Automatic Transmission Oil Filler Tube Assembly and Level Indicator

The transmission oil filler tube assembly used with Ford's C6 automatic transmission is identified by basic part number 7A228. The transmission oil level indicator (dip stick) fits inside the filler tube. The tube includes a mounting bracket to secure the upper end of the tube to the back of the engine, and an o-ring at the bottom to seal the area where it's inserted into the transmission. Two different tubes were used during the course of 1968 - 1970 Mustang 428 CJ production.

Application Engineering Number Service Part Number
1968 - 1969 Mustang 428 CJ C8ZP-7A228-A C8ZZ-7A228-A
1970 Mustang 428 CJ D0ZP-7A228-A D0ZZ-7A228-A

Original 1967 - 1968 C6 tubes were all painted semi-gloss black for factory installation. At the start of the 1969 model year, both the factory-installed tubes and the 1968 service replacement tubes were painted yellow. The 1970 tube is approximately 2" longer at the top (above the mounting tab) than the 1968 - 1969 tube and was painted pink. The 1968 and 1969 tubes are indented slightly approximately 4" down from the top end of the tube.

C8ZZ-7A228-A (Black) C8ZZ-7A228-A (Yellow) D0ZZ-7A228-A
C8ZZ-7A228-A (Black)
(Image courtesy of Paul Byrnes)
C8ZZ-7A228-A (Yellow) D0ZZ-7A228-A

The transmission oil level indicator used with Ford's C6 automatic transmission is identified by basic part number 7A020. The indicator includes a cap to seal the end of the tube when installed and a chrome handle.

Application Engineering Number Service Part Number
1966 - 1969 Fairlane/Mustang/Torino All C6OP-7A020-B C6OZ-7A020-B
1970 Mustang 428 CJ D0ZP-7A020-A D0ZZ-7A020-A

There are some noticeable differences between the indicators:

Not all indicators are marked with an engineering number. We're not sure why that is or if there's a pattern to explain why. The C6OP-B indicator is approximately 19 3/4" long as measured from the end of the tip to just under the cap.

C6OP-7A020-B C6OP-7A020-B C6OP-7A020-B

The D0ZP-A indicator is approximately 23" long. Both indicators have a slight twist about 8" from the bottom.

D0ZP-7A020-A D0ZP-7A020-A
D0ZP-7A020-A D0ZP-7A020-A

A version of the C6OP-7A020-B indicator that doesn't include an engineering number is also marked slightly differently at the bottom (images courtesy of Keith Stem; note the absence of holes):

C6OP-7A020-B C6OP-7A020-B
C6OP-7A020-B (alternate) C6OP-7A020-B (cap)

Images courtesy of Tim Griffith unless otherwise noted.