Ford specifies Mercon V. On a Ranger forum I'm on several members there insist I should stick with Motorcraft Mercon V, period, to preserve the trans. They say don't change to Amsoil or even other brands of Mercon V, just Motorcraft.
The truck is rear-drive (not 4WD) and had 101,000 miles after I bought it in April. The day after delivery, I had the ATF flushed and fluid and filter changed at a local shop with the BG machine. I'm sure BG's universal fluid was used. The change was a priority, "any port in a storm", because I am sure no ATF change had been done on this truck before I bought it. Ford was saying "lifetime fill". As you'd expect, members of the Ranger forum were not happy about the BG ATF being used in the trans either.
Originally I had planned to drop the trans pan eventually, install a drain plug, top off with Amsoil, then change what was in the pan every 15,000–20,000 miles with more Amsoil. But the 5R55E has some well known weaknesses, and I want what's best for longevity. The trans shifts fine, by the way.
What do you think of this advice to stick with factory fill for this transmission? I still lean toward going with Amsoil, but your thoughts about sticking with Motorcraft Mercon V, please.
The truck is rear-drive (not 4WD) and had 101,000 miles after I bought it in April. The day after delivery, I had the ATF flushed and fluid and filter changed at a local shop with the BG machine. I'm sure BG's universal fluid was used. The change was a priority, "any port in a storm", because I am sure no ATF change had been done on this truck before I bought it. Ford was saying "lifetime fill". As you'd expect, members of the Ranger forum were not happy about the BG ATF being used in the trans either.
Originally I had planned to drop the trans pan eventually, install a drain plug, top off with Amsoil, then change what was in the pan every 15,000–20,000 miles with more Amsoil. But the 5R55E has some well known weaknesses, and I want what's best for longevity. The trans shifts fine, by the way.
What do you think of this advice to stick with factory fill for this transmission? I still lean toward going with Amsoil, but your thoughts about sticking with Motorcraft Mercon V, please.