When I shift from Park to R or D I get some kind of groan. The ATF dipstick shows a full level and it is red so that's not a problem. I did do a drain of the fluid pan back in August and refilled with Mercon V. I'm not sure if the factory load was Mercon or Mercon V since I've heard that Ford stopped using Mercon in 1999(?). My owners manual shows Mercon for the ATF. My research says that Mercon and Mercon V can be mixed regardless. The car shifts like it normally does but it has always been rough shifting at times - especially going from Park to Reverse or Drive - sometimes there's a delay in shifting. Did I mess up with the fluid or is it that it's coincidence that the AT is making this noise?
I think you're good. My 2001 owner's manual says Mercon V for automatic transmissions. It also says the recommended type is indicated on the dip stick. My Chilton's manual says the automatic transmissions take Mercon for 1998 and earlier, Mercon V for 1999 and later. No distinction about the 4R70W. It also says Mercon and Mercon V are not interchangeable. Then they changed their mind when Motorcraft decided to discontinue Mercon. Mercon V magically became the replacement and confusion ensued.
If you read your owners manual, you may see how dedicated Ford was to the theory that Mercon and Mercon V were 100% not interchangeable. Mixing them was warned against and voids the warranty. My 1999 Ranger's manual also says it can't be mixed, but the dipstick is stamped with Mercon V only as well. Good job Ford.
They made it clear as mud, didn't they?
Pretty much, haha. I'm wondering if they did some sort of recall or added these stamped dipsticks in dealer servicing some time after the fact. It would seem really odd to me that they put that on the dipstick and then the warning in the manual at the same time. I suppose it is possible, but that would have caused a ton of confusion.
That is odd. Maybe they ran out of the old ones and decided to just use the new type.
The car is 20 years old. How many times was the fluid and filter changed per the maintenance schedule?
The first and only change was at 68,000 miles. The current mileage is just under 72,000. I've been looking through the maintenance schedule that came with the owners manual and there's no mention of a schedule for changing the fluid or filter in a 4R70W but there was a 30,000 mile (and multiples of 30,000) fluid change (but not the filter) for other automatic transmission types. The owners manual says not to mix Mercon and Mercon V but since Ford stopped making Mercon it has been said that ATF designed for both Mercon and Mercon V can be used. There is a TSB that says that Mercon V can be used with this transmission though.
TSB 01-15-7 ATF Usage Chart shows that Mercon V is suppose to be used with the 2002 model year with a 4R70W AT. So I'm safe with using Mercon V?
By golly, it does say Mercon V on the dipstick. I wonder why I never noticed that before.
I still need to figure out why it groans when going from P to R or D on occasion. We're getting hammered by snow today and I don't have a heated garage so I'll have to postpone looking into this. Good thing I have a second vehicle (and it's 4WD).
I don't know what to say about the groan. Hunt around for similar issues on Youtube while you're snowed in and see what you can learn. 💡