WHAT, is a stick please ? Do you have a thread on your "Adventure Machine" ?
Going to swap the automatic Ford AOD 4 speed Transmission to a manual Ford ZF5 5 speed Transmission (stick 1), then swapping out the stock Borg Warner 1356 transfer case (has 1 stick) for a NP 208 range box (front half of a NP 208 Transfer case, 1 stick) in front of a modified NP205 transfer case (2 sticks, or more commonly called twin stick). So all in all this gives me 4 sticks, but already had one so only 3 new sticks.
I know you will have more questions Landlubber, but I will try to address the most obvious ones first.
Why swap the 4 speed overdive automatic transmission to a 5 speed overdrive manual transmission? First reason is I like to be able to lock the transmission in the gear I want/need for the given road and engine conditions and while I could put a manual valve body in the automatic transmission there are draw backs such as not able to skip gears fastly. Another reason is the AOD has a first gear ratio of 2.40:1 while the ZF5 has a steep first gear ratio of 5.76:1 ratio (the larger the number the lower the gear, the more torque you put to the ground). Then the AOD has an overdrive ratio of 0.67:1 ratio for overdrive, and the ZF5 Ffith gear is 0.76:1 ratio (the smaller the first number, the more efficient lower the engine rpm to maintain 55 mph = better gas mileage). So the trade off for better fuel economy vs better crawling power won out for me.
Next I talked about range boxes, twin sticks, and transfer cases. All of us here pretty much know what a transfer case does. But just for a refresher :
A transfer case is a case of gears designed to split (or transfer) the power of the engine to both the front and rear of the vehicle. We also know not all transfer cases are createdequal. Some are stronger than others, some of them have low range (some do not), some are full time gear boxes while others are part time (AWD vs 2wd/4wd) some have axuillary ports for adding things like a Power Take Off, some are gear driven, while others are chain driven, and lastly the case itself can be made from different kinds of metals.
The 1987-1996 Ford Bronco came with a few different variants of the BW1345 and 1356 transfer cases. But we are only going to talk about the BW1356. First off its one of the strongest chain driven transfer cases with one huge flaw; the back half of the case is made out of magnesium while the front half is made out of aluminum. The magnesium is a very brittle material and off roading means a great chance to crack it. Especially since the case hangs lower than the front differential. Another drawback to the transfer case is the underdrive (low range) gear ratio at a mild of 2.61:1. Another thing to consider is there arent any twin stick conversions offered at this time. And lastly there aren't any replacement low gear options available for it.
The 3rd thing I touched on was twin sticking (adding a second shift lever to the transfer case). There are only a very small amount of transfer cases that allow for thisconversions. The Dana 300, NP205, and some Toyota cases allow this mod. So what exactly is the benefits of adding the second snifter. Well the single lever gives you the option of Rear 2wd high range, 4wd High range, Neutral, and 4wd low range. When you twin stick you now have the ablity to select fwd high, fwd low, rwd high, rwd low, 4wd high and 4wd low. Each stick controls an axle, allowing the axle to be engaged in high, neutral or low range. There is a saftey mechanism built into the conversions that wont allow one axle to be in low range and the other in high range. to understand the full benifit of being able to control each axle independently research "front digs".
The last thing I mentioned was the doubler (also known as the crawl box) box (4th shift lever or stick if you will). Like I said earlier the BW1356 has a low range of 2.61:1 which is ok, it can be better when given 4:1 and even lower gears are options for certaia low range n transfer cases. But going with such steep gears comes a huge price to pay, your top speed in low range is greatly reduced. Adding a doubler using the same range box as the original transfer case (if this is an option, as in some cases there isnt a kit or adapter to do it) Doubles the low range when the range box is engahed. On the BW1356 this would give me a low range of 5.22:1 low range with the doubler engaged (2.6:1 x 2, or low range doubled). With the doubler disengage (high range) I would have the stock 2.61 low range available. Now all of these numbers are using stock BW1356 gear ratios, but I said im getting rid of the stock transfer case and using a NP208 trnasfercase mated up to an NP205 amking a 208/205 doubler. the Np 208 has a fsctory 2.76 low range, but a gear swap can achieve a 4.0:1 low range then backed behind the 205 with a 1.96:1 (may as well say 2.0) low range would give us a 8:1 low range with both transfer cases set to low range or 4:1 with the range box in low and the 205 set to high, or a 2.0 low range with the 208 range box set in high and the 205 in low range. Then combined that with the 5 speed transmission and now you have 15 forward speeds and 4 reverse speeds.
