I have an older 2wd F-150 (see my signature) which has been very good to me for nearly 300,000 miles. I have 3.73 gears and no overdrive. It never was a problem until I moved to Milford DE. Now everywhere I go is a highway ride away, and 2600 RPM at 60 MPH is a pain in the gas. I love my NP-435, but even when I pull an 8,000 lb trailer, I do not need low gear. I found a wrecked F-150 at the junkyard with a fresh M5OD. It's got a transfer case attached to it. I want to keep the case, remove the front drive chain and use it as a reduction gear to cure the M5OD's most annoying habit of requiring excess clutch slippage when backing up with a load. Also, If I need some extra gear for a heavy load, the transfer case low range and M5OD's 1st gear are still lower than the NP-435s low gear. My question is, can the transfer case shift between low and high range just by depressing the clutch pedal and pulling the lever, or do I need to stop first?

 

You have to stop before you can shift from low range into high range. I like your idea tho.

 

I have shifted my Dana 22 transfercase from high to low hundreds of times in my oldschool bronco. I've also done it with my 93 explorer many times. Going from low to high however requires more rev matching and the engine to come down in rpm while you lose ground speed. I have done the low to high before but not under load but cruising 20 mph.
Removing the chain and cutting the extra housing off the transfercase has been something I've wanted to try for a long time so I can add it all to a 76 f350 with a divorce mount np205 and have crazy dual low.
Giver a whirl. Let us know how it turns out. Someones gotta be the guineapig.

 

As said, if you plan on using the transfer case to get moving in low range, then shfit into high range as you're driving and go through the main gears again (like you do with some big trucks), that maynot work as you should be stopped to shift between ranges - I've done it on the fly with my old NP205, but your aluminum BW case may not take lightly to this. Backing up in low range is just fine tho, as a matter of fact this is the recommended way of backing up a heavy load with an E4OD trans due to its borderline-uselessly-high reverse gear ratio.

On a side note - is that Yamato in your avatar (StarBlazers)?

 

Yeah, I should have said that the dana22 is a gear-gear transfercase like the np205. They can hanle the abuse a lot better then the chains.
I still say give it a whirl and see if it works the way you want. A bw xfer is cheap, so if it bites the dust then no worries.

 

I think he was meaning to remove the chain and only use the xfer case as a gear reduction and remove the front driving portion of the case.

The Range gear is a gear to gear with a planetary gear set that does the reduction. I know the old NP205 could be done pretty quick by hitting the gas then letting of the gas to yank it back into high, probably not the best way though it worked. I am not saying you can absolutely pull that B/W from low to high, but you may be able to do it with practice. Else brush/build up on your double clutching skill set.

 

Yes it is! I grew up with Star Blazers. I am looking forward to a subtitled or re-dubbed version of the new movie that came out in Japan on Dec. 12, 2009. I don't know if you saw the clips on You Tube, but it looks crazy awesome! That is where my user name comes from... I named my truck The Argo back in '96 when I got her.

 

My plan is to use the transfer case to give me a low reverse for backing up with a trailer. As stated, I never need the low gear in my NP-435 as it is, and the M5OD's first gear is deeper than the NP-435's second gear. I want an overdrive for my highway drives. The reason I want to remove the chain is to prevent the chain from wearing though the case as I know sometimes happens.

 

Yes I've seen the clips, looks pretty darn good indeed. But I'm more of a SEED fan, if you couldn't tell by the avatar and sig. Oh yah, I named my truck the Archangel, altho based on color Dominion would be more suitable, but I hate that ship.

By the way, I don't think you need to remove the chain, if there's no load on it (cause there ain't no front driveshaft for it to power) it shouldn't do any damage to the case as it would be just idling in there.

 

I have to admit that besides Star Blazers/Yamato, I am not a big Anime follower. I enjoy it when I have the opportunity to watch it, as my nieces are really into it, however, I am a one trick pony I am afraid. As for the chain, you have a point, since I wouldn't be in 4Lo often, and I wouldn't be in 4Hi at all.

 

Eh, I don't keep a tarck of everything anime either, just those shows that sport spaceships and/or gun-totting chicks, haha!

On the chain thing - you are planning on just removing the chain from inside it, but leaving everything else in place, correct? I dunno if these transfer cases have a built-in oil pump for lubricating the gears in the range box, and if that somehow is dependent on the chain being there, but food for thought maybe?

 

How hard is it to convert an NP-435 to a 4WD output shaft? I really love this box, and I think I have a better solution. Instead of the M5OD, I'll just grab the BW transfer case, and install 2.73 gears in the rear. That way, I can keep the NP-435, and have an ultra low reverse for when I am backing up, and an ultra low 1st gear for pulling a parade float (I am a teacher, and use my truck for the homecoming parade), a 49.2:1 1st gear ratio and a 59.1:1 reverse ratio in low range, and an 1,800 rpm cruise rpm at 60 MPH. I think this is my best solution.

 

Not sure on that, never took one apart. But you can always run a divorced NP205 transfer case behind your 2wd trans, you'll need to have the driveshaft cut and made into two shafts tho...

 

I think the 5spd would be nice for the hyghway that's all. As far as lubing the xfer without the chain, when not in 4wd the chain don't turn anyway so the rest of the xfer must not need oil to be slung of the chain to stay lubed. If ground clearance is not an issue hen leave the whole xfer in there and when you need low for backing up use it. Otherwise use low for your parades and such. The not so low gear in the 5spd I don't think will hurt much.

 

I originally had 3.08 gears with the NP-435 and I had killer mileage under 65 MPH (I could pull an average 21.3 MPG with a steady foot and a close eye on the speedometer) and it pulled the 8K trailer no problem (I still rarely needed low gear). The problem is that the differential gave up at 230,000 and I did not have facilities to repair it, so I just had to swap the axle with a 3.73 unit I got at the junkyard. The only thing I didn't like was that the 3.08 gears still had me going too fast in reverse when backing a trailer in tight quarters, so I had to ride the clutch. I admit that this is one nice thing (the only nice thing) I have to say about the 3.73 gears; backing trailers in tight spots is easier on the clutch. They dropped my overall mileage to 13.2 MPG, with a highway average of 15.8, and no capability of going faster than 65 without screaming the engine. I rarely exceed the posted limits because fuel is expensive, but when my grandfather was dying a year ago and I got a call from my father saying get here fast, I drove from Woodside DE to Springfield PA at 85 MPH, and the tach hovering on 3,800. That was for over 100 miles. I didn't like that experience. FYI My mileage for that tankload was only 9.4 MPG. Given that this was an unusual occurrence, this incident is not part of my MPG average with this axle, or it would be even worse. The M5OD would give me an effective 2.93:1 ratio when it's overdrive is multiplied be the 3.73 ratio. 2.73 gears, on the other hand, along with the NP-435, would give me an even better overall cruising ratio, but then I have that "fast" reverse problem even moreso than when I has 3.08 gears. Thus the transfer case for gear reduction. Also, when trying to pull a float at 1.5 MPH, I'd still have to slip the clutch with the NP-435's low gear with 2.73/3.08 gears, but I could easily do it with the NP-435's lo gear and the 2.62 ratio of the transfer case lo range. 2.73x2.62= 7.15:1 final drive. With the NP-435 6.88:1 lo gear, I end up with an ultra low 49.2:1 compound lo ratio, perfect for creeping in a parade without slipping the clutch... or pulling a house off it's foundation at idle. With 2.73 gears. I think I have found my solution... I love math.