The Many Issues With The 4F50N Automatic Transmission
Posted by Regis F. on Thursday, September 12th, 2013
The 4F50N is a four speed automatic trans-axle built by Ford. It is a member of the AXOD family of Ford Transmissions. It was first put into production in 2001 and phased out of production at the end of the 2007 model year. It was used in all Ford brands, including Mercury and Lincoln. It can be found in the Ford Taurus, Windstar and Freestar, the Mercury Sable and Monterey, and the Lincoln Continental.
The 4F50N has some reliability problems that all owners and repair shops should be aware of. Let’s take a look at some of the more common issues.
The 4F50N has problems with internal lubrication. Not all the parts in the transmission will get the proper lubrication required to give them a long lifespan. Regardless of what Ford recommends for service intervals, I recommend that the transmission fluid and filter be changed every 20,000 miles. This will help keep the filter from getting clogged up and further starving the transmission of vital transmission fluid. It is important to actually drop the pan to drain the fluid instead of siphoning it off. Any debris in the pan must be thoroughly cleaned. The valve body should be sprayed down with a Brake Clean type solvent to remove anything that didn’t drain with the oil.
Another very common problem found with this automatic transmission is the failure of the intermediate clutch. When it starts to fail you will notice soft first to second gear shifts. As it gets worse, you will notice the transmission start to slip. When the clutch fails, it fills the filter with debris, which in turn clogs it up and results in the transmission being starved for transmission fluid. At this point the transmission will be most likely destroyed and will require a replacement transmission.
The transmission parking pawl is also subject to failure. This is extremely troubling because it can cause the vehicle to roll away when parked. Many times the failure can be traced back directly to the vehicle owner, who often forgets to apply the parking brake. Without the parking brake on, the load of the vehicle can be too much and break the parking pawl.
There are also plenty of problems with the torque converter. In fact so many complaints have been registered with the NHTSA that they have recently started an investigation of both the Freestar and Monterey that are equipped with this transmission. For more information visit www.nhtsa.gov.