OK... according to information I've gathered from around the web, and from the bottles of ATF I've used (and have had used), Mercon V is now the recommended replacement fluid for my 1996 Ranger Supercab 3.0L 2WD 4r55e (I think) tranny, and Mercon V is in there now (flush and fill, so it IS mixed with Mercon to some small degree).

Mercon was specified in the truck's owners manual, which has warnings against mixing ATF types. Apparently Ford has issued one or more TSB's indicating that Mercon V is good to add or replace that override these warnings for vehicles that came with Mercon.

So... my questions:
1) Is Mercon V good in a trans that originally specified Mercon?
2) Will the current mix of Mercon V with what remained of the Mercon cause (new) problems down the road?
3) Can the trans be topped off with regular Mercon without doing any damage? (I have several quarts of this left).

Thanks in advance!
Lee

 

I used Mercon V when I changed the fulid with no issues. I would try not to mix the two types of fluid. I know some probably mixed when you drained the tranny and filled it back up using Mercon V but in the future I wouldnt mix and match... just my two cents.

 

Actually I didn't do the mixing... the 'tech' did even after seeing the owners manual that specified Mercon. That's fine, though, since Mercon V is supposed to work, and the spilled ATF is now all over HIS shop floor rather than my driveway :)

 

Mercon and Mercon V can be mixes in transmissions, but not in transfer cases.

Unless you disassemble your transmission and dry it out, you will have some residual Mercon.

Mercon V isnt supposed to be used in transfer cases with electronic clutch coils

 

Its 2wd, so transfer case mixing is a non-issue for me.

I'll probably be dropping the pan again in a while to replace the shift solenoids (if the flush /filter/refill doesn't clear up an intermittent code that being tossed), so it's good to know I have fluid that I can use that won't cause a problem.

Thanks!

 

You shouldn't have a problem since Mercon V is semi-synthetic. I do believe Mercon VI is full synthetic but to use that I would recommend a complete system flush.

 

Mercon is not synthetic and Mercon V is semi-synthetic. I dont think there is such a thing as Mercon VI. Ive heard of Dextron VI but not Mercon.

 

Thanks to everyone for their help! I got the info I needed, and really appreciate everyone's input!

Since this thread appears to be moving towards yet another "which ATF is better?" one, please close it.

Thanks again for all your help!

 

Since you have a 96, I would go with Just regular Mercon, its what It came from the factory with. When I changed from Mercon to Mercon V in my '97 the shifting got alot rougher. i had to switch back.

 

Lot of info out there but I think some are confused. Here is my opinion:

Previously, on earlier Fords, if your tranny said to use Mercon, Ford said you should NOT mix it with a fluid marked only Mercon V. The confusion arises because of this:

There is Mercon fluid
There is Mercon V fluid and now Mercon VI
There are now newer fluids that say Mercon V or VI / Mercon compatible.

When Ford said NOT to mix Mercon V with Mercon, it meant that if you have Mercon in the tranny, that you should not use a fluid marked Mercon V alone.

BUT...I believe that it is OK to use a newer fluid marked Mercon V/Mercon compatible because those newer formulations are backward compatible with straight Mercon whereas a fluid marked only Mercon V is NOT compatible with Mercon.

Anyone else find the same????

 

the people you are talking to at ford must not be too smart. TSB 06-14-4 says Mercon V replaces all Mercon applications.