Seems to be. You and Tex have the 08 and 09 requiring that stuff. The rest of us are supposed to use ATF in our ZF-6

 

there is a tsb to use merc v in the zf, not sure on all the year ranges. but it included my 08 to improve cold weather shifting.

 

I'll stick with what it was designed for...

I can shift just fine in the cold.

 

I'm not saying you're wrong. I'm just wondering what changed in the ZF-6 between yours and mine. Was there some internal modification, or did they find out atf didn't work as well? I've got over 320k on my ZF-6 running ATF with no issues.

 

actually, I have no clue...

 

Sold...staying with standard Merc V in my 2000 ZF when I change out fluids this spring. No issues at 320K miles speaks volumes.

 

I am not 100% sure on the superdutys, but a while back there was a service bulletin at ford to replace ATF fluid in the manual trans with motorcraft 75w-90 full synthetic manual trans fluid at whopping $25.00 a quart. I know for a fact this applied to the focus and mustang among others. each model had its own bulletin that said the same thing.

Also for years I have been running 10w-30 in my chrysler 5-speed which originally called for ATF with a huge increase in performance and feel.

If i were to guess they probably chose atf over gear oil as it was a thinner fluid less likely to cake up from heat and yet stay thin in the extreme cold. Other than that there is no hydraulic system in a manual trans , just gears spinning, so I highly doubt it matters so much as to what u use.

My only concern would be chemical compounds and their reaction to internal components. IE... you do not want to add a fluid type that is corrosive to brass etc. last I heard regular 10w30 didn't eat anything but certain synthetics may. I would stick with fords brand

 

The ZF6 has a pump and cooler.

 

Since this is back from the dead, I'll go ahead and update.

Now sitting at 440,000 miles on the original ZF-6 swapping the ATF every 50k miles. I have had to replace the clutch twice now though. They only seem to last me a couple of hundred thousand miles.

 

I throw in an update...

116,000 miles on the original 75w-90 "MTF" without issue. I'm considering changing it out on this long weekend.

 

I would have to look again, but I was sure that the manual called for ATF. So when I swapped the fluid out last year I used Amsoil synthetic ATF like the picture below.

 

I recently switched to "Valvoline Maxlife Dex/Merc ATF " . It is fully synthetic and its compatibility statement says:


Recommended for use where DEXRON, DEXRON II, III and VI, Toyota T-IV and WS, MERCON®, MERCON® SP and LV, Allison TES 389, Nissan Matic-D, Matic-J and Matic-K, Honda Z-1 (except CVT), Mercedes NAG-1, Mitsubishi Diamond SP-II and SP-III and many others are required.


I got mine at Walmart (6 qts. for ZF6 ) .

 

Guess I can update to. 510,000 miles now and I've started substituting in 1 qt of MTF for the fluid and just mixing it with the ATF. Seems to help some of the shifts when going over bumps so it doesn't grind as much.

Still change the fluid every 50k, still comes out looking clean, still running the factory transmission with no rebuilt parts.