E 350 Van L6-300 4.9L VIN E 1-bbl (1982)
result in a repeat service.
^
Check torque on valve body bolts.
^
Check to see if main control gasket is blocking an orifice.
^
Check for nicks or porosity in the case passages (valve body to case mating surface).
^
Check the direct clutch piston check ball for leakage
-
inspect the piston check ball for freedom of movement. Improper seating of check ball will cause leakage. Leakage can be detected by turning
the piston upside down (flat side of piston facing you) allowing the check ball to seat in the piston. Pour a small quantity of solvent over the
check ball. If solvent drops past the check ball, replace the piston.
^
Inspect the output shaft feed passages and the cup plug for leakage. Apply 5-10 psi air to the output shaft feed passages. Refer to the AOD
operation and diagnosis guide (course 1720-001) p. 32 for location of the feed passages. If air comes out the wrong feed passage, replace the
output shaft.
^
Check direct clutch piston seal rings (inner and outer) for leakage.
^
Check all direct clutch output shaft seals for freedom of movement and for metal shavings and burrs between seal and output shaft.
^
Check the direct clutch cylinder for groove marks on the rear ID of the drum. Groove marks indicate the small cast iron seal rings are turning with
the output shaft and grooving the cylinder. Groove marks may be caused by contamination or burrs in the output
shaft ring groove causing the seal rings to turn with the output shaft. Visually check the output ring grooves carefully. Replace as necessary the output
shaft, the seal rings and the cylinder.
No 3-4 Upshift With Direct Clutch Pressure Less Than 15 PSI (Indicates No Leakage In The Direct Clutch Circuit) Diagnostic Procedure
^
Clean the valve body. Check for sticking valves as follows: Overdrive servo regulator valve; 3-4 shift valve; 3-4 TV modulator valve; orifice
control valve. If any valves are sticking and they cannot be freed, replace valve body.
^
Reduce valve body bolt torque to minimum side of specification 80 in.lbs.
^
Check the fit of the governor counterweight on the output shaft. If the fit is sloppy, replace the counterweight.
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Check the governor to output shaft retaining ring to make sure it is properly seated on the output shaft. Service as necessary.
^
Check last two large seal rings on the output shaft (#9, #10). They should move freely. Check for metal shaving contamination or burrs between
the seal and output shaft. Replace as necessary.
^
Check the seal ring bore at the rear of case for scoring. Light scoring is permissable. Deep grooving indicates case wear. Replace case for deep
grooving.
Slipping 4th Gear Diagnostic Procedure
NOTE:
Burnt overdrive band will help confirm leakage in the overdrive circuit. Replacing only the overdrive band without finding the cause will result
in a repeat service. If the overdrive band is not burnt, the converter damper/hub weld has usually been found to be suspect.
^
Check overdrive servo cover O-rings and servo piston seal for possible leakage. Replace O-rings and seal if leakage is evident.
^
Verify the overdrive servo cover is not cracked/porous. Coat cover with fluid. Apply air to overdrive servo, apply passage using tool (T80L-
77030-B). Observe to see if air bubbles are present on overdrive servo cover. Replace cover if air bubbles are present.
^
Check the overdrive servo case apply passage to see if it is blocked. Air pressure test. Replace case if necessary.
^
Verify the overdrive servo piston is seated correctly to the band end seat.
^
Verify the overdrive band is seated correctly to anchor pin.
^
Check the torque converter for damper/hub weld
failure. Perform converter damper/hub assembly weld check procedure. Refer to Shop Manual, Section 17-01. Use special service tools T83L-7902-
A.
Replace converter if shaft turns more than two degrees or if there is a grinding noise while applying 50 ft.lbs. torque.
^
Check splines on both ends of the direct driveshaft and in direct clutch cylinder for distortion.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"
