Forum Discussion
APT
Mar 25, 2015Explorer
3.21 gearing while not ideal is probably fine if he has the 8-spd trans. The first 4 gears align pretty close to an older F-150 4-spd if it had 6.10 axle ratio. I expect that combo would have 5 usable towing gears, maybe 6.
2013 8-spd
4.71 x 3.21 = 15.1191
3.14 x 3.21 = 10.0794
2.1 x 3.21 = 6.741
1.67 x 3.21 = 5.3607
1.29 x 3.21 = 4.1409
1 x 3.21 = 3.21
0.94 x 3.21 = 3.0174
0.67 x 3.21 = 2.1507
7.029850746
Compare that to an old 4-spd with 4.56:
4-spd axle
2.48 x 4.56 = 11.3088
1.56 x 4.56 = 7.1136
1 x 4.56 = 4.56
0.7 x 4.56 = 3.192
or the F-150 6-spd:
6-spd 2009+ axle
4.17 x 3.55 = 14.8035
2.34 x 3.55 = 8.307
1.52 x 3.55 = 5.396
1.14 x 3.55 = 4.047
0.86 x 3.55 = 3.053
0.69 x 3.55 = 2.4495
2013 8-spd
4.71 x 3.21 = 15.1191
3.14 x 3.21 = 10.0794
2.1 x 3.21 = 6.741
1.67 x 3.21 = 5.3607
1.29 x 3.21 = 4.1409
1 x 3.21 = 3.21
0.94 x 3.21 = 3.0174
0.67 x 3.21 = 2.1507
7.029850746
Compare that to an old 4-spd with 4.56:
4-spd axle
2.48 x 4.56 = 11.3088
1.56 x 4.56 = 7.1136
1 x 4.56 = 4.56
0.7 x 4.56 = 3.192
or the F-150 6-spd:
6-spd 2009+ axle
4.17 x 3.55 = 14.8035
2.34 x 3.55 = 8.307
1.52 x 3.55 = 5.396
1.14 x 3.55 = 4.047
0.86 x 3.55 = 3.053
0.69 x 3.55 = 2.4495
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