M5OD Fluid Recommendation
Thread Starter
|
Freshman User
Joined: Oct 2003
Posts: 30
Likes: 0
M5OD Fluid Recommendation
I have an 89’ F-150, 4x4 with a M5OD transmission. The truck has about 150,000 miles on it and is due for a transmission fluid change. The recommended fluid according to an aftermarket manual is Mercon II (ATF). I’ve heard of people using different mixtures of fluids to prevent synchro failure. Does anyone have any recommendations on what fluid(s) I should use?
BTW, it shifts ok but the tranny is noisy when the clutch is out. It also tends to pop out of second gear (potential synchro problem).
Thanks!
BTW, it shifts ok but the tranny is noisy when the clutch is out. It also tends to pop out of second gear (potential synchro problem).
Thanks!
Posting Guru
Joined: May 2002
Posts: 1,574
Likes: 1
From: Phoenix
hard to find mercon II but Dextron III/Mercon is compatible. Others have used a synthetic form but I've never tried it.
Here's a trick for this job. Drain it out the bottom, clean the magnet on the drain plug. and put it back in. Remove fill plug.
Inside the cab...remove stick shift off shift stub (pull off the nut on the stud under the rubber boot and put it on the other side of the stub and wrench untill the stud pops out. The stick then pulls off the stub. Maybe you already knew this.)
3 torx screws and the stub shaft cover and stub shaft come out. This is a good time to inspect the stub ball plastic bushings and replace if needed.
Now here's the cool part. You can pour the tranny fluid right into the top of the tranny. Fill untill it starts dripping out the fill hole underneath and then plug the fill hole right away. Button up the top and you're done. No need to pump the fluid into the fill hole and have fluid spill all over you and the floor.
Here's a trick for this job. Drain it out the bottom, clean the magnet on the drain plug. and put it back in. Remove fill plug.
Inside the cab...remove stick shift off shift stub (pull off the nut on the stud under the rubber boot and put it on the other side of the stub and wrench untill the stud pops out. The stick then pulls off the stub. Maybe you already knew this.)
3 torx screws and the stub shaft cover and stub shaft come out. This is a good time to inspect the stub ball plastic bushings and replace if needed.
Now here's the cool part. You can pour the tranny fluid right into the top of the tranny. Fill untill it starts dripping out the fill hole underneath and then plug the fill hole right away. Button up the top and you're done. No need to pump the fluid into the fill hole and have fluid spill all over you and the floor.
Posting Guru
Joined: Jan 2004
Posts: 1,232
Likes: 0
Popping out of gear is not a synchro problem, that is caused by the "clutch teeth" on the gear being rounded off. They are what the sleeve of the synchro slides over, which means the only way to fix that is to tear it apart and replace the actual gear. The noise while the clutch is out is either the input shaft bearing or the rear bearing. As far as fluid, make sure that it is ATF, either regular or a synthetic like Amsoil. I used full synthetic becuase in winter it is hard to shift gears until the engine warms the tranny up, so with synthetic I can cut down on the warm up time and make it a little easier to shift.
