| Tranny | 1st | 2nd | 3rd | 4th | 5th | Rev | Models |
| AX-5 | 3.93 | 2.33 | 1.45 | 1.00 | .85 | 4.74 | 87-98 YJ,TJ,XJ (small engines) |
| AX-15 | 3.83 | 2.33 | 1.44 | 1.00 | 0.79 | 4.22 | 89-98 YJ,TJ,XJ (4.0L engines) |
| BA 10/5 | 3.39 | 2.33 | 1.44 | 1.00 | 0.79 | mid 87-89 YJ's | |
| NP435 | 6.69 | 1.00 | 6.69 | ||||
| NV3550 | 4.04 | 2.33 | 1.38 | 1.00 | 0.78 | 3.75 | Some TJ's |
| NV4500 | 6.34 | 3.44 | 1.79 | 1.00 | 0.73 | 5.61 | |
| SM420 | 7.05 | 3.57 | 1.70 | 1.00 | 7.05 | ||
| SM465 | 6.54 | 3.57 | 1.57 | 1.00 | 6.54 | ||
| SR-4 | 4.07 | 2.39 | 1.49 | 1.00 | 3.95 | 80-81 CJ's 4cyl (some 6cyl) | |
| T-4 | 4.03 | 2.37 | 1.50 | 1.00 | 3.76 | Some 82-86 CJ's | |
| T-5 | 4.03 | 2.37 | 1.50 | 1.00 | 0.86 | 3.76 | Some 82-86 CJ's |
| T-14 | 3.10 | 2.61 | 1.00 | 3.10 | Some 67-75 CJ's | ||
| T-15 | 3.00 | 1.83 | 1.00 | 3.00 | 72-75 CJ's with a V8 | ||
| T-18 | 4.02 | 2.41 | 1.41 | 1.00 | 4.73 | Some 71-79 CJ's | |
| T-18A | 6.32 | 3.09 | 1.69 | 1.00 | 7.44 | Some 76-79 CJ's | |
| T-84 | 2.94 | 1.94 | 1.00 | Willy's MB and Ford GPW | |||
| T-86 | 2.80 | 1.69 | 1.00 | 3.80 | 60's CJ's with the Buick V6 | ||
| T-90 | 2.98 | 1.66 | 1.00 | 45-71 CJ's | |||
| T-98 | 6.40 | 3.09 | 1.69 | 1.00 | Some 55-70 CJ's | ||
| T-150 | 2.99 | 1.75 | 1.00 | 3.17 | Some 76-79 CJ's | ||
| T-176 | 3.82 | 2.29 | 1.46 | 1.00 | 3.82 | Some 80-86 CJ's |
If you can help fill in this chart, please email me any information you can, Thanks.
| Transfer Case | Low Range |
| Dana Model 18 | 2.46 |
| Dana Model 20 | 2.02 |
| Dana 300 | 2.62 |
| NP231 | 2.72 |
The ratios listed are stock configurations.
If you can help fill in this chart, please email me any information you can, Thanks.
Crawl Box
If you do not have a Crawl Box, you can leave 'None' selected.
A Crawl Box is defined as a device used to increase your crawl ratio by means not including Transmission, Transfer Case or Final Drive Ratio. A Crawl Box is usually mounted between the transmission and the transfer case, or between the transfer case and the rear axle. If you have two Crawl Boxes (sicko) please multiply the two reduction values together and enter them in the field after selecting 'Other' (i.e. crawl box #1 = 4:1 and crawl box #2 = 3.5:1, enter 14 when prompted)
Final Drive Ratio
This is the ratio of the gears in your axle. For every revolution of a tire, the
drive shaft turns a certain amount of times. For example: If you have 4.56:1 gears, when
your tires turn one full revolution, then your driveshaft turns 4.56 full revolutions.
Tire Diameter
This is defined as the height of your tire, from the ground to it's highest elevation.
Generally, the height indicated on the sidewall is sufficient for these
calculations. (i.e. a 33x12.5x15 tire is 33 inches tall)
Why should you care about all of this?
For the Crawl Ratio (forward and reverse) you would care if you four wheel in rocky, steep terrain. The slower you can go over jagged, bumpy areas, the more likely you will get past without damaging your vehicle. Crawl "movement" is calculated at 750 RPM and is measured in Feet Per Second.
Everyone should be concerned with the Highway Speed results, unless you trailer your four wheeler wherever you go. This computes what speed you would be traveling at with the transmission, final drive ratio and tire size of your choice. Highway speed is calculated at 2000 RPM and is measured in Miles Per Hour.