Rock Crawler Gear ratios

[cj!]

Questions often get asked about different gearing options and there seems to be a need for some figures so here is what I have worked out when I was looking at the Sierra t-case to go in my Vit. There may be other ratios available from other manufacturers and if so add please them to this thread. These figures are what I have gained from searching sites and calculating the ratios. There may be errors so confirm for yourself.

High Low
% Ratio % Ratio

Sierra Stock 1.409 2.268

Calmini 4.16: 12.2% 1.58 83.6% 4.16

Calmini 5.14: 18.3% 1.67 127% 5.15

Calmini 6.5: 20.2% 1.69 187% 6.51

Rocky Road 4.16: 12% 1.58 83% 4.16

Rocky Road 6: 24% 1.75 170% 6.12

Rocky Road 8: 24% 1.75 260% 8.16

Trail Tough 4.16: 12% 1.58 84% 4.24

Trail Tough 4.9: 16% 1.63 115% 4.88

Trail Tough 6.4: 17% 1.65 181% 6.37

Rockhopper S4: 24% 1.75 180% 6.35

Trail-Gear 6.5: 20% 1.7 187% 6.5

The above mentioned 'Sierra Stock' ratios of 1.409 and 2.268 only apply to 1300 NT, WT (leaf sprung only). So for those who have 1L, or coilies:

1-litre Sierra Stock (SJ-40): 1.580, 2.511

Coily Sierra Stock (SJ-80): 1.320, 2.123

Jimny

Stock 1.32 high, 2.145 low
Trialjimny gears 1.63 high (23%), 2.64 low (23%)
APIO gears 1.32 High (0%) 3.382 Low (58%)

Trialjimny and APIO gears 1.63 High (23%), 4.169 Low

(these are all with the CHAIN drive t/case )

Vitara

Low range ratio and reduction.

Stock 1.816

Rockhopper 4.16 129%

Rocky Road 4.4 142%

Calmini 4.24 134%

Trail Tough 4.24 134%

High range is 1:1 for all gears as there is no reduction available to the high range.

The crawler gears will fit all Vitara's '91 on and will fit GV's with a 1.6 4cyl auto & manual, 2.0 4cyl auto & manual and 2.5 V6 4 speed auto only.

There is now another option for the Vitara from Trail Tough called the "Undertaker" which is a 1.5:1 permanent underdrive that fits between the trans and the t-case and alters both low and high range.

Here's some gearing calculators.

http://www.izook.com/gearcalc.htm

http://www.novak-adapt.com/knowledge/gearing.htm

http://members.optusnet.com.au/~zerosin/gearcalc.html

[christover1]

There is now another option for the Vitara from Trail Tough called the "Undertaker" which is a 1.5:1 permanent underdrive that fits between the trans and the t-case and alters both low and high range.

I would love one of these.
I think gearing/power band was more of an issue than lack of front locker, on the last trip.
Often had grip, but no power or movement, till I revved the xxxx out of it.
But success at a greater speed than comfortable.
With 31's it would be enough without any transfer gears, and would be more useable on road.
About the same undergearing that Frog was.
Be very little chance of speeding
Could tow a bit easier too.
Now just need to find the umpteen thousand bucks for the job