Join Date: Sep 1999
Location: Southeast Iowa
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Green Machine\'s great NP205 pics!
[img]/wwwthreads_images/icons/smile.gif[/img] Green Machine has vastly improved on the Petersen's article regarding the mods to the NP 205 transfer case. The photos and explanations are waaaaayyy better. [img]/wwwthreads_images/icons/smile.gif[/img] What most folks don't realize about the NP205 is that the two rails are actually not "range" and "mode", but are in reality: "rear" and "front". The front and rear axles get their power off the opposite sides of the countershaft gears, and in fact, all of the gears are meshed all the time. Because the center countershaft is supported from both sides, it is just about impossible for it to push away and slip a tooth. That gearbox is a lot like the twin-countershaft Fuller million-mile truck transmission, except the NP205 has one countershaft and two output shafts. The power comes in to the NP205 on one gear which spins the countershaft. That gear is 1:1 and it gives the front axle direct drive through a matching gear on the front output shaft. Rear drive in direct is done with the sliding clutch on the rear output shaft so the countershaft only has front axle load on it in direct drive. In UNDER drive, both clutches are clicked to the rear and both output shafts feed from the smaller gear on the countershaft which then gives 1.96:1 underdrive. It's absurdly simple and VERY tough, yet easy to shift up or down because you either double rhe RPM or cut it in half to change from under to direct or vice versa.[img]/wwwthreads_images/icons/smile.gif[/img] That photo spread by Greenmachine is a keeper![img]/wwwthreads_images/icons/tongue.gif[/img]
A moonguy-operated Jeep Skunkworks in the "Heartland".