US Gear vs Doug Nash & 4WD Commonality

jaluhn83

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1) Anyone know exactly what the difference are between the Doug Nash & US Gear made dual range boxes? I know they're very similar but curious if there are any engineering changes. Namely how well do parts interchange between the 2?

2) Has anyone seen a 4WD version of a DNE/USG box? I know they offered them, but I've never seen or heard of anyone who actually laid eyes on one. 2WD versions seem to be somewhat common, just never seen a 4WD. Unfortunately what I really need is a 4WD unit or at least the rear case half/output shaft for one.

Thanks,
~John
 

jaluhn83

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Interestingly, none of the US Gear parts/repair manuals I have show a 4WD tailhousing or output shaft, yet they clearly say that it's supposed to fit between the trans and t-case, which seems to me like it'd require a different rear casing.
 

GOOSE

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I would love to see one of these. An overdrive that married up between the trans and tcase would be the best design possible offering oyu useage in high and low range 4wd. My question would be how these units hold up in our application.......
 

The Warden

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2) Has anyone seen a 4WD version of a DNE/USG box? I know they offered them, but I've never seen or heard of anyone who actually laid eyes on one. 2WD versions seem to be somewhat common, just never seen a 4WD. Unfortunately what I really need is a 4WD unit or at least the rear case half/output shaft for one.

Here are some pictures of a 4x4 Doug Nash unit for you ;Sweet

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Also, there's a bit of discussion about the differences between the U.S. Gear and the Doug Nash units here: http://www.oilburners.net/forums/showthread.php?39326-It-followed-me-home-can-I-keep-it/page2

Hope this helps :angel:
 

junk

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I have a 4x4 US gear in my crewcab. If you check out my build thread that's linked in my sig, it shows it in there.
 

jaluhn83

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Nice! So they do exist..... Want to get rid of it?? :sly

I've got a US Gear underdrive and a line on a reasonably priced Doug Nash OD ($500) but neither are 4wd. I've been looking into doing so fab work to adapt the t-case to hang the US Gear box off the back, but I'm not sure how practical that's going to be. I think by the time I pay for the materials and the custom shaft adapter that would be needed it wouldn't be much cheaper than just getting a 4WD box.... if I could find one.

The other thing I'm looking at is that the 3.55/33/zf5 combo does a poor job of matching the power curve to road speed and I don't like the split between gears with the S47 - one option I was considering was to throw the 4.10 gears back in (which would also get me a limited slip rear, the 3.55 is open) and try to find an overdrive splitter. If I find a 4wd unit then installation becomes fairly straight forward - the t-case mount is going to take a fair a amount of finicky fab work and some machining I don't really have the gear to do.

Just tossing around ideas at the moment to see what makes the most sense.
 

towcat

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this adapter ring is also what needs to go with the USG Tim posted.
 

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jaluhn83

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Good point Calvin, I always forget about the clocking ring. They bolt pattern is the same as a t-case, but rotated for some reason.

Another thought I had today is that certain GM/Dodge trucks used a 32 spline output shaft.... so maybe I can find a 32 spline US Gear and cobble that onto the back of the t-case thereby eliminating the issue of the adapter shaft. Course it also means I'd have to find another gear box..... LOL
 

The Warden

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Nice! So they do exist..... Want to get rid of it?? :sly
Not on your life :angel: Like you, I've been wanting one of these for years...

I admit that, if someone came up to me with a Brownie box with an overdrive gear and the brackets ready to install in a Ford like what RLDSL did, I'd seriously consider a trade...but, that's only because I'm concerned about parts availability, particularly the shift motor (I'm also missing the electrical stuff, but towcat and I are hoping we can deal with that). I've heard that the shift motor's interchangeable with some motors out of split rear ends, but that's something I need to confirm...I know that the bearings, thrust washers, etc can be fabricated by the right guy ;Sweet but the company who bought U.S. Gear does not support these units and want nothing to do with them, so there's essentially no support out there. So, if you can find any cheap, I would jump on them...I have a 2WD under-drive unit that I bought for $100 for parts, for exactly this reason...
 

junk

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On the US gear for a manual truck the US gear wiring is like 6 wires. +12v, GND, 2 wires to the shift motor and 2 wires to the Switch. And then there is a "brain box" that I'm assuming is nothing more than a relay on a circuit board. Let me see if I have my documentation.
 

jaluhn83

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I don't think it'd be hard to clone the brain box - it's a a fairly simple circuit. I'll see if I can get a diagram together.

So it looks like I'm going to wind up with a T18/19 overdrive box too - found a guy with that and the TH400 box I need for my t-case mod. Anyone interested in the T-18/19 box? Supposedly good condition and completed removed from a hot shot truck.
 

justinray

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I don't think it'd be hard to clone the brain box - it's a a fairly simple circuit. I'll see if I can get a diagram together.

So it looks like I'm going to wind up with a T18/19 overdrive box too - found a guy with that and the TH400 box I need for my t-case mod. Anyone interested in the T-18/19 box? Supposedly good condition and completed removed from a hot shot truck.

Is it 4wd? Underdrive or overdrive? Im interested.
 

gonecrazyi

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There is a truck scrap yard here in Florida that use to sell the dne boxes. He still has tons of parts new in the boxes. He can be a little hard to deal with on prices but he does have hard to get parts I guess.
 

jaluhn83

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The T18/19 box is 2wd overdrive. It's got the case adapter and the short shaft and probably the electronics. Not sure exactly what I'll wind up with until I get it, but I should be able to put together a complete T18/19 box. It's a DNE too, not the US Gear but it's functionally the same.
 

Garbage_Mechan

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There is a way to have A GV between the trans and transfer case. Get one for a 88-97 F Superduty (often called a F450) Since the F SD used the 4wd trans and a "parking brake unit" that fit where the TC would go, it can be used on 4x4's in front of the TC. I have see a few around when I was searching for on for the 86.
 

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