What fluid for a M50D?

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mikulh
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What fluid for a M50D?

Post #1 by mikulh » Fri Jan 07, 2011 4:46 pm

Hey guys. I was thinking it's about time to change the fluid in my M50D in my '91 F150.
I know that some modern 5 speeds use ATF instead of 90w gear oil. What does my M5OD use and how many quarts will I need to refill it?

thanks,
Michael

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StrangeRanger
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Re: What fluid for a M50D?

Post #2 by StrangeRanger » Fri Jan 07, 2011 5:09 pm

Mercon ATF or better yet synthetic Mercon for better lubrication resulting in less friction, cooler running and less power loss. Royal Purple Synchromax is a high tech lube designed for use in manual trannies that specify ATF. Whatever you use the capacity is 7.6 pints (3.55 litres)
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

mikulh
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Re: What fluid for a M50D?

Post #3 by mikulh » Fri Jan 07, 2011 5:40 pm

Thanks StrangeRanger!

93fordguy
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Re: What fluid for a M50D?

Post #4 by 93fordguy » Mon Jul 18, 2011 9:47 am

The owner at the transmission shop where I bought my tranny reccomended mobile 1 5W30 synthetic for my M5OD. I've been using that since it was new. I don't know how right he was about it but I've not had any problems yet. Maybe he was just looking for a "repeat customer." :?:

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StrangeRanger
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Re: What fluid for a M50D?

Post #5 by StrangeRanger » Mon Jul 18, 2011 11:02 am

He and Ford disagree as to the proper lube.
FWIW nearly everything inside an engine is in sliding contact and nearly everything inside a tranny is in rolling contact. This may add up to some subtle differences in lubricant properties.
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

Ferris Bueller
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Re: What fluid for a M50D?

Post #6 by Ferris Bueller » Wed Jan 11, 2012 2:11 am

Another thing with these Mazda built F150 and Ranger trannys is they leak. On many F150 and Ranger forums they think its the plastic plugs in the top of the tranny behind where the shifter attaches. In my experience its the tailshaft seal. Look for oily spray on the underside of the truck bed that starts even with the end of the transmission. The seal for my 04 Ranger cost $35 and took about 1/2 hour to replace.
White 09 Ranger 2wd 2.3 5sp 143hp 3.73 60k miles
White 04 Ranger 2wd 2.3 5sp 143hp 3.73 134k miles

sthorvictor
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Re: What fluid for a M50D?

Post #7 by sthorvictor » Thu Feb 19, 2015 8:17 pm

(mod, sorry I didn't realize how old this thread was)
mine was recently leaking from the top cover too^ :wink: nothing some ford grey silicone cant fix haha. anyhow the rubber shift rod plugs (at the front and rear of the top cover) shrink over time and thus leak. another thought to add about the atf in the m50d, is the friction modifiers in the fluid that helps the poor syncros out. helps them grab and prevent premature wear, beats hard/sticky/grinding shifts.
Best of luck,

Seth

turbocharged maf 300 f150

crackdhead
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Re: What fluid for a M50D?

Post #8 by crackdhead » Sat Feb 21, 2015 11:28 am

My rubber plugs in the shifter cover were leaking also (arent they there to cover the shifter rail holes?) I put metal freeze out plugs in them... Left the trans together and took the floor plate out then proceeded to force the plugs in with a prybar... I know how it sounds and it was trickey but worked like a charm!

I have ATF in my trans but in the cold it doesnt like to shift at all... Anybody else have this issue around like 10* F?

sthorvictor
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Re: What fluid for a M50D?

Post #9 by sthorvictor » Mon Feb 23, 2015 8:50 pm

Yup, i just call em shift rods, or detent rods. And a little bit once it gets some temps its fine, im thinking its the fluid drag on the countershaft gears when the fluid is cold. It puts the syncros to work to match shaft speeds soo takes a bit more to slip er in gear. The problem is more pronounced in a worn trans, also in non syncronized trans in general hence part of the reason for 'double clutching' :wink:
Best of luck,

Seth

turbocharged maf 300 f150

jjona5
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Re: What fluid for a M50D?

Post #10 by jjona5 » Tue Jul 26, 2016 1:13 pm

I put Mercon V in mine.

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