A/T - C6 Early Shifts, Stacked Shifts, No Upshifts
TRANSMISSION: C6BULLETIN: # 072
SUBJECT: Erratic Shifts
APPLICATION: Ford
DATE: September 1991
C-6 Diesel Shift Complaints
Early shifts, stacked shifts, no upshifts1 etc. can be cause by using the wrong parts or a vacuum regulator that is out of adjustment. Use the following steps to check your work.
(STEP 1)
Make sure you are using a diesel valve body. Figure 1 shows you how to I.D, the valve body.
Note
DO NOT use a valve body kit in a diesel valve body unless the instructions of the kit specify it will work.
(STEP 2)
Make Sure you are using a diesel governor. Figure 2 shows how to I.D. the governor.
The secondary weight should measure .550" on the large land and .450" on the small land. The spring should weigh 2 pounds at .400" height.
(Step 3)
Adjust the vacuum regulator to 11 Hg - 13 Hg. Diesel C-6's do not use 18 Hg of vacuum like gas models, it's important to have the regulator adjusted properly. To adjust the regulator, loosen the holddown bolts and move the regulator body. Figure 3.
(Use 4)
Use a green stripe modulator. P/N D7OZ-7A377A
BULLETIN RECAP
^ Modulator vacuum should be 11Hg - 13Hg at closed throttle
^ Use a green stripe modulator
^ Use a diesel valve body and governor