(Not quite Bullnose but...) Rare ‘79 4x4 V drive van

[Ford F834]

Not quite sure what to think of this ad since the pictures seem to be of different ages, and/or different vehicles. It’s an odd V drive 4x4 with three drive shafts and two front differentials. Just thought it was unusual enough to be worth sharing...

https://phoenix.craigslist.org/wvl/cto/d/quartzsite-very-rare-4x-vemco-drive-3/6804664945.html

[Gary Lewis]

Wow!  V-drive?  How does that work?  Are there two transfer cases?  What powers the right-side driveshaft?  There must be a differential in there as well?

Those front diff's look serious.  Far heavier than the D44's I'm used to seeing.  What are they?

That's an interesting truck!

[Ford F834]

I’ve seen this V drive thing before, and I believe it has one transfer case with two front outputs on either side of the transmission input, but it’s been a while since I’ve run across it. I have no idea what they were like to use, but it looks horribly expensive and complicated to mske it that way.

[Ford F834]

Found that link with the gory details...

https://www.blueovaltrucks.com/tech-articles/axles/the_vemco_v-drive_system/

[Gary Lewis]

Here's the scoop on VEMCO.

A low vehicle profile is obtained in a front wheel drive system by providing a V-drive axle center section at the rear of a transmission with a pair of forwardly extending V-shaped output or drive shafts. The output shafts are adapted to drive a pair of angled forwardly extending propeller shafts disposed on opposite sides of the center section so that drive can be transmitted to separate gear units located at each front wheel for individually driving the same. Equalization of power between the front wheels is accomplished by means of a conventional bevel gear differential located in one of the output shafts with drive to the differential being through a pinion gear keyed to an adapter sleeve serving as the axle center section input shaft. The front wheel drive system is easily converted into a four-wheel drive system by merely removing the adapter sleeve and inserting in its place a second differential of the worm gear type. By this arrangement input drive is then transmitted to the second differential with the drive divided by the worm gearing in such a manner as to have a portion directed to the first differential located on the center section output shaft and portion directed to a rearwardly extending propeller shaft for driving the rear wheels of the vehicle while still maintaining the desired low vehicle profile.

[Gary Lewis]

You beat me.  But, it took more time to copy & paste.  

[grumpin]

That's interesting! Never seen one before.

[Steve83]

Each front drive is essentially a D44IFS chunk with a spool (no differential) and only 1 output.

Contrary to their marketing, the vehicle profile is NOT "low".  Neither is the unsprung weight, resulting in a rough ride & poor handling.

But it's certainly interesting & creative!  And it's almost worth saving, just as an oddity.




This rare van is actually driving around here:

[Rembrant]

Steve83 wrote

Contrary to their marketing, the vehicle profile is NOT "low".  Neither is the unsprung weight, resulting in a rough ride & poor handling.

But it's certainly interesting & creative!  And it's almost worth saving, just as an oddity.

It certainly IS interesting AND creative! But it is wildly unnecessary...at least in the sense of the advertised (or perceived) benefits of the V-Drive system.

I see the 4x4 Ford vans for sale in Canada on a fairly regular basis, but never one of these animals. The E150 and E250 4x4 vans were popular here up north/west for hauling workers around from tree planting to oil fields, to mining.

Thanks for sharing Jonathan. That thing is as cool as the other side of the pillow.

[Gary Lewis]

Yes, I've see 4x4 Ford vans for decades, so that complexity isn't necessary.  And the un-sprung weight would go through the roof.

As for saving, I wonder how hard the parts would be to find?

[Rembrant]

Looking through the links, I have some questions...lol.

That V-Drive case looks to be a very simple drive. No big deal there, but, these things would be full time, full speed 4x4, right?

And, based on Steve's comments above about each front diff each having a spool, wouldn't this thing bind up like crazy when turning?

PS: I have no experience with 4x4 locked front diffs, so the above may be a stupid question.  

[Steve83]

Rembrant wrote

...these things would be full time, full speed 4x4, right?

I don't think so - I think it's a part-time t-case, and I assume 2-speed.

Rembrant wrote

...each front diff each having a spool...

No, that's not what I said.  The drives are just built that way.  But the diff between the front drivelines is in the t-case, so it still steers like normal.  That's described (poorly) in the link that Gary quoted.

[Gary Lewis]

Yeah, "poorly" is being kind.  I think a lawyer wrote what he thought he understood an engineer to say.  (I have to be careful as my son, who is a member on here, is a lawyer and I've been accused of being an engineer.)

Anyway, my understanding of it is like Steve's - it is a differential within a transfer case, so apportions power to the front wheels exactly the same as an F-Series front diff does.

[Steve83]

Gary Lewis wrote

I think a lawyer wrote what he thought he understood an engineer to say.

It's actually written like a patent.  One of my good friends from high school is an IP attorney, and when he lived in DC, I did a little research on a patent, which involves reading a BUNCH of them.  So I think that description was copied from their patent.