Troubleshooting the automatic transmission is simplified by using the proven method of diagnosis. One of the most important things to remember is that there is a definite procedure to follow. Do not take short cuts or assume that critical checks or adjustments have already been made.

The following procedures are recommended for checking and/or verifying that the various components are adjusted and operating properly. Use Rotunda Automatic Transmission Tester 014-00737 or equivalent. Follow the manufacturer's instructions.

Diagnosis Charts

The following diagnosis charts can be used as an aid in diagnosing the Automatic Overdrive Transmission.

AUTOMATIC TRANSMISSION DIAGNOSIS

Condition	Possible Source	Action
Slow Initial Engagement	Improper fluid level.	Perform fluid level check.
	Damaged or improperly adjusted linkage.	Service or adjust linkage.
	Contaminated fluid.	Perform fluid condition check.
	Improper clutch and band application, or low main control pressure.	Perform control pressure test.
Rough Initial Engagement	Improper fluid level.	Perform fluid level check.
	High engine idle.	Adjust idle to specifications.
	Looseness in the driveshaft, U-joints or engine mounts.	Service as required.
	Improper clutch or band application, or oil control pressure.	Perform control pressure test.
	Sticking or dirty valve body.	Clean, service or replace valve body.
Harsh Engagements—(Warm Engine)	Improper fluid level.	Perform fluid level check.
	TV linkage misadjusted (high TV), disconnected/sticking/damaged return spring disconnected.	Adjust or service TV linkage.
	Engine curb idle too high.	Check engine curb idle.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
No or Delayed Forward Engagement (Reverse OK)	Improper fluid level.	Perform fluid level check.
	Manual linkage—misadjusted/damaged	Check and adjust or service as required.
	Low main control pressure (leakage).	Control pressure test, note results.
	Forward clutch stator support seal rings leaking (No. 3 and No. 4).	Perform air pressure test or visually inspect especially if forward clutch plates are burnt.
	Forward clutch assembly burnt/damaged.	Perform air pressure test or visually inspect especially if forward clutch plates are burnt.
	Forward clutch cylinder check ball leaking/leaking piston seal rings.	Perform air pressure test or visually inspect especially if forward clutch plates are burnt.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
	Transmission filter plugged.	Replace filter.
	Pump damaged/leaking.	Visually inspect pump gears. Replace pump if necessary.
No or Delayed Reverse Engagement (Forward OK)	Improper fluid level.	Perform fluid level check.
	Manual linkage misadjusted/damaged.	Check and adjust or service as required.
	Low main control pressure in reverse.	Control pressure test.
	Reverse clutch or reverse clutch stator support seal rings leaking (No. 1 and No. 2).	Air pressure test or visually inspect, especially if reverse clutch plates are burnt.
	Reverse clutch assembly burnt/worn	Air pressure test or visually inpect, especially if reverse clutch plates are burnt.
	Reverse clutch piston check ball leaking/leaking piston seal rings.	Air pressure test or visually inspect, especially if reverse clutch plates are burnt.
	Valve body bolts loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
	Transmission filter plugged.	Replace filter.
	Pump damaged.	Visually inspect pump gears. Replace if necessary.
No or Delayed Reverse Engagement and/or No Engine Braking in Manual Low (1)	Improper fluid level.	Perform fluid level check.
	Low reverse band burnt/worn.	Perform air pressure test.
	Low reverse servo piston seal leaking.	Air pressure test or visually inspect especially if low reverse band is burnt.
	Planetary low one-way roller clutch damaged.	Replace.
	End-play clearance too tight.	Check transmission end play clearance.
No Engine Braking in Manual Second Gear	Improper band or clutch application, or oil pressure control system.	Perform control pressure test.
	Overdrive servo leaking.	Perform air pressure test of overdrive servo for leakage. Service as required.
	Polished or glazed band or drum	Service or replace as required
Forward Engagement Slips/Shudders/Chatters	Improper fluid level.	Perform fluid level check.
	Manual linkage misadjusted/damaged	Check and adjust or service as required.
	Low main control pressure.	Control pressure test.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
	Forward clutch piston ball check not seating/leaking	Replace forward clutch cylinder. Service transmission as required.
	Forward clutch piston seal cut/worn.	Replace seal and service clutch as required.
	Forward clutch stator support seal rings leaking (No. 3 and No. 4).	Air pressure test especially if forward clutch plates are burnt.
	Low one-way roller clutch (planetary) damaged	Determine cause of condition. Service as required
Reverse Shudders/Chatters/Slips	Improper fluid level.	Perform fluid level check.
	Low main control pressure in reverse	Control pressure test.
	Low reverse servo leaking.	Air pressure test; visually inspect seal rings and piston bore.
	Low (planetary) one-way roller clutch damaged.	Determine cause of condition. Service as required
	Reverse clutch drum bushing damaged.	Determine cause of condition. Service as required
	Reverse clutch stator support seal rings, ring grooves worn/damaged.	Determine cause of condition. Service as required
	Reverse clutch piston seal cut/worn.	Determine cause of condition. Service as required
	Reverse band damaged or incorrect servo piston.	Service as required.
	Looseness in the driveshaft. U-joints or engine mounts.	Service as required.
No Drive, Slips or Chatters in First Gear in D. All Other Gears Normal. First Gear in (D) Automatic Overdrive Transmission	Damaged or worn (planetary) one-way roller clutch.	Service or replace planetary one-way roller clutch.
No Drive, Slips or Chatters in Second Gear	Intermediate friction clutch or one-way roller clutch.	Service as required.
	Intermediate clutch piston bleed hole blocked or not positioned at 12 o'clock.	Clean and install bleed hole at 12 o'clock position.
	Improper band or clutch application, or control pressure	Perform control pressure test.
	Intermediate clutch stackup incorrect.	Check intermediate clutch pack clearance.
	Dirty or sticking valve body	Clean, service or replace valve body.
Initial Drive in Second or Third	Improper band and/or clutch application, or oil pressure control system.	Perform control pressure test.
	Intermediate clutch pack clearance too tight	Check intermediate clutch pack clearance.
	Damaged or worn governor. Sticking governor.	Perform governor check. Replace or service governor, clean screen.
	Valve body loose	Tighten to 9-11 Nm (80-97 lb-in).
	Dirty or sticking valve body	Clean, service or replace valve body.
	Cross leaks between valve body and case mating surface.	Service or replace valve body and/or case as required.

Condition	Possible Source	Action
Shift Points Incorrect	Improper fluid level.	Perform fluid level check.
	TV linkage out of adjustment.	Service or adjust linkage.
	Improper speedometer gear installed.	Replace gear.
	Improper clutch or band application, or oil pressure control system.	Perform shift test and control pressure test.
	Damaged or worn governor.	Service or replace governor—clean screen.
	Dirty or sticking valve body.	Clean, service or replace valve body.
All Upshifts Harsh or Delayed or No Upshifts	Improper fluid level.	Perform fluid level check.
	Throttle linkage—misadjusted (high TV)/ disconnected/sticking/damaged/ return spring disconnected.	Adjust throttle linkage. Service as required,
	Manual linkage—misadjusted damaged.	Check and adjust or service as required.
	Governor sticking.	Perform governor test. Service as required.
	Main control pressure too high.	Control pressure test. Service as required.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
Mushy/Early All Upshifts Pile Up/Upshifts	Improper fluid level.	Perform fluid level check.
	TV throttle linkage misadjusted (low TV) sticking/damaged.	Adjust throttle linkage. Service as required.
	Low main control pressure.	Control pressure test. Note results.
	Valve body bolts loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body valve or throttle control valve sticking.	Determine source of contamination. Service as required
	Governor valve sticking.	Perform governor test. Service as required
No 1-2 Upshift	Improper fluid level.	Perform fluid level check.
	Manual linkage—misadjusted/ damaged.	Check and adjust or service as required.
	Low main control pressure to intermediate friction clutch.	Control pressure test. Note results.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required.
Rough/Harsh/Delayed 1-2 Upshift	Improper fluid level.	Perform fluid level check.
	Poor engine performance.	Tune engine.
	TV linkage—misadjusted (high TV)/damaged. All shifts will be harsh/delayed.	Adjust linkage. Service as required
	Main control pressure too high.	Control pressure test. Note results.
	Governor valve sticking.	Perform governor test. Service as required.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in)
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
Mushy/Early/Soft/Slipping 1-2 Upshift	Improper fluid level.	Perform fluid level check.
	Incorrect engine performance.	Tune adjust engine idle as required.
	TV linkage misadjusted (low TV)/sticking/damaged. All shifts will be affected.	Adjust throttle linkage. Service as required.
	Low main control pressure.	Control pressure test. Note results.
	Valve body bolts loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required.
	Intermediate friction clutch burnt/worn.	Determine cause of condition. Service as required.
	Governor valve sticking.	Perform governor test. Service as required.
No 2-3 Upshift	Improper fluid level.	Perform fluid level check.
	Low main control pressure to direct clutch.	Control pressure test. Note results.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination, then service as required.
	Direct clutch or assembly burnt/worn.	Stall test. Determine cause of condition. Service as required
	Converter damper hub/weld broken.	Perform converter damper hub weld check . Replace torque converter if required.
Harsh/Delayed 2-3 Upshift	Incorrect engine performance.	Check engine tune-up.
	Throttle linkage misadjusted (high TV)/sticking/damaged. All shifts will be harsh/delayed.	Adjust linkage. Service as required
	2-3 accumulator piston—apply passage plugged/omitted.	Remove 2-3 accumulator piston and visually inspect or air test for plugging condition or omission.
	2-3 accumulator piston seals cut/worn.	Replace seals, determine cause of condition. Service as required.
	Damaged 2-3 accumulator.	Service as required.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves. 2-3 capacity modulator valve.	Determine source of condition. Service as required
	TV control cable bent, sticking.	Check cable. Replace as necessary.
Soft/Early/Mushy 2-3 Upshift	TV linkage: misadjusted (low TV)/bent/sticking. All shifts will be soft/early.	Adjust linkage. Service as required
	Valve body bolts loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
	Direct clutch assembly burned/worn.	Stall test. Determine cause of condition. Service as required.
	TV control cable bent, sticking.	Check cable. Replace as necessary.
No 3-4 Upshift (Stays in Third Gear)	Throttle linkage —misadjusted/bent/sticking.	Adjust throttle linkage. Service as required.
	Valve body bolts loose/too tight.	Check torque on valve body bolts. Tighten to 9-11 Nm (80-97 lb-in).
	Direct clutch circuit leakage—Perform Direct Clutch Pressure Test to confirm.	Check for nicks or porosity in the case passages. (Valve body to case mating surface). Replace case for the above.
	NOTE: Burnt direct clutch plates will help to confirm leakage in the direct clutch circuit. Replacing only the plates and not finding the cause will require repeat service.	Direct clutch piston check ball leaking. Perform check ball leakage procedure; found in cleaning and inspection portion. Replace piston if leakage confirmed. Direct clutch piston seal rings (inner and outer) leaking. Replace. Check the direct clutch output shaft seal rings (No. 5, No. 6). They should move freely on the output shaft. Check for metal shaving contamination or burrs between the seal and the output shaft. Replace as necessary. Check the large seal rings on the output shaft for freedom of movement. Check for contamination such as metal shavings on the output shaft. Replace as necessary. NOTE: The four large seal rings are numbered 7, 8, 9 and 10. Seal rings 7 and 8 (closest to the output shaft hub) are for the direct clutch. Seal rings 9 and 10 (closest to the governor) are for the governor. Inspect the output shaft feed passages and the cup plug for leakage.
No 3-4 Upshift (Stays in Third Gear) Continued	Valve body contamination/sticking valves.	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.
	Main control gasket distortion.	Check if main control gasket is blocking an orifice. Replace gasket.
	Case out-of-flat can cause sticking valve.	Reduce valve body bolt torque, tighten to minimum side of specification 9 Nm (80 lb-in).
	Governor leakage.	Check last two large seal rings on the output shaft (No. 9 and No. 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 permissible. Deep grooving indicates case wear. Replace case for deep grooving. Check the governor to output shaft retaining ring to make sure it is properly seated on the output shaft. Service as necessary. Check the fit of the governor counterweight on the output shaft. If the fit is sloppy, replace the counterweight.
Harsh/Delayed 3-4 Upshift	TV linkage—misadjusted/high TV/cable bent/sticking. All shifts will be harsh/delayed.	Adjust linkage. Service as required
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Determine source of contamination. Service as required
	Incorrect engine performance.	Tune/adjust engine as required.

Condition	Possible Source	Action
Slipping Fourth Gear (Engine Flare-Up/No Fourth Gear Drive Capability)	Overdrive circuit leakage or blocked passage. NOTE: Burnt overdrive band will help to confirm leakage in the overdrive circuit. Replacing only the overdrive band without finding the cause will result in a repeat service.	Check valve body bolt torque. Overdrive servo cover seals leaking. Replace seals.
	Overdrive servo piston not applying overdrive band/band not applying.	Overdrive servo piston seal leaking. Replace seal. Overdrive servo rod excessive clearance in case. Replace inoperative/worn parts. Overdrive servo cover cracked/porous. Coat cover with fluid. Apply air to overdrive servo, apply passage using Servo Piston Remover T80L-77030-B or equivalent. Observe to see if air bubbles are present on overdrive servo cover. Replace cover if air bubbles are present Overdrive servo case apply passage blocked. Air pressure test. Replace case if necessary.
	Overdrive band mislocated.	Overdrive servo piston not seated to the band end seat. Service. Overdrive band not seated to anchor pin. Service
	Converter damper plate and hub fracturing the weld and/or rivets fatiguing, or the damper springs breaking.	Perform converter damper/hub assembly weld check procedure. Use Converter Checking Tool T83L-7902-A or equivalent. Replace converter if shaft turns more than two degrees or if there is a grinding noise while applying 50 lb-ft torque.
	Direct driveshaft splines distorted.	Check splines on both ends of the direct driveshaft. Check splines in direct clutch cylinder. Replace direct driveshaft and hardware that splines to it for distortion.
Erratic Shifts	Improper fluid level.	Perform fluid level check.
	Poor engine performance.	Check engine tune-up.
	TV linkage—binding/sticking.	Inspect throttle linkage. Service as required.
	Valve body bolts—loose/too tight.	Tighten to 9-11 Nm (80-97 lb-in).
	Valve body dirty/sticking valves.	Line pressure test, note results. Determine source of contamination. Service as required
	Governor valve stuck.	Perform governor test. Service as required.
	Output shaft collector body seal rings damaged.	Service as required.
Shift 1-3 in D	Intermediate friction clutch burnt/damaged.	Determine cause of conditon. Service as required
	Intermediate one-way roller clutch damaged.	Determine cause of condition. Replace/service as required.
	Improper clutch application, or oil pressure control system.	Perform control pressure test.
	Dirty or sticking valve body	Clean, service or replace valve body.
	Governor valve stuck.	Perform governor test. Service as required.
Engine Over-Speeds on 2-3 Shift	Linkage out of adjustment.	Service or adjust linkage.
	Improper clutch application, or oil pressure control system.	Perform control pressure test.
	Damaged or worn direct clutch.	Perform air pressure test. Service as required
	Dirty or sticking valve body.	Clean, service or replace valve body.
	Converter damper/hub broke.	Perform converter damper/hub weld check. Replace converter if necessary.
Shift Hunting 3-4, 4-3	Poor engine performance—EGR solenoid worn or damaged.	Tune-up engine; replace solenoid.
	Manual linkage misadjusted.	Check and adjust or service as required.
Rough Shudder 3-1 Shift at Closed Throttle in D	Incorrect engine idle or performance	Tune, and adjust engine idle.
	Improper linkage adjustment.	Service or adjust linkage.
	Improper clutch or band application or oil pressure control system.	Perform control pressure test.
	Improper governor operation.	Perform governor test. Service as required.
	Dirty or sticking valve body.	Clean, service or replace valve body.
Rough or Mushy 4-2 or 3-1 Shift (Kickdown)	Incorrect engine performance.	Tune, adjust engine idle as required.
	Improper application of intermediate friction and one-way roller clutch.	Service as required.
	Dirty or sticking valve body.	Clean, service or replace valve body
No Forced Downshifts (Kickdown)	Damaged, misadjusted throttle linkage.	Inspect and adjust throttle linkage.
	Improper clutch or oil pressure control system.	Perform control pressure test.
	Dirty or sticking governor.	Perform governor test. Service or replace governor. Clean screen.
	Dirty or sticking valve body	Clean, service or replace valve body.
Shift Efforts High	Manual shift linkage damaged/misadjusted.	Check and adjust or service as required.
	Inner manual lever nut loose.	Tighten nut to 26-37 Nm (20-27 lb-ft).
	Manual lever retainer pin damaged.	Adjust linkage and install new pin
Transmission Overheats	Improper fluid level.	Perform fluid level check.
	Incorrect engine idle or performance.	Tune or adjust engine idle.
	Improper clutch or band application, or oil pressure control system.	Perform control pressure test.
	Restriction in cooler or lines.	Service restriction.
	Seized converter one-way roller clutch.	Replace one-way roller clutch.
	Dirty or sticking valve body.	Clean, service or replace valve body.
Transmission Clunk or Squawk During 1-2 or 2-3 Shift (AOD)	Intermediate clutch piston bleed hole blocked or not positioned at 12 o'clock.	Clean piston and install bleed hole at 12 o'clock position.
	Anti-clunk spring not positioned.	Secure anti-clunk spring.
	Converter damper spring broken.	Perform converter damper hub weld check.
Transmission Leaks	Case breather vent.	Check the vent for free breathing. Service as required
	Leakage at gasket, seals, etc.	Remove all traces of lube on exposed surfaces of transmission. Check the vent for free breathing. Operate transmission at normal temperatures and perform fluid leakage check. Service as required
Poor Vehicle Acceleration	Poor engine performance.	Check engine tune-up.
	Torque converter one-way roller clutch locked up.	Replace torque converter.
Transmission Noisy—Valve Resonance NOTE: Gauges may aggravate any hydraulic resonance. Remove gauge and check for resonance level.	Improper fluid level.	Perform fluid level check.
	Improper band or clutch application, or oil pressure control system.	Perform control pressure test.
	Cooler lines grounding.	Free up cooler lines.
	Dirty or sticking valve body.	Clean, service or replace valve body.
	Internal leakage or pump cavitation.	Service as required.
Harsh Coasting Downshift Clunk	Anti-clunk spring not seated properly.	Re-position anti-clunk spring properly.
	TV linkage misadjusted (high TV).	Adjust linkage, service as required
Initial Engagement Clunk (Engine Warm) NOTE: Refer to rough initial engagement also.	Engine rpm's above specification	Adjust engine rpm to specification.
	Throttle valve linkage misadjusted (high TV).	Adjust linkage.
	Worn/damaged/loose: —U-joint (front/rear) —Slip yoke —Rear axle —Rear suspension	Service as necessary.
	Excessive transmission end play.	Check transmission end play. Replace selective thrust washer if necessary

 

PINPOINT TEST A: TRANSMISSION NOISY—OTHER THAN VALVE RESONANCE

A1 ROAD TEST

• Drive vehicle to determine if noise level is within acceptable limits.

• Is noise within acceptable limits?

Vehicle OK.

No
GO to A2.

 

A2 PERFORM LINKAGE CHECK

• Check linkage adjustment as outlined.

• Is linkage properly adjusted?

Yes
GO to A3.

No
SERVICE and/or ADJUST linkage. GO to A1.

 

A3 PERFORM FLUID CHECK

• Check fluid for proper level and/or contamination as outlined.

Fluid level correct; No contamination
GO to A4.

Fluid level low; No contamination
FILL transmission until fluid level is between ADD and FULL. GO to A1.

Fluid contaminated
STOP! REMOVE, DISASSEMBLE, CLEAN and SERVICE transmission. FLUSH converter, cooler and cooler lines.

 

A4 STALL TEST

• Perform Stall Test. Check for noise at initial engagement for each gear.

• Can noise be heard in every gear?

Yes
GO to A5.

No
REPLACE planetary gear set.

 

A5 SPEEDOMETER GEAR

• Remove speedometer gear and check for noise.

• Does noise stop?

Yes
REPLACE speedometer gear.

No
CHECK extension housing bushing, seal or driveshaft. SERVICE or REPLACE as necessary. If noise still exists, REPLACE planetary gear set.

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