and88TC said:Thanks for the replies. The reason I hesitate to go to Mercon V is this part of the tech article about Merc V and its compatability with seals in the earlier transmissions like my '94:
96 and up T-Birds & Cougars with the 4R70W use Mercon V. It can be used in the '94-'95 cars, but it is not recommended by Ford. Mercon-V is a
semi-synthetic ATF, introduced in 1997 for use in vehicles equipped with the 4R44E or 5R55E transmissions. The '98 model year 4R70W transmission, AX4S and AX4N transaxles use Mercon-V.
TSB-98-8-8 states: "Mercon-V is not interchangeable with the current Mercon service fluids. Using the incorrect fluid may cause transmission or translate concerns."
When asked why? Ford responded, "The synthetics work their way past seals and cause leaks and/or durability concerns". "The 1998 transmission seals are updated to prevent these problems" - Dayton Ford Service Technician.
(quotes from this thread )timb said:To put your mind at ease I have been using MercV in my origional 94 trans since 50,000 and now 205,000 it isn't going to ruin your trans
FLUIDS LABELED MERCON®V ARE RECOMMENDED FOR SERVICING 1992 AND BEYOND AODE/4R70W TRANSMISSIONS WHICH ORIGINALLY SPECIFIED MERCON®.
TSB 01-15-7's chart says that only starting in 1998, 4R70W transmissions should use Mercon V.
It also states that TSB 01-15-7 supersedes TSB 98-8-8 (which had that unreadable chart).
I also found
(quotes from this thread )
Sigh. Can I use Mercon V or not? Did the 4R70W transmission change in design in '98?
By the way, I did use search, but since all the threads and TSBs give contradicting info, I decided to post (again) instead.
-------------------------------------Rolling-Thunder said:I have been using Mercon V in my T-Bird, for about 50,000 miles, too.
I switched over at the 140,000 mile mark (while doing J-Mod), and have not had any problems- PERIOD.
The tranny has 193,000 miles, and has never been rebuilt.