6 speed fluid
Elder User
Joined: Dec 2001
Posts: 527
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From: Central WA USA
ZF on their website pretty much approves a giant list of approved fluids, but Ford specifies mercon. So I just use Mobil 1 ATF. It made such a huge difference in shifting and noise seemed to be less as well. I changed the Mobil 1 out at 60k and the fluid was still very new looking compared to when I drained the factory fill. I will not be changing the fluid out anymore based on that last drain unless something feels or sounds wrong.
FTE Leadership Emeritus
Joined: May 2001
Posts: 13,653
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From: Cabot, Arkansas
The synthetic fluid does make a big difference. I currently have Amsoil in mine, but will most likely switch to Royal Purple when it's next due (~5,000 miles) because it's more readily available.
If you get the tranny cooler fully drained the system will hold just a hair over 6 quarts. Plus 2 more quarts for the transfer case if your trucks a 4x4.
If you get the tranny cooler fully drained the system will hold just a hair over 6 quarts. Plus 2 more quarts for the transfer case if your trucks a 4x4.
Senior User
Joined: Apr 2004
Posts: 349
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From: Port Murray, NJ
Yes, they have coolers if you have 2 hard lines going from your trans to your rad. Very easy to tell when under the truck.
Question for you guys using the synthetic. Did you find it shifted better after draining out the regular atf and adding the synthetic? I bought my truck used and someone filled my ZF with gear oil so it was a bear shifting in the winter. I changed it out asap and put in standard atf. I'm thinking of changing it again to synthetic atf and was wondering if it is worth the extra $$$.
Thanks
Question for you guys using the synthetic. Did you find it shifted better after draining out the regular atf and adding the synthetic? I bought my truck used and someone filled my ZF with gear oil so it was a bear shifting in the winter. I changed it out asap and put in standard atf. I'm thinking of changing it again to synthetic atf and was wondering if it is worth the extra $$$.
Thanks
Last edited by wilbur996; May 17, 2006 at 12:56 PM. Reason: additional info.
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FTE Leadership Emeritus
Joined: May 2001
Posts: 13,653
Likes: 6
From: Cabot, Arkansas
Did you find it shifted better after draining out the regular atf and adding the synthetic?
I'm thinking of changing it again to synthetic atf and was wondering if it is worth the extra $$$.
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Elder User
Joined: Dec 2001
Posts: 527
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From: Central WA USA
It was worth it for me, since it shifts so much smoother into 2nd and 3rd in the winter. Plus, I don't think I'll change it again since it was so clean the last time I drained it out, or at least I'll double the drain interval.
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Joined: May 2001
Posts: 13,653
Likes: 6
From: Cabot, Arkansas
Left side of the tranny, about 1/4 of the way up. Same type of plug as the drain hole underneath.
If you need to you can remove the shifter and pour it in from the top.
If you need to you can remove the shifter and pour it in from the top.
Last edited by cookie88; Sep 17, 2006 at 08:45 PM.