TCI Transmission Gearing Ratios

Navigating the TCI Transmission Gearing Ratios page is easy. Simple view the chart below for your desired transmission and view the Gearing Ratios.

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Transmission	1st	2nd	3rd	4th
GENERAL MOTORS
Powerglide (OEM)	1.76	1.00	N/A	N/A
Powerglide (OEM)	1.82	1.00	N/A	N/A
Powerglide (TCI)	1.65	1.00	N/A	N/A
Powerglide (TCI)	1.80	1.00	N/A	N/A
Powerglide (TCI)	1.92	1.00	N/A	N/A
Powerglide (TCI)	1.98	1.00	N/A	N/A
TH350 (OEM)	2.52	1.52	1.00	N/A
TH350 (TCI)	2.75	1.52	1.00	N/A
TH400 (OEM)	2.48	1.48	1.00	N/A
TH400 (TCI)	2.10	1.40	1.00	N/A
TH400 (TCI)	2.75	1.57	1.00	N/A
TH400 (TCI)	2.97	1.57	1.00	N/A
200-4R (OEM)	2.78	1.57	1.00	0.67
TH700R4/4L60E/4L65E (OEM)	3.06	1.63	1.00	0.70
4L80E/4L85E (OEM)	2.48	1.48	1.00	0.75
4L80E/4L85E (TCI)	2.75	1.57	1.00	0.75
4L80E/4L85E (TCI)	2.97	1.57	1.00	0.75

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Transmission	1st	2nd	3rd	4th
FORD
C4 (OEM)	2.46	1.46	1.00	N/A
C6 (OEM)	2.46	1.46	1.00	N/A
C6 (TCI)	2.72	1.54	1.00	N/A
AOD (OEM)	2.40	1.47	1.00	0.67
AODE-W/4R70W (OEM)	2.84	1.55	1.00	0.70

Transmission	1st	2nd	3rd	4th
CHRYSLER
TF-904 (OEM)	2.45	1.45	1.00	N/A
A-500/42RH (OEM)	2.74	1.54	1.00	0.69
TF-727 (OEM)	2.45	1.45	1.00	N/A
A-518/618/47RH (OEM)	2.45	1.45	1.00	0.69

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Powerglide Planetary Low Gear Ratios

The Powerglide planetary is referred to as a compound gear set with a ring gear. Figure 1 demonstrates the various elements of this planetary.

FIGURE 1

When the transmission is in low gear, the BAND is holding the HIGH GEAR DRUM stationary which also means that SUN GEAR S1 (flange gear) is stationary. Input is provided through sun gear S2 (center gear). This input is transmitted to PINION GEAR P2/P3 then to pinion gear P1 (auxiliary gear). Since S1 is being held, P1 is driven around S1 along with the carrier and OUTPUT SHAFT. The ratio at which the INPUT SHAFT turns compared to the OUTPUT SHAFT can be determined as follows:

Ratio = 1 + [(P2/P3)(S1/S2)] Gear tooth counts for the ratios offered by TCI® are as follows:

RATIO	S1	S2	P2	P3
FORMULA: RATIO = 1 + [(P2/P3)(S1/S2)]
1.58	22	38	18	18
1.76 (OEM)	26	34	21	21
1.821 (OEM)	23	28	18	18
1.80	20	25	16	16
1.98	20	23	18	16

PLEASE NOTE: Stamped type carrier, uses 12 5/8" input shaft.