I just purchased a used transmission for my 05 s-type. It has the v8 with the zf6hp26 six speed automatic. We are installing the used transmission today (only 73K miles). What type of fluid should I go back with? Also, the transmission cooler lines are leaking so that needs to be fixed. Has anyone fixed the cooler lines that can give some pointers?


Is there any crossover fluids for the transmission?


Thanks, Kelby

 

I called auto zone. The guy said it used Castrol Import Multivehicle ATF. Should I use this fluid?

 

ZF Lifeguard 6 is used by factory on these transmissions I believe. When I changed my ZF6HP26's transmission pan filter/fluid I used ZF Lifeguard 6, runs great, not cheap as the other stuff but if you're picky like me you'll pay for it lol.

I've seen posts where other folks used other brand ATF like motorcraft in their ZF6HP26's and worked just fine...there's LOTS of posts on this topic just search the forum for something like 'ZF6HP26 fluid' or something like that. If you do buy the ZF Lifeguard 6 I recommend buying 7 liters not 6. Good luck !


6 Liters ZF Lifeguard 6 Automatic Transmission Fluid S671090255 | eBay

 

A cheaper option is Ford Motorcraft Mercon SP fluid.

Like campaign308 - I opt for Lifeguard 6 oem spec fluid.

 

I have a complete spare ZF service kit for the transmission which I ordered before I realized my car's tranny had been serviced already by the previous owner so if you are looking for the correct fluid, pan/filter and replacement sleeve seal along with a few spare bolts you can PM me and we can work it out. The kit comes with 6 liters of the correct ZF fluid which lists for about $30 per liter. The kit cost me nearly $300 including but am willing to take a (small) hit on it if someone can put it to good use.

 

When I decided to do a drain-and-fill on my 2005 S-Type 3.0 a couple of months ago, I selected Mercon SP ATF. I had researched suitable ATFs for years and opted for Mercon SP because it meets the necessary Shell M1375.4 specs, Ford runs it in the ZF 6HP26 transmissions installed in the 2006 to 2009 Lincoln Navigator, and I believe it to be exactly the same formulation as Lifeguard 6 except for the color (Lifeguard 6 is gold while Mercon SP is red). Since we did the drain-and-fill on November 5th, my S-Type shifts more smoothly (especially in the lower gear range) and has not missed a beat. Any future drain-and-fills on either of our ZF 6HP26 transmissions will be with Mercon SP. It simply makes perfect economic sense to me after doing the necessary research....

 

I personally used Lifeguard 6 when I did my transmission fluid change, but now that I see more information on Mercon SP, I would go with that fluid next time around.

If you want Lifeguard 6, Amazon is selling it for like $20-ish dollars a bottle.

 

The transition part supplier look up the fluid for it. He said to use synthetic dexron 6 while adding one ounce of lube guard platinum per quart of fluid. The fluid in the transmission is a gold color, but the dexron 6 is red. Is it okay to mix these together? I just bought the dexron and lube guard today.

 

I would caution using Mercon Dexron 6 period. (Dexron is usually for domestic transmissions - the 6HP26 is a foreign transmission (German I believe)

I know Ford Motorcraft Mercon SP is suitable replacement for Lifeguard 6

 

@abonano, I would be mixing the lube guard with platinum with the fluid. Should I still caution using this fluid?

 

I would for sure - let's see what others have to say (I'm no ZF Expert)

But I only heard of 3 types of fluid being used:

Lifeguard 6 (OEM Spec)
Ford Motorcraft Mercon SP
Castrol Multi Import

 

I suppose cutting corners to save a few $$$ is OK if it works but if it doesn't then a replacement gearbox is a lot of $$$.

I wouldn't do it.

 

@JagV8, would it be wise if I take the dexron 6 back and get the ford motorcraft mercon Sp? And is it okay to mix the new fluid with the old fluid that is left in the transmission? The old fluid looks good and does not smell burnt.

 

Mixing Mercon SP ATF with the original Lifeguard 6 ATF is fine. That is exactly what I did since a routine drain-and-fill typically gets only 5 to 6 litres of old ATF out of the ZF 6HP26 (it holds 10 litres total). Do not use Dexron ATF. It does not meet the required Shell M1375.4 specs....

 

Just as it's important to use the correct fluid, the drain and refill procedure must be followed to the letter also.

I'd stop listening to the guy behind the parts counter. Their free advice can sometimes turn out to be quite costly.

 

@mikey, do you have a link for a correct procedure for the drain and refill? Also, do I have to purchase the Mercon SP from Ford?

 

If you've decided on the Mercon fluid, buy it wherever you like. Maybe Amazon.

The flush procedure can be found in the stickies at the top of the page.

 

Thanks for the advice, I will be taking the dexron back now and purchasing the Mercon SP.

 

Big +1 on following the refill procedure to the letter, especially monitoring transmission fluid temperature during refill. You must ensure a stream of fluid or trickle coming out of the fill plug at 40 degrees C. Also, the trans pan must be level.... anything less or cutting corners is asking for trouble!!!

Read up a few times before attempting this. If your just exchanging fluid not too bad. if your going for the "trifecta" (pan/filter/fluid) really read up and change the sealing sleeve too...

 

If you want the best prices on the proper ZF fluid and parts use this guy;

The CTSC - ZF Parts

He gets about $19 per liter and I have not found anywhere cheaper.

I would never install a used tranny without doing a filter and fluid change. He has the entire kit for about $250.
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