Toyo Koygo whine

[JMAT]

87 Ford Ranger with toyo 5 speed. Changed the fluid to hopefully get rid of annoying whine when accelerating. It whines in all gears except 4th and OD. Could someone please shed some light on the situation. Thank you.

 

[AndyB.]

What fluid did you use?

 

[JMAT]

75w90 synthetic

 

[cody93]

too think for that trans, tk-5's take mercon atf if i remeber, but i know gear oil is too thick for it.

 

[AndyB.]

Don't use ATF. I believe it takes 80w gear oil. I'm running redline mt 90 in mine. The bigger issue is that most multi weight gear oils come packaged with friction modifiers that will react, negatively, with the brass synchros.

Unfortunately, I have no ideas for you in regards to the whine.

 

[85_Ranger4x4]

Look in your book for sure on the oil.

I know the Mitsubishi's take 80-90 and the Mazda M5OD takes ATF but no idea on the TK.

 

[JMAT]

I searched around on a lot of forums and came to the conclusion of the gear oil. The fluid that came out was nasty. Shifts better with the new fluid but the whine is still present.