Just hit 180,000 miles and just recently started noticing some Mrmrmrmr when I push the pedal. I also have notice when I just go over some over passes that it kicks into a lower gear which it had never done before. That is when I realize I have not changed the tranny oil for a good while. At least 50k miles or more.

I have been searching for threads on a transmission filter replacements, but I am coming across so many thread that have to do with the transmission, but yet to find a good filter change thread for the 1st-Gen XB.

So my questions for a auto transmission of so many miles are:

1. A machine flush in which I read both the good and the bad and suspect that a normal pressure machine might do the job well compared to a high pressure.

2. Drain and replace the filter and at every so many hundred miles drain and refill until all the old oil is out

3. Toyota tranny oil, or synthetic? Can I drain and add synth to the existing oil and just re-drain after so many miles to drain out the old oil?

4. What about the differentials? Have not change that ether.

5. I viewed the filter earlier and it looked like a yellow fabric type screen. I have read it is a metal mess? I will take photos tomorrow morning.

 

I would change the fluid using standard gear oil. I used synthetic (redline mtf or something) and I eventually had a bearing failure. Rebuild = $1200 Not sure if the syn did it; but no one else I know had any issues and they all stuck with 90 weight gear oil (per Toyota recommendations).

Good luck and I hope the noise goes away!

**Edit** Realized that you have an auto-tranny. I would just do a drain/refill with filter change.