Warning for those who are running Merc V and have an older M5od

[Simple_serf]

I was running mercon 5 in mine, because it was all the dealer could get. It started to shift like crap, and when the temp dropped here, I had to double clutch it. I just got some mercon and swapped it out. The difference is amazing. It shifts as perfectly as a trnas with 188K now!

My point?... Don't run Merc V unless your trans has it listed for it!!

I learned a good lesson.

 

[racsan]

im running pennzoil syncromesh in mine right now, its about the same viscosity as atf, have heard of some others using it, figured id give it a try, i have some minor trans issues anyhow (2nd gear engagement & downshifting into 4rth and 2nd) im sure it wont be a cure, but dont think it will harm it. if it does im just on my way quicker to my 3rd M5OD in this truck. i dont think this last one was done right, ive had the downshifting issues for awhile.
________
herbal store

 

[AllanD]

Another interesting one is running a 2003 gearbox with mercon3 in it.

The synchros on 2, 3 and 5th actually feel "Sticky" because they are friction faced synchro rings and are intended to "Grip" without having to "squeegee" the slightly
thicker Mercon3 out of the way

The think you'll ntice most is a pretty solid "chunk" into 3rd gear
on most upshifts, it'll always go in but you get a pretty solid thunk
each time.

AD

 

[Wicked_Sludge]

when i changed the fluid in my '93 to merc V i noticed quite an improvement in shift quality (much easier and smoother going into gears).

 

[racsan]

i think sometimes just having fresh fluid in general makes for better shifting.
________
vaporizer

 

[CopyKat]

try 5W30

 

[Bent Bolt]

Back when I had my Mustang in the early 90's, I ran 1/2 ATF and 1/2 10w30. Made a big improvement in shifting and noise. The fluid looked like crap , diarrhea to be specific.