have also noticed that if it "cools down" it goes back to normal. What's up with that?!

 

[Patassa]

I'd do full 12 qt flush with Mobil 1 ATF in 98-02 100 series. If 03 Toy IV, if 04- up Toy WS ATF.
But first, I'd also monitor engine coolant temp and AT temp. Than again after full 12qt flush.

Can the Mobile 1 ATF be mixed with the toyota AT fluid if I want to do partial drain/refill over time?

 

[JGUL82]

Hey, did you manage to identify the issue. I have a similar issue with my LC100 2006 model. 4th gear doest engage

Did you ever figure out your issue ?

 

[2001LC]

Can the Mobile 1 ATF be mixed with the toyota AT fluid if I want to do partial drain/refill over time?

label says yes.

But I do only full 12qt flushes and never mix fluid.

Who knows what be added over the years.