6F50 Shift Kit 2007

This is a new TransGo SHIFT KIT valve body repair kit for the Ford 6F50, the six-speed transaxle that debuted in the 2007 Ford Edge and Lincoln MKX. TransGo builds this kit to fit every 6F50 and the heavier-duty 6F55 from 2007 on, so it is a strong match for an early 2007 unit. Owners usually land here with erratic or harsh shifts, a converter clutch that hunts on the highway, or a string of gear ratio and solenoid codes that a new solenoid body did not cure.

What the shift kit does in a 6F50

Like its smaller 6F35 cousin, the 6F50 relies on solenoids to apply every clutch, and those solenoids depend on a stable feed pressure. The solenoid pressure regulator valve holds that feed at a set value regardless of line pressure. Wear in its bore lets the value drift, so the solenoids over- or under-apply clutches and the TCM logs ratio errors. TransGo's kit installs a drop-in steel bushing and hardened regulator valve that restore control in the original worn bore. It also supplies a new main pressure regulator valve with longer lands, a TCC control valve spring, and a new pressure relief system that replaces the factory isolator valve line-up to protect hard parts from pressure spikes.

Symptoms this kit addresses

• Erratic upshifts and downshifts, harsh one day and soft the next
• Torque converter clutch that hunts, slips or cycles on and off at cruise
• High or low line pressure from a worn pressure regulator bore
• Ratio codes P0729 and P0731 through P0735, TCC code P0741
• Solenoid performance codes including P0751, P0756, P0761, P0766, P0771 and P07A5
• Broken internal parts after an over-pressure event

How to confirm it is a valve body problem

Read stored codes and note whether they point to one clutch or several. Check the fluid: if it is dark and full of friction material, the clutches need attention first, and the 3-5-R pack is a common casualty in this transmission family. A clean-fluid unit with multiple solenoid performance codes, or codes that return after a solenoid body swap, points toward regulator bore wear. Our 6F35 and 6F50 failure guide explains how to separate the two.

Fitment

This kit is listed for the 2007 6F50. TransGo rates the same kit for all 6F50 and 6F55 units from 2007 on in Ford, Lincoln and Mercury vehicles. It is not a 6F35 kit; those transmissions use their own Gen 1 and Gen 2 kits. Confirm your transmission model on the ID tag or send us your year and VIN. More parts for this family are on our 6F35/6F50 parts page, and a later listing is the 2007-2018 6F50 shift kit.

Install notes

• Pull and disassemble the valve body on a clean bench and follow the TransGo instructions in sequence.
• The relief system goes in place of the OE isolator valves; do not reinstall the old parts alongside it.
• If a solenoid has failed electrically, replace it now; the 2007 6F50 solenoid body fits Edge and MKX.
• If you rebuild at the same time, check the front pump; a 6F50 oil pump assembly is available for 2007-2012 units.
• Refill with Mercon LV, verify level at operating temperature, reset adaptive shift data and road test through all gears.

Does this kit fit the 6F55 too?

Yes. TransGo rates this kit for all 6F50 and 6F55 transmissions from 2007 on. It does not fit the 6F35.

Is reaming required?

No. The solenoid pressure regulator bushing, the main pressure regulator valve and the relief bushing are drop-in parts designed to work in the original bores.

Will it fix my converter clutch hunting at highway speed?

Erratic or hunting TCC is one of the complaints the kit is designed to correct when it is caused by valve body wear. A worn torque converter clutch lining needs a converter repair.

Does it come with a separator plate?

TransGo's contents list for the 6F50 kit covers valves, bushings, springs, retainers and the relief system. It does not list a separator plate, so reuse a plate in good condition or source one separately.

What fluid does the 6F50 take?

Mercon LV. Do not mix in other fluids after the valve body work.

• Ford 6F35 Transmission Problems: Real Causes and the Fixes That Last