Most people who use their vehicles off road realize when they have gearing issues and have some idea of how to fix them. Generally, they also have some idea of what options are available that may address the problem. Unfortunately, due lack of machanical expertise, market product hype, unreliable word of mouth or just plain wive's tales, they have no real idea of what effect a change or a particular product will have in a way that they can compare it to a similar change or product.
What we've tried to do below is compile a list of common changes around the products available and modifications possible for the Montero Sport 5-speed and show the effect they have in a way that direct comparisons are possible. To make any comparison valid, data such as tire size, transmission ratio and axle gear ratio are kept consistant.
Obviously, not everyone's vehicles are identical. To generate these same tables based on your vehicle's configuration, click on Calculate your crawl speed.
Factory Mitsubishi transfer case 1.92:1
Engine
Crawl RPM
1000
Tires
Diameter (inches)
35
Gears
Transmission 1st gear
3.91
Transfer case LO gear
1.92
Crawl box LO gear
n/a
Axle gear
5.38
Results
Crawl speed
ft/min
226.86
ft/sec
3.78
in/sec
45.37
Crawl ratio
40.4:1
Mark's 4wd Adapters transfer case 2.85:1
Engine
Crawl RPM
1000
Tires
Diameter (inches)
35
Gears
Transmission 1st gear
3.91
Transfer case LO gear
2.85
Crawl box LO gear
n/a
Axle gear
5.38
Results
Crawl speed
ft/min
152.83
ft/sec
2.55
in/sec
30.57
Crawl ratio
60.0:1
B4R crawl box 2.72:1/NP231J transfer case 2.72:1
Engine
Crawl RPM
1000
Tires
Diameter (inches)
35
Gears
Transmission 1st gear
3.91
Transfer case LO gear
2.72
Crawl box LO gear
2.72
Axle gear
5.38
Results
Crawl speed
ft/min
58.87
ft/sec
0.98
in/sec
11.77
Crawl ratio
155.6:1
B4R crawl box 2.72:1/Terra Low231 transfer case 4:1
