February 21, 2013
Some common complaints associated with a 5R55N, 5R55W and 5R55S are high TCC slip, slip codes 741, TCC lining degradation, and converter apply or release concerns. These complaints are often caused by wear at the TCC control valve casting bore. Although the control circuits used to stroke the control valve in the 5R55N differ from the 5R55W and 5R55S units, the TCC control valve is the converter oil switch valve, ultimately directing converter apply or release oil in both designs. Sonnax oversized TCC control valve kit 56947J-05K works in the 5R55N, 5R55W and 5R55S, and allows the valve body bore to be refurbished to restore proper TCC modulator/apply circuit fluid pressure control.
The modulator sleeve and inner modulator valve must be inspected for probable bore wear.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.