89 2.3 What fluid for manual transmission?

[MaD]

On the door panel it has an M and the book says mercon. When looking around I can only find mercon V or LV. What should I use? Thanks!

 

[Shran]

Dex/Merc III is what you should use. It is readily available almost anywhere, usually just sold as “ATF” so read the label on the back and it should say compatible with Dex/Mercon II/III applications or something to that effect.

5w30 synthetic engine oil can also be used.

 

[RonD]

1989 2WD will have an M5OD-R1(M5R1) manual trans
Mercon V is spec, or synthetic equivalent
Holds 2.8 quarts but usually only takes about 2 quarts on drain and fill

 

[Shran]

I could be wrong but I was under the impression that Mercon V was specified for significantly newer M5ODs (like after '01 or so maybe?) and that others didn't like it in older transmission and felt that it caused shifting issues.

 

[racsan]

You can also use penzoil syncromesh fluid, Ive been running it for quite a few years now.

 

[MaD]

What about clutch fluid? What should I use?

 

[sgtsandman]

What about clutch fluid? What should I use?

DOT 3 brake fluid

 

[4x4junkie]

I could be wrong but I was under the impression that Mercon V was specified for significantly newer M5ODs (like after '01 or so maybe?) and that others didn't like it in older transmission and felt that it caused shifting issues.

You aren't wrong.

IMO, Mercon V shouldn't be used in ANY manual transmission made before 2008 (and I probably wouldn't use it in 2008-2011 trucks either even though Ford did spec it for those years).

Long story short, Ford wants Mercon V to be a "replacement" for Mercon (and so they pulled the licensing for the name "Mercon"). While it seems to be OK in automatics (such as the A4LD), I've seen negative impacts from it on manuals a number of times now, even personally (hard shifting, as well as making it difficult to put it into gear while stopped at a red light). My suspicion is that the additive package Mercon V uses is too slippery for the synchronizers in a manual to function correctly.

"Dex/Merc" is what you should get for any pre-2008 M5OD. It is manufactured to original Mercon specifications (and should say so on the bottle). It just cannot be called "Mercon" on the label anymore because of the license thing. It's available at most any auto parts store, and many gas stations (just not from Ford).