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Old 08-27-2012, 03:45 AM   #7 (permalink)
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Quote:
Originally Posted by thomason2wheels View Post
Now that is really slick idea! Never does a day go by since signing on here that i dont read something that makes me look at things from a fresh viewpoint...god i love this place!
So hit the thanks so I get social points. If I do it you'll hear about it here.

Quote:
Originally Posted by shovel View Post
You could gut a transfer case, so that the chain and front output shaft aren't there...
I could but was hoping for even simpler - as far as I can tell the NP203 rangebox is divorced from the transfer case, that's why they can bolt it to another box, often an NP205 (which isn't divorced but I think is a better 4x4 box or something) although other combinations exist. Except i'm not a 4x4 expert - only viewing from afar. Although I think the box is iron, at least I dont have the weight of an unused transfer case on top of it, it's just the range box. Unless you know of another transfer case with a divorced range box...

Sample ORD Doubler 4:1 Dual Transfer Case, NP205-NP203 - Fullsize 4x4 Parts - if i'm not mistaken the NP203 rangebox is on the right going to your transmission, whereas the NP205 transfer case (with it's own built in rangebox) is on the left. What I want to do is that minus the rear transfer case really. The front should bolt to common transmissions including the TH400, TH700-R4, and various manual boxes, sometimes with adapters. What i'm not sure about is what the output shaft is and how hard it would be to have that go to a U-joint, since it normally expects to bolt to the transfer case piece behind it. Too much money spent on custom machining and it sorta kills the money saving aspect.

But as mentioned, would there be any other problems with oiling and anything else that anyone can figure out... or would the box overheat left in low range or some other problem? I was never sure whether the warnings "dont drive over 35mph" for instance were because most people are stupid and dont realize that thats top speed in 5th now for instance. I don't want to break down by the side of the road after thinking i've been all clever. Afterall the 4x4 crowd leave these in "hi" on the road and "lo" is for lower speed crawling. My shaft speeds shouldnt be MUCH different with the tall axles but who knows.

The NP203 is like a 1.96:1 range - which is just about right to go between ultra steep highway gears for a V8 and nice low 10k trailering gears in low range. I have no plan to shift "on the go", i'd go into "lo" range when entering bad hills and probably not exceed 55mph in overdrive. Heck depending on the speed it might never come out of Lo when towing heavy stuff at all. Under light loads and normal use it'd use the high range.

Another discussion - NP203/205 Doubler Articles and Links

Note another possibility is I saw once someone made an adapter to hook the rear of a TH400 into the front of another TH400, making the rear trans like a 3 speed auxillary transmission itself, but one you actually could shift on the go, typically converted to a manual valve body. It's possible i'd consider that as well but I don't like how the slush trannies suck power so considered straight gears more efficient.

Quote:
Originally Posted by oil pan 4 View Post
Toyota guys have been doing this since the 1980s.
Their transfe cases just happen to have the same bolt pattern on both ends and for some reason they are stackable.
They run 2 low ranges. Its the cheapest way to build a rock crawer that you can still drive on the highway just by changing tires.
Does an entire second transfer case bolt to the end (with some dead splitter hanging off the back) or is the box hacked up or is it a separate range box? What ratio does it use and what transmissions does it work with by chance?
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