T5O-D Fluid change, use Mercon Auto Fluid? or 80W gear oil?

Henceforward

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Jul 17, 2001
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I want to change the fluid in my T5 manual 5 speed.

T5 Overdrive Fluid change, use Mercon Auto Fluid? or 80W gear oil? The book says use Mercon for the T50-D.

What gear oil do I use, and how much does it tak to fill it up? I could not find a capacity in the Haynes manual.
 
Oh... if it's in the car, you'll need a cap with a short hose to 'squirt' it into the fill plug. Some tranny fluid containers come with this while many don't. I use the top off of a gear oil container and a short length of clear hose.
 
i have a fluid pump/suction gun

it worked pretty good, kinda messy. I used to be a technician so i had one from that. something else i bought a basin pan (designed to go under clothes washer) from lowes. it's about 3 ft square. it's good for catching small spills and runover when doing stuff like that.
I used redline d4 it's a syn replacement for mercon III, which is what was recommended by the intructions in the King Cobra clutch kit I just installed.
 
1EVIL88VERT said:
I fill mine through the shifter....much less of a p.i.t.a just take out the fill port{the plug on the top} and it will over flow when its full. Stick it in and you done. :nice:

Unfortunatly when I installed my MGW I didn't change the gear oil :bang: , so I am not going to tear it back off. I think I might try my luck with a hose, and top it off with a baster that I have.

Thanks for the help, 3 quarts tomorrow. I can't even get to the store because my battery died.
 
Daggar said:
Use Mercon. The seals in the T-5 are designed for Mercon.
so were the needle bearings. :)


D4 is good stuff - i thought about changing to something else last time, but Adam convinced me not to. :)
 
HISSIN50 said:
D4 is good stuff - i thought about changing to something else last time, but Adam convinced me not to. :)

Don't blame me! :D

I think any synthetic is good stuff, I wouldn't hesitate to run Redline D4, M1, Amsoil, etc. I might try Synchromesh when I do this AOD-T5 swap -- I've never run it in a T5 before but have heard good things.

The one thing I would not run again is Redline MTL. It did not work well with the temperature changes at all (which I don't recall being that much), and I did break that transmission pretty quick -- but don't know if that was why.
 
89MustangGX said:
Don't blame me! :D

I think any synthetic is good stuff, I wouldn't hesitate to run Redline D4, M1, Amsoil, etc. I might try Synchromesh when I do this AOD-T5 swap -- I've never run it in a T5 before but have heard good things.

The one thing I would not run again is Redline MTL. It did not work well with the temperature changes at all (which I don't recall being that much), and I did break that transmission pretty quick -- but don't know if that was why.

i agree about all the big name synthetics being good. :nice:

i had called their (Redline's) tech line when i made the switch initially (before i had internet) and specifically asked if i could run MTL since it is so hot where i live (desert SW). they were pretty against it. ive run it in other cars though (or mixed it and MT90 for applications callling for gear oil in the trans). but for a trans calling for ATF, i doubt i would go thicker - dont want starvation.
 
HISSIN50 said:
i had called their (Redline's) tech line when i made the switch initially (before i had internet) and specifically asked if i could run MTL since it is so hot where i live (desert SW). they were pretty against it. ive run it in other cars though (or mixed it and MT90 for applications callling for gear oil in the trans). but for a trans calling for ATF, i doubt i would go thicker - dont want starvation.

This was many years ago...I had talked to Bob Hanlon about a T5 that I just had built and he said I could go with either MTL or D4, but he preferred the MTL. He said to watch the temperatures though and if I was going to run year round to run the D4. They were both new to me, so I went for the 'better' MTL. Didn't even make it past that summer. :(

After that I went right to my first Tremec and Synchromesh. :nice:
 
This will work correct?

dexronIIImercon_mexico_106x261.jpg
 
Alright, I got it done, not really that hard under the car. I took a clear tube, stuck a small funnel at the top end of it, ran it down the firewall and inserted it into the transmission. Basically I used a "beer bong" to get the fluid in there. I ran a bead of RTV around the drain and fill plugs to make sure they don't leak. I did not use the baster.

The old stuff was the original gear oil. The plugs still had the yellow assembly paint on them. The old fluid was dark maroon-orangish, not pink-red like the new stuff.

Is it ok if I change the T5 fluid every year? :shrug:
 
Stang8URMPRT said:
Ford Recommends changing the fluid in a T-5 every 10,000 miles. :D
another dealership gem from Nick. :) my owners manual says the trans fluid does not have a service interval and is good indefinately. 10K is a tiny! service interval for any trans, let alone a stick which does not stress its fluid at all!
not doubting you at all Nick - you are privy to info that many of us (me included) are not.

real-world speaking, i would have no qualms about letting the fluid go for a bit longer than that, and synthetic indefinately if not beaten upon.