Last updated October 15, 2026

2020 Ford F-250 (Regular Cab)

2020 F-250 regular cab 10R140 shifts hard or late

Symptoms

Ford technical service bulletin 21-2420, dated November 24, 2021, says some 2020 F-Super Duty trucks with the 10R140 automatic transmission may engage harshly, shift harshly, or shift late. The truck may also show a wrench light and one or more of the diagnostic codes the bulletin lists, including P0729, P0731 through P0736, P076F, P07D9, P07F7, and P2700 through P2705. NHTSA complaint ODI 11752304, filed on a 2020 Ford F-250 regular cab, describes a 10R140 paired with the 6.7-liter Power Stroke, a build date of November 2019 at the Kentucky plant, and 84,000 miles. The owner wrote that engagement into drive and reverse is harsh, that shifts flare as if the transmission goes to neutral between gears, and that the truck has shifted from 4th to 1st.

Likely causes

Bulletin 21-2420 says the harsh or late shift may be sticking valves in the main control valve body. It does not apply to every 2020 Super Duty. A 6.7-liter truck built on or before February 10, 2021, that has only code P07F6 is sent to a different article. A 6.2-liter or 7.3-liter truck built on or before April 1, 2020, that has only code P07F7 is also sent elsewhere. The regular-cab complaint names a 6.7-liter engine and does not list a code. The owner also wrote that Ford bulletins cover a CDF bushing. That is the owner's statement. Bulletin 21-2420 does not name a CDF bushing. It names the valve body.

Common fixes

Bulletin 21-2420 tells the dealer to run the transmission accelerated main control break-in routine three times for the clutch the workshop manual points to, with the truck on a frame-engaging lift and the wheels off the ground, then an adaptive-learning drive. If the harsh or late shift is still there, the bulletin says to overhaul the main control valve body. The adaptive drive can make shifts feel firmer than normal for several days. These are dealer operations. The complaint does not describe a finished repair. If the truck bangs into gear or flares between gears, take it to a Ford dealer and ask whether bulletin 21-2420 applies to that VIN.

DIY difficulty

Not a DIY job in these sources. Ford's bulletin says the procedure is for a trained technician with the tools to do the job, and it says not to assume the condition is on your truck.

Parts needed

The bulletin lists causal part 7A100 for the claim. Parts it may use include separator plate kit LC3Z-7A008-E or LC3Z-7A008-F, solenoid retainers, and Mercon ULV fluid. The pan gasket, filter, and seals are listed only if the dealer finds they are needed.

Warranty notes

This is not a recall. Bulletin 21-2420 says coverage follows the new-vehicle limited warranty, a service-part warranty, or an extended service plan when the causal part qualifies, and that a dealer has to confirm the bulletin applies. The regular-cab owner wrote that the truck was outside the 5-year warranty at 84,000 miles. That is one owner's account. It is not a coverage decision for another 2020 F-250. The 2022 F-250 crew cab tow/haul downshift is a different bulletin and a different page.

Sources

• Ford TSB 21-2420 on harsh or delayed 2020 F-Super Duty 10R140 shifts
• NHTSA complaints for 2020 Ford F-250 regular cab (ODI 11752304)