6R80 Shift Kit 2015

Ford redesigned the 6R80 valve body for vehicles built after December 2014, and the GEN1 repair kits that worked on earlier trucks do not fit it. This is the kit for the later unit: the new TransGo SK 6R80-G2, built for the GEN2 6R80 from 2015 on, with or without start-stop, and for the 2017-up 6R100. If your 2015-2017 F-150, Expedition, Navigator or Mustang quivers at light throttle in the 30s and 40s, slips and slides into gear once it is hot, or clunks as you coast to a stop, the pressure regulator and converter clutch regulator circuits are where TransGo found the wear.

What the shift kit does in a GEN2 6R80

The GEN2 valve body uses a larger pressure regulator valve than GEN1, but the failure is the same: the valve and its boost bushing wear their bore, line pressure turns erratic, and every clutch takes longer to apply. The converter clutch regulator valve also needs a recalibration to stop the light-throttle quiver. The G2 kit carries a patented two-piece hardened steel PR valve sized for the GEN2 bore, a new aluminum boost bushing, a steel TCC regulator valve, two calibration springs, four bore plug wire retainers and six new solenoid damper inserts. The longer valve lands ride on unworn sections of the bore, so the repair is drop-in with no reaming. It brings back crisp, consistent shifts; it is a repair kit and not a harsh-shift performance calibration.

Symptoms on 2015-up trucks and Mustangs

• A tire-like vibration around 28 to 46 mph while the converter clutch is locked
• Erratic line pressure: soft shifts one moment, firm the next
• Coast-down clunk, especially hot
• Gear ratio codes P0729 and P0731 to P0734; shift performance codes P0781 to P0784 and P0829

A 2015-2017 F-150 that suddenly drops several gears at speed, lights the wrench lamp, or shows a false gear position is a different problem. Ford's 2026 recall 26V-237 traces that to lead frame degradation sending a false range sensor signal, and the fix is a lead frame and software, not this kit. Our F-150 6R80 shift problems guide sorts out which complaint you have.

How to confirm before you buy

Check for open recall work on the VIN first. Then check the fluid hot on a scan tool, because low level copies every symptom above. Read stored codes: ratio and performance codes without electrical circuit faults point at worn valves, while circuit codes point at solenoids or the lead frame. Also ask whether the computer was recently reprogrammed. Ford's TSB 20-2060 notes that shifts can feel firm for several days of adaptive relearn after a reflash, which is normal and not a reason to buy parts. Our 6R80 harsh shift guide covers the relearn side in detail.

Fitment

This kit fits GEN2 6R80 valve bodies, which Ford's parts catalog shows on all vehicles built after 12/2014, plus the 6R100 from 2017. That covers 2015-on F-150, Expedition, Navigator and Mustang with the six-speed, start-stop or not. The catch is the changeover period: some 2014 and early 2015 vehicles, and some replacement GEN1 valve bodies, look like GEN2 because they have the extra filter hole. Measure the original PR valve land before installing. A .514 in reading is GEN2 and this kit fits. A .495 in reading is GEN1 and needs the 6R80 GEN1 shift kit instead. Send us your year and VIN if you want us to check. Browse the rest of the family on our 6R80 parts page.

Install notes

• Mark every solenoid location before removing it. The brown-snout variable force solenoids (TCC, SSA, SSC) and black-snout ones (SSD, EPC, SSB) carry a calibration number from 2 to 5, and any replacement must match the number that came out of that bore.
• Install the large white PR spring inside the new boost valve, then the new PR valve and four-groove cap, and reuse the original retainer.
• GEN2 separator plates use bonded gaskets and six dampers. Start-stop models add an 8 mm steel ball and spring, so put every small part back where it came from.
• Use Mercon LV and set the level hot. Valve bodies past about 140,000 miles usually also need fresh solenoids, such as a 6R80 solenoid kit, or a replacement 2015-2017 6R80 valve body when the bores are too far gone.

How do I know if my 6R80 is GEN1 or GEN2?

Ford's parts catalog shows GEN2 on vehicles built after December 2014, but the only sure check is the PR valve. Remove it and measure the land: .514 in is GEN2 and takes this kit, .495 in is GEN1 and needs the GEN1 kit.

Does it fit a truck with start-stop?

Yes. TransGo lists the G2 kit for GEN2 valve bodies with or without start-stop. Start-stop units have an extra steel ball and spring in the valve body that must go back in its original location.

Will this fix the sudden downshift recall on my 2016 F-150?

No. Ford's recall 26V-237 for 2015-2017 F-150s is a lead frame problem that sends a false gear position signal. Have the recall checked by VIN first; this kit repairs worn pressure and TCC valves.

Does it fit the 6R100 in a Super Duty?

TransGo lists the SK 6R80-G2 for the 2017-and-later 6R100 as well as the GEN2 6R80.

What fluid goes back in?

Use Mercon LV and set the level with the fluid at operating temperature, read on a scan tool. Expect some adaptive relearn after the install.

• 6R80 F150 Shift Problems: Diagnosis and Fix
• 6R80 Harsh Shift Causes and Fix
• 6R80 Mustang Shift Problems: Diagnosis and Fix
• 6R80 Shift Solenoid Symptoms and Replacement