Jasper Engines & Transmissions incorporates a procedure to fill the Ford 5R55N/S/W transmissions with the correct level of fluid.  

Though the 5R55N, S and W are all similar in design, they each differ in specific areas based on the needs of the transmission’s intended application. However, a common feature is the lack of a dipstick to check fluid levels.

“Some common complaints from customers on these transmissions are generally caused by low fluid levels,” says Craig Leuck, JASPER transmission division manager. “These complaints include gear slippage, ‘neutraling’ when fluid settles to one side of the pan while the vehicle is in a curve — losing forward motion, or general transmission failure.”  

The 5R55N/S/W is intended to hold 12 quarts of transmission fluid. Inside the pan is a tube that determines the level of fluid (see Figure 1).

As the pan is filled, the fluid level will reach the top of the tube, and then will drip down the tube and out of the pan. “This is the visual indication that the pan is full,” adds Leuck. “But at this point, the pan only holds approximately eight quarts.”

“The next step for the technician is to drive the vehicle until transmission fluid temperature reaches 180°,” says Leuck. “This opens up the transmission cooling system, lowering the fluid level in the pan. The technician can then add the remaining four quarts to the transmission.”

JASPER attaches a bright orange sticker on the pan of each 5R55N/S/W (see Figure 2).

This will remind technicians the transmission holds 12 quarts of fluid. Also provided with the transmission is a Technical Bulletin explaining the procedure to properly fill the transmission.  

Courtesy of Jasper Engines & Transmissions, www.jasperengines.com.