We carry many speedometer gears for Mopar transmissions. To determine what gear you need, use the table below. Our part #’s for mopar speedometer gears are FD0xx where xx is the tooth count of the gear.
At 60MPH, 1 tooth = 2 – 3mph.
More teeth slow the speedometer down, less teeth raise the the speedometer. Gears with 25 teeth or less require a different speedometer adapter.
Tooth count table is accurate to within 5MPH.
Axle ratio
tire diameter | 2.4 | 2.7 | 2.9 | 3.2 | 3.5 | 3.9 | 4.1 | 4.3 | 4.5 |
23.7 | 27 | 29 | 32 | 35 | 39 | 43 | 45 | ||
24.1 | 26 | 29/28 | 31 | 34 | 39 | 41/43 | 45 | ||
24.6 | 26 | 28 | 31 | 34 | 37 | 41 | 43 | ||
25.1 | 25 | 28 | 30 | 33 | 37 | 40 | 42 | ||
25.6 | 25 | 28 | 30 | 33 | 36 | 40 | 42 | ||
26.1 | 25 | 28 | 30 | 33 | 36 | 40 | 41/42 | 44 | 45 |
26.3 | 24 | 27 | 29 | 32 | 35 | 39 | 41 | ||
26.8 | 24 | 27 | 28 | 32 | 35 | 38 | 40 | ||
27.4 | 24 | 26 | 28 | 31 | 34 | 38 | 39 | ||
27.9 | 26 | 28 | 31 | 33 | 37 | 38 | 41 | 43 | |
28.5 | 25 | 27 | 29/30 | 32 | 35 | 37 | |||
28.9 | 25 | 27 | 29/30 | 32 | 35 | 37 | |||
29.2 | 24 | 26 | 29 | 31 | 35 | 36 | |||
30.0 | 24 | 26 | 29 | 31 | 35 | 36 | 38 | 40 |