Mercon LV vs Mercon V

Ford transmissions split into generations by fluid spec. Mercon V is the older 4R70W/AOD-era fluid. Mercon LV is the modern 6R80/6F35 spec. Mercon ULV is the latest (10R80/10R140). They are NOT interchangeable. Mixing them is the #1 cause of TCC shudder complaints.

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Mercon V

Use in 4R70W, 4R75W, AOD, AODE, 5R55E. Older 4-speed Ford RWD.

When to use: Stock spec for 1995-2008 Ford automatics.

Wrong-fluid consequence: Putting Mercon V in a 6R80 = immediate TCC shudder + slip. Drain twice with Mercon LV to recover.

Mercon LV

Use in 6R80, 6F35, 6F50, 5R110W (some variants). Modern Ford 6-speed.

When to use: Required for 2009-2017 F-150, Mustang, Edge, Fusion, Escape.

Wrong-fluid consequence: Wrong-fluid use causes 6R80 TCC shudder within 5K miles. Mercon LV is mandatory.

Mercon ULV

Use in 10R80, 10R140, 8F35, 8F57. The newest Ford spec.

When to use: Required for 2017+ F-150, Mustang, Expedition, Super Duty.

Wrong-fluid consequence: Backwards-compatible with Mercon LV in some applications but check the manual. Using Mercon LV in a 10R80 may work short-term but voids warranty.

NEVER mix Mercon V and Mercon LV - they have different friction modifiers. Drain + refill with the correct spec or the rebuild will shudder within 5K miles.
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