Engine & Drum Speed Slippage

DRUM SPEED SLIPPAGE

Gear	Conditions	Drum RPM 1000 with MPH@	Drum RPM 2000 with MPH@	Drum RPM 3000 with MPH@	Drum RPM 4000 with MPH@	Action To Take
1st	L Range, Manual Mode	7	11	20	27	Inspect low and reverse clutch.
1st	O/D Range, Normal Mode	7	11	20	27	Inspect one-way clutch.
2nd	D Range, Manual Mode	20	25	37	50	Inspect 2-4 band.
3rd	O/D Range, Manual Mode	19	38	57	76	Inspect coasting clutch.
O/D	O/D Range, Normal Mode	27	55	81	109	Inspect 3-4 clutch.

ENGINE SPEED SLIPPAGE

Gear	Conditions	Engine RPM	Engine RPM	Engine RPM	Engine RPM	Action To Take
O/D	O/D Range, Normal Mode, Lockup	1000	2000	3000	4000	Inspect torque converter.

Fig 1: 4EAT Downshift Symptom Chart

Courtesy of FORD MOTOR CO.

Fig 2: 4EAT Upshift Symptom Chart

Courtesy of FORD MOTOR CO.

Fig 3: 4EAT Shift Quality Symptom Chart

Courtesy of FORD MOTOR CO.