P1744: How to Diagnose & Fix — Torque Converter Clutch System Performance
4 vehicles · 2 makes · $25-$3,800 repair
How to diagnose and fix P1744: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Ford Windstar · 1996–2003
The Ford Windstar equipped with the AX4S (1995-2000) and AX4N/4F50N (2001-2003) automatic transmissions suffers from widespread premature transmission failure. CarComplaints.com records 140 complaints for the 2000 model year alone, and 166 problems for the 2003 model year, making transmission failure the single most reported problem for the Windstar. The AX family of transmissions in the Windstar struggles with lubrication problems, harsh 1-2 and 2-1 gear changes, torque converter clutch issues, and catastrophic internal failures. The torque converter clutch solenoid is a particularly weak point, causing shuddering and codes P0741 and P1744. Average repair cost is $2,190 at 102,200 miles according to CarComplaints.com data. Many owners report needing a complete transmission replacement or rebuild, with costs ranging from $1,750 to $3,100.
Common Symptoms
- Harsh or jerky 1-2 and 2-1 gear shifts
- Transmission slipping or shuddering during acceleration
- Torque converter shudder at 40-55 mph
- Check engine light with transmission codes
- Delayed engagement when shifting from Park to Drive
- Transmission overheating warning
- Complete loss of forward gears
- Grinding or whining noise from transmission
How to Fix
For TCC shudder only (codes P0741/P1744), start with transmission fluid change and TCC solenoid replacement ($400-800). For complete transmission failure, remanufactured transmission replacement is the most common solution ($1,750-2,500 installed). Jasper and Ford Motorcraft remanufactured units are the most commonly recommended. Rebuild is an option at $2,000-3,100 but ensure the torque converter is also replaced. Preventive: change transmission fluid every 30,000 miles - the Windstar transmission runs hot and degrades fluid rapidly.
Sources for this issue (1)
Ford Aerostar · 1990–1997
The Ford A4LD 4-speed automatic transmission used in early Aerostars (and the 4R44E/4R55E in later models) is known as one of Ford's weakest automatic transmissions. The overdrive band and servo fail prematurely, causing loss of overdrive. The forward clutch pack also wears rapidly, causing no-drive conditions. The valve body develops wear in the separator plate, causing erratic shifting. The transmission was originally designed for the lighter Ranger and is marginal for the heavier Aerostar, especially the AWD version.
Common Symptoms
- No overdrive gear — engine revs high on highway
- Delayed or flared 2-3 upshift
- Transmission slipping under load or on hills
- Harsh engagement when shifting from Park to Drive
- Check engine light with TCC-related codes
How to Fix
A complete transmission rebuild with upgraded friction materials, a wider overdrive band, and a TransGo SK-A4LD shift kit is the recommended fix. The shift kit improves clutch apply pressure and corrects valve body issues. For AWD models, consider upgrading to a remanufactured 4R55E with hardened input shaft. Regular fluid changes every 30,000 miles with Mercon V dramatically extends A4LD life.
Sources for this issue (2)
Mazda 626 · 1993–1997
The Ford-designed CD4E automatic transaxle fitted to 1993-1997 (5th-gen GE) 626s with an automatic is one of the most notorious weak points of the car. It runs hot, has undersized clutch packs and a fragile forward-clutch/valve-body design, and commonly fails anywhere from 60,000-100,000 miles. Both the FS 2.0L I4 and KL 2.5L V6 automatic cars used it. Repair shops have reported very high failure rates and the NHTSA/CarComplaints logs are dominated by transmission complaints for these years. A primary root cause was an inadequate factory transmission cooling circuit (a poorly designed radiator that did a bad job cooling the ATF). There was no recall, so owners bore the cost. The 626/MX-6 community regards a manual-transmission car as far more reliable.
Common Symptoms
- Overdrive (O/D OFF) light flashing
- Slipping between gears
- Failure to shift 3rd to 4th
- Harsh or erratic shifting
- Delayed engagement into drive/reverse
- Complete loss of forward drive
- Transmission fluid leaks
- Overheating fluid / burnt smell
How to Fix
Preventatively, service the fluid every 30k miles with the correct spec fluid and add an auxiliary transmission cooler; heat is the primary killer. Once slipping, flashing O/D light, or harsh/erratic shifting begins, a proper rebuild with an upgraded/updated valve body and clutch parts (or a quality remanufactured unit) is the accepted repair. A band-aid fluid change rarely saves a unit that is already slipping.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Valvoline MERCON V automatic transmission fluid, 1 quartOEMValvoline 896421
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (4)
Ford Explorer · 1991–1999
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P1744 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1744 mean?
P1744 stands for "Torque Converter Clutch System Performance." This transmission code means the torque converter clutch (TCC) system is not performing as expected — the lockup clutch inside the torque converter is slipping or not engaging and disengaging properly. The TCC mechanically links the engine to the transmission at cruising speeds to improve efficiency, and the computer monitors slip between engine and transmission speeds to verify it. Excess slip or improper engagement sets this code. You may feel shuddering, RPM that won't settle at cruise, or reduced fuel economy.
What are the most common causes of P1744?
The most common causes of P1744 are: Worn or failing torque converter / lockup clutch, Faulty TCC solenoid, Low or degraded/contaminated transmission fluid, Dirty valve body or stuck valve affecting TCC apply, Damaged TCC solenoid wiring or connector, Internal transmission wear causing excess slip, Faulty transmission control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P1744?
Repair costs for P1744 range from $25 to $3,800, depending on the vehicle and root cause.
Which vehicles are affected by P1744?
Au7o has documented P1744 across 4 vehicle models from 2 manufacturers: Ford, Mazda.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.