In the realm of theory...what would stop someone from installing a second NP 205 behind the original, but turning it 180 degrees. This would put the output yokes on both 205's facing each other. The idea being that you could place the 2nd 205 in low gear. But, since it is backwards it would in fact rougly double the output speed, rather than lower it. Effectively dropping your engine RPM and increasing speed (not that I really want to go too fast in my 77 F250).

Why??? Because

Thanks!

 

i believe people do this to get a overdrive with 2 transmissions.. not sure about the transfer case.. but i doulbt a low would handle much rpms for long. i could be wrong though..

Ray

 

Thank you greythorn3. These things pop into my head while I am driving down the road thinking why do I have 410's in the rear?

 

Take an old 3 speed tranny put it backwards ????

 

Leaving the whole mechanical difficulties tying the two together alone, (outputs for 4wd, and making a shifter that would have to make a "u" turn to shift the rear box, and the weaknesses associated with trying to output from an input shaft, without the advantage of gear reduction) and just looking at the theory, you would basically be cutting output ratios by too much, and this is for the rear axle only. Failure to be able to shift the rear box out of low range would mean that 4wd would no longer operate, since the front and rear axles would be turning at different rates.
This theory would be like running a 2:1 rear axle ratio.
The engine does not make enough torque to accomplish this, nor could it go fast enough to bring the engine up to operating rpm's.
Speed is directly related to horsepower and torque.
The same engine will run at the same miles per hour with different gear ratios, the only difference would be the engine rpm.
There comes a point when the gear ratio is so high that it becomes inefficient and the engine struggles to accelerate.
If you are looking to lower rpms, going to a 1:2 output would be way too much, and the engine would have to drop down to the low gear to try to compensate for the final drive ratio loss, making the modification not very practical.
Adding an overdrive with a reasonable output, (.7X:1) or dropping to a numericaly lower axle ratio would be a little more practical.
Interesting theory though.

 

check out the ORD np205-203 double kit.
http://www.offroaddesign.com/transfercaseparts.htm

mostly just rockcrawling people do it.

 

im running one of these kits too.. with a 203 gearbox and a 205 transfercase.. works great.. super low.. can snap stuff in a blip of the throttle..


ray