2013 Lincoln MKZ 3.7L 6F50 Transmission: Problems, Identification, and Used Replacement
Identify the exact 6F50 variant for your 3.7L FWD MKZ, understand common failures, and learn when to replace it with a used OEM unit.
- Programming the replacement transmission's unique solenoid body ID and strategy into the vehicle's computer is mandatory using a Ford-specific scan tool to prevent immediate shift problems and damage.
- The transmission cooler and lines must be thoroughly flushed of all debris from the old unit before installing the replacement; failure to do so will cause immediate contamination and failure not covered by warranty.
- Only use Motorcraft MERCON LV automatic transmission fluid. Using any other fluid type can cause severe damage to internal components.
- Before mating the transmission to the engine, ensure the torque converter is fully seated by feeling for three distinct 'clicks' to avoid cracking the front pump.
- You must verify the exact fitment for a 2013 MKZ 3.7L FWD model using the VIN (8th digit 'K'), door jamb code ('TR' code 'J'), and part number, as it is not interchangeable with AWD or other engine models.
Vehicle and Transmission Identification
This article covers the 6F50 / 6F55 6-speed automatic transmission assembly specifically for the 2013 Lincoln MKZ equipped with the 3.7L V6 engine and Front-Wheel Drive (FWD). This transmission is a transverse-mounted unit, meaning the engine and transmission are situated sideways in the engine bay.
Before purchasing a replacement, it's critical to verify that your vehicle requires this exact unit. Mismatched transmissions can lead to installation failure, electronic incompatibility, and a voided warranty. Use these steps to confirm fitment:
- Check the VIN: The 8th digit of your Vehicle Identification Number (VIN) must be 'K', which designates the 3.7L Duratec V6 engine.
- Inspect the Drivetrain: Confirm your vehicle is Front-Wheel Drive (FWD). An easy check is the absence of a rear driveshaft and rear differential. This transmission will not fit All-Wheel Drive (AWD) models.
- Read the Door Jamb Sticker: On the driver's side door jamb, find the Safety Compliance Label. Look for the 'TR' column; the code for this transmission is 'J'.
- Match the Part Number: If possible, locate the white barcode sticker on top of the original transmission case. The part number should match one of these identifying codes: DA8P-PA, DA8P-PB, DA8P-7000-PA, DA8P-7000-PB, or DA8Z-7000-P.
What It Does NOT Fit
This FWD transmission is not interchangeable with other Lincoln MKZ models. Do not attempt to install it in a vehicle with:
- All-Wheel Drive (AWD): AWD models require a different transmission case that has a mounting flange for the Power Transfer Unit (PTU), which sends power to the rear wheels.
- 2.0L EcoBoost, 2.0L Hybrid, or 3.5L Engines: These engines use different transmissions with unique bellhousing bolt patterns, case dimensions, and internal gear ratios.
Common Failure Symptoms
A failing 6F50 transmission can exhibit a range of symptoms. While some issues can be resolved with software updates or minor parts, others indicate the need for a complete assembly replacement. Common signs of trouble include:
- Harsh, delayed, or erratic shifting, sometimes feeling like being rear-ended.
- Transmission slipping, where the engine RPMs flare up without a corresponding increase in speed.
- A sudden loss of specific gears, particularly Reverse, 3rd, and 5th.
- Illumination of the wrench light or Check Engine Light on the dashboard.
- Sluggish acceleration from a stop, followed by a harsh bump or engagement.
- Unexpectedly shifting into Park at very low speeds (under 5 mph).
- Intermittent neutral-out conditions, starting in 5th gear, backup camera staying on in Drive, or cruise control dropping out.
Diagnostic Flowchart
Known Issues, Bulletins, and Recalls
Ford and Lincoln have released several Technical Service Bulletins (TSBs) and Special Service Messages (SSMs) related to the 6F50/6F55 transmission family. These documents provide professional technicians with procedures to fix known problems.
Issue: Unexpected Shift to Park Below 5 MPH
- Symptoms: The vehicle shifts into Park on its own when moving at speeds below 5 mph, and the wrench light may come on with Diagnostic Trouble Code (DTC) P081F.
- Affected Vehicles: 2013 Lincoln MKZ.
- Cause: Software calibration issue in the control modules.
- Remedy: Per TSB 13-9-10, a technician must reprogram the Powertrain Control Module (PCM) and Gear Shift Module (GSM) to the latest software version.
Issue: Sluggish Acceleration from a Rolling Stop
- Symptoms: When accelerating from a near-stop (0-5 mph), the vehicle feels sluggish and then exhibits a harsh bump or slipping sensation.
- Affected Vehicles: 2011-2013 models.
- Cause: The adaptive shift strategy software in the PCM needs updating.
- Remedy: TSB 13-3-18 (which supersedes TSB 11-12-10) calls for reprogramming the PCM with updated software to improve shift logic.
Issue: Sudden Loss of Reverse, 3rd, and 5th Gears
- Symptoms: Complete loss of Reverse, 3rd, and 5th gears, often accompanied by DTCs like P0756 and P2701.
- Affected Vehicles: 6F50 transmissions across multiple years.
- Cause: According to SSM 45648 and SSM 50861, incorrect machining of the direct clutch cylinder and tone wheel assembly can cause a snap ring to pop out of place, leading to catastrophic internal damage.
- Remedy: This is a major internal failure. The transmission must be removed and rebuilt with a new direct clutch hub and cylinder assembly. In this scenario, replacing the entire transmission is often the most practical solution.
Issue: Intermittent Electrical and Shifting Anomalies
- Symptoms: Transmission slipping, neutral-out, starting in 5th gear, backup camera staying on in Drive, or cruise control dropping out.
- Affected Vehicles: 2009-2011 and some later models.
- Cause: A failing digital Transmission Range (TR) sensor inside the side cover.
- Remedy: Per TSB 13-5-27, replace the digital TR sensor. Note: For 2013 Hybrid models specifically, recall 13C09 was issued for a faulty TR sensor allowing the vehicle to shift out of Park without the brake applied, fixed via a PCM software update.
What Fails at Every Mileage Band
Pro Tip: The mileage bands below describe what typically fails on used replacement units of that mileage. The checklists provided are things to do WHILE INSTALLING the purchased engine or transmission, not maintenance for your current unit.
Under 60,000 Miles
Early failures are uncommon but can occur. Issues are often electronic or software-related rather than hard part failures. Harsh or delayed shifting may be addressed by a PCM/TCM software update as noted in TSBs. Firm or delayed shifts with no diagnostic codes can be an early sign of solenoid body issues.
- ✓Do during install (recommended): Solenoid Body / Lead Frame: While not mandatory, if the budget allows, replacing the solenoid body is strong preventative medicine against future electronic failures, which are a known weak point.
- ✓Do during install (recommended): Input and Output Speed Sensors (TSS/OSS): These sensors are a frequent failure point on earlier 6F50 models and can cause sudden shifting problems or a no-move condition. They are relatively inexpensive and accessible during replacement.
- ✓Do during install (required): Standard Consumables: Always replace all required seals (axle, torque converter), gaskets, and use fresh MERCON LV fluid.
60,000 - 100,000 Miles
Solenoid body failure causing firm, delayed, or harsh shifts is a common issue in this range. Torque converter shudder or failure also begins to appear. Input/Output Speed Sensor (TSS/OSS) failure can lead to erratic shifting, a wrench light, and potential no-move conditions. Internal seal wear can lead to pressure loss and affect shift quality.
- ✓Do during install (required): Replace the solenoid body (lead frame) if installing a used unit in this mileage range. It is the most common failure point.
- ✓Do during install (recommended): Replace the torque converter. A remanufactured torque converter is a wise investment as shudder and clutch failure are known issues.
- ✓Do during install (required): Standard Consumables: Replace all seals, gaskets, and perform a complete fluid exchange with MERCON LV after flushing the cooler.
100,000 - 150,000+ Miles
Mechanical hard part failures become more likely, including worn clutch packs and valve body issues. Torque converter clutch failure is a significant risk at this mileage. There is a continued risk of solenoid body and speed sensor failures if they haven't been replaced already. Hard shifting between gears (e.g., 35-55 mph) and sputtering or lack of acceleration from a stop are common complaints.
- ✓Do during install (required): Replace the torque converter and solenoid body. Do not reuse these from a high-mileage core.
- ✓Do during install (recommended): A valve body zip kit (like those from Sonnax) can restore hydraulic integrity by addressing wear in the valve body bores, which is common at this mileage.
- ✓Cheap insurance while the engine is out: Inspect/Replace clutch packs and seals if the budget allows for a more thorough rebuild, as these are known wear items.
Real Owner Experiences
| Source | Mileage | What Happened | Cost |
|---|---|---|---|
| 82,000 | A 2013 MKZ experienced an intermittent 'transmission not in park' error, preventing the car from starting. The owner suspected the range control module. The issue also occurred at low speeds. | Not specified | |
| Kelley Blue Book Review | 35,000 | Owner reported the transmission was replaced at 35k miles. They still experienced jerking shifts from 1st to 2nd and 2nd to 3rd. | Not specified, likely warranty |
| Blue Oval Forums | 7,000 | Owner had harsh engagements into Drive and Reverse on a 2.0L model. Dealer wanted to overhaul the transmission to replace a forward clutch piston seal per SSM 44760 (for the 6F35, but illustrates similar family issues). | Not specified, likely warranty |
| Ford Truck Enthusiasts Forums | 77,000 | A 2008 Ford Edge (same 6F50 family) exhibited a 'reverse clunk' since 77k miles. At 100k miles, it developed firmer shifts and downshifting issues, suspected to be the solenoid valve body. | N/A |
| CarComplaints.com | 103,270 | A 2013 Lincoln MKZ failed to shift into drive, displaying a 'shifter system failure' warning light. | N/A |
| BobIsTheOilGuy Forums | 150,000 | A Ford Flex with a 6F55 transmission experienced a torque converter clutch failure. | N/A, owner swapped in a used transmission |
| CarComplaints.com | 186,000 | A 2013 MKZ exhibited hard shifts from Park to Drive and while in motion, followed by sputtering and improper gear shifting. | N/A |
Repair or Replace?
Deciding whether to repair your existing transmission or replace it entirely depends on the symptoms and the extent of the internal damage.
When Repair Makes Sense
- Faulty Transmission Range (TR) Sensor or Solenoid Body/Pack: Typical repair cost is $600 - $1,500. This is a viable repair when the transmission is otherwise shifting smoothly and not showing signs of internal mechanical failure like slipping or grinding. The repair involves replacing electronic components, not rebuilding the transmission itself.
- Minor Leaks from Pans or Seals: Typical repair cost is $150 - $500. If the transmission is not losing a significant amount of fluid and is not damaged from running low on fluid, replacing gaskets or seals is a cost-effective repair.
When Replacement is Smarter
Replacement is the smarter option when the vehicle experiences sudden loss of multiple gears (like Reverse, 3rd, and 5th), indicating a severe internal mechanical failure such as the direct clutch cylinder. It is also the recommended path for high-mileage units with multiple symptoms like slipping, harsh shifting, and diagnostic trouble codes pointing to major internal wear. Given the high labor cost to simply remove and reinstall the transmission, putting that money towards a warrantied used or remanufactured unit is often a better long-term investment than attempting a costly internal rebuild on a failed unit.
Questions to Ask Your Installer
- Have you worked on the Ford 6F50/6F55 transmission before?
- Will you be photographing the solenoid strategy tag on the replacement unit for programming?
- Do you have the proper Ford-specific scan tool (like Ford IDS or FORScan) to program the new solenoid body ID and strategy into the PCM?
- Does your quote include performing the TCM Adaptive Relearn drive cycle after the installation?
- What brand and type of transmission fluid will you be using? (Verify it is Motorcraft MERCON LV).
- Does your process include a mandatory flush of the transmission cooler and lines before installing the new unit?
- How will you verify the torque converter is fully seated before mating the transmission to the engine?
- Does the quoted price include the necessary 10-11 quarts of MERCON LV fluid, new axle seals, and any required gaskets?
Replacement Cost Comparison
The cost to replace a 6F50 transmission varies significantly based on the type of part used. The estimates below do not include taxes or shop supply fees.
| Part Type | Estimated Cost (Part Only) | Notes |
|---|---|---|
| New OEM | $3,100 - $4,500+ | A brand new unit from Lincoln. This part may be superseded by a remanufactured unit from the dealer. |
| Remanufactured OEM | $2,600 - $3,900 | Remanufactured by Ford to original specifications, often with updated parts. Typically includes a core charge of around $1,000. |
| Used OEM | $650 - $1,300 | A salvaged unit from a donor vehicle. Price depends on mileage and condition. |
| Installation Labor | $1,000 - $1,890 | Represents an estimated 8.0 to 10.5 hours of shop time. This includes programming and fluid fill. |
Freight and Delivery Reality
If you are purchasing a used or remanufactured 6F50 transmission online, it will not arrive in a standard cardboard box via regular mail. This is a heavy industrial component.
- Shipping Method: The assembly ships as Less-Than-Truckload (LTL) freight on a wooden pallet. It is NOT a parcel.
- Weight and Dimensions: The un-crated transmission weighs approximately 208 lbs and measures roughly 44" x 24" x 24".
- Delivery Requirements: Because of the weight, delivery to a residential address will require a truck equipped with a liftgate. Delivery to a commercial address with a forklift or loading dock is highly recommended and often cheaper.
- Inspection: You must inspect the transmission for physical damage (like cracked aluminum cases or broken sensors) before signing the driver's delivery receipt.
What is Included and Excluded
When buying a used transmission from a professional auto recycler, expect the following:
- Included: Main aluminum transmission case, all internally lubricated parts (gears, shafts, clutches, internal oil pump), transmission oil pan and side control cover, torque converter, and internal solenoid body (solenoid block/lead frame assembly).
- Not Included: External sensors (unless integrated), external wiring harnesses, shifter linkage, cables, or brackets, engine flexplate/flywheel, transmission cooler lines, and the Transmission Control Module (TCM).
Installation and Programming: Critical Steps
Installing a replacement 6F50 transmission is a complex job for advanced technicians. The DIY difficulty is rated as Advanced/Expert. Several steps are mandatory to prevent immediate failure of the new unit.
Required Tools
This job requires specialized equipment, including an engine support bar, a transmission jack, subframe alignment pins, a torque wrench, and an OBD2 scan tool with Ford-specific programming capabilities (such as Ford IDS or FORScan).
Programming is Not Optional
The transmission contains a solenoid body with a unique calibration. After installation, this information must be programmed into the vehicle's main computer. This process is known as a TCM Adaptive Relearn & Solenoid Strategy Programming (Transmission Characterization Update).
Pro Tip: Before installing the transmission, take a clear photo of the white barcode tag on the top of the case. This tag contains the 13-digit Solenoid Strategy and 7-digit Solenoid Body ID numbers required for programming. The tag is impossible to see once the transmission is in the vehicle.
Failure to program the new solenoid information can cause severe shifting problems and immediate clutch damage. This procedure requires a dealer-level tool and cannot be skipped.
Warning: Do not reuse the solenoid strategy from the old transmission. The calibration is unique to each solenoid body. Using the old data with the new hardware will result in poor performance and likely failure.
Torque Converter Installation
Warning: The torque converter must be fully seated into the transmission's front pump before the transmission is bolted to the engine. To do this, you must push and rotate the converter until you feel three distinct "clicks" or drops. If it is not fully seated, tightening the bellhousing bolts will crack the front oil pump, causing a catastrophic, non-warrantable fluid leak and total transmission failure.
Required Fluids and Parts
When installing a replacement transmission, several other components must be replaced to ensure a successful repair.
- Transmission Fluid: Use only Motorcraft MERCON LV Automatic Transmission Fluid. DO NOT use other types like Mercon V, Dexron VI, or generic multi-vehicle fluids. You will need 9.5 to 11.0 quarts for a full fill (keep 10-11 quarts on hand).
- Seals: Always replace the front axle (half-shaft) seals and the torque converter input shaft seal (OEM Part Number: 7T4Z-7A248-A).
- Gaskets: A new plastic side cover (main control cover) gasket and transmission pan gasket are recommended.
Warning: The transmission cooler and lines must be flushed with a high-pressure solvent before connecting them to the replacement transmission. Debris from the previous transmission failure will contaminate the new unit and cause immediate damage if not completely removed.
Fluid Level Checking
The fluid level must be checked via the dipstick/fill plug with the fluid strictly between 180°F and 200°F (82°C to 93°C) while the engine is idling on a level surface after cycling through all gears.
Expected Service Life and Maintenance
With proper maintenance, the 6F50/6F55 transmission can last well over 150,000 to 200,000 miles. There are anecdotal reports of these transmissions reaching over 350,000 miles with diligent fluid changes. However, many owners experience issues between 75,000 and 150,000 miles, often related to electronics or the torque converter.
Regular transmission fluid changes are critical to extending the life of the 6F50. While Ford has a long service interval, many technicians and knowledgeable owners recommend a drain-and-fill every 20,000 to 30,000 miles, as the MERCON LV fluid darkens quickly. Since the internal filter is considered non-serviceable without a full teardown, frequent partial fluid changes are the best way to keep the fluid clean and protect internal components like the solenoid body and torque converter from contaminated fluid.
Frequently Asked Questions (FAQ)
Can I use a transmission from a Ford Edge or Taurus with the same engine?
No. While other Ford models used the 6F50 transmission, the internal calibrations, wiring, and software are specific to the Lincoln MKZ. Using a transmission from another model will likely result in electronic and shifting problems.
Do I have to program the replacement transmission?
Yes, programming is mandatory. The unique 7-digit Solenoid Body ID and 13-digit Strategy from the replacement unit must be entered into the vehicle's Powertrain Control Module (PCM) to ensure correct shift pressures and timing. Skipping this step will lead to poor shift quality and can cause premature failure.
What is the correct fluid for the 2013 MKZ 3.7L transmission?
The required fluid is Motorcraft MERCON LV. Using any other type of fluid, including Mercon V or multi-vehicle ATF, can cause damage to the clutches and seals.
Is it okay to skip the transmission cooler flush?
No. Flushing the cooler is a critical step. Metal shavings and clutch material from the old, failed transmission get trapped in the cooler. If not flushed, this debris will circulate into the replacement transmission as soon as the engine starts, causing immediate and severe damage that is not covered by warranty.
What tools are required to install this transmission?
Due to the transverse mounting, you will need an engine support bar to hold the engine in place while the subframe is lowered. You will also need a transmission jack, subframe alignment pins, a torque wrench, and an OBD2 scan tool with Ford-specific programming capabilities (like Ford IDS or FORScan) to complete the installation and programming.
How do I check the fluid level on the 6F50?
The fluid level must be checked via the dipstick/fill plug. The fluid temperature must be strictly between 180°F and 200°F (82°C to 93°C). The vehicle must be idling on a level surface after you have cycled the shifter through all gears.
Helpful Videos
Technical Specifications
OEM Part Numbers: DA8P-PA DA8P-PB DA8P-7000-PA DA8P-7000-PB DA8Z-7000-P
Model: 6F50 / 6F55; Type: 6-Speed Automatic; Drivetrain: Front-Wheel Drive (FWD); Mounting: Transverse; Engine Compatibility: 3.7L Duratec V6 (VIN 8th Digit 'K'); Door Jamb Code (TR): J; Fluid Type: Motorcraft MERCON LV; Fluid Capacity: 9.5 - 11.0 quarts; Weight: Approx. 208 lbs
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Lincoln MKZ:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Vehicle and Transmission Identification
- What It Does NOT Fit
- Common Failure Symptoms
- Diagnostic Flowchart
- Known Issues, Bulletins, and Recalls
- Issue: Unexpected Shift to Park Below 5 MPH
- Issue: Sluggish Acceleration from a Rolling Stop
- Issue: Sudden Loss of Reverse, 3rd, and 5th Gears
- Issue: Intermittent Electrical and Shifting Anomalies
- What Fails at Every Mileage Band
- Under 60,000 Miles
- 60,000 - 100,000 Miles
- 100,000 - 150,000+ Miles
- Real Owner Experiences
- Repair or Replace?
- When Repair Makes Sense
- When Replacement is Smarter
- Questions to Ask Your Installer
- Replacement Cost Comparison
- Freight and Delivery Reality
- What is Included and Excluded
- Installation and Programming: Critical Steps
- Required Tools
- Programming is Not Optional
- Torque Converter Installation
- Required Fluids and Parts
- Fluid Level Checking
- Expected Service Life and Maintenance
- Frequently Asked Questions (FAQ)
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