That sound like fun, I would love too see a truck pull against it self.

 

Depends on which direction you put the diff in, for example you have a 79" f-250
with a low pinion rear diff and you take another low pinion rear diff and mount it in the front of the truck with the pinion on the low side both diffs will drive in the same direction, but say you turn it over so the pinon is on top (therfore on the other side (left to right) of the ring gear) it will now driv in the opposite direction making the truck pull or push against itself,

wow, I just divided a subject inside itself, that might be a little hard to fallow,

 

I don't know where i heard this but i think that Advanced adapters make a case that lets you do this, if i remember right its just 2 gears mounted one one top of the other then its mounted between the tranny and t-case.

I think it was that monster garage episode mentioned above that i heard about it.

 

Yeah, I just tested my theory. If you are facing forward everything turns in a counter clockwise direction meaning if you spin it around the t-case outputs are spinning clockwise. I suppose you could have custom axles built if nothing else, using a rear center up front and a front center in the back. But I don't know that these gears can run at high speed or torque when they're being run in reverse. So basically you'd need to change this either at the tranny or at the T-case. I may have to call Advance and see if they have any ideas.

 

V-drive boats use a box that has the input and output on the same side. The motor sits faceing the rear of the boat with the DS going forward to the v-drive. then another DS goes back to the prop. You could do the same with a truck. The propshaft would go to the T-case instead of a prop.Unlinited Drag boats have beefy units that may or may not handle this dind of abuse.

 

Couldnt you just use reverse cut gears meant for the high pinion dana 44 or 60 to solve the reverse rotaiton? or do they not fit in a standard housing? Oh and the wheelie cars i looked at the owner said the tcase was from an old duece and a half the old gmc ones after a little research I found out the front output on those is opposite the rear, thats how he still went forward.

 

Wacky stuff . . . I'm half lit and the longer I look at it the more confused I get. I played around with my spare 205 and D70 and just made myself dizzy trying to figure out what's going on. I'll check with a few companies and let you guys know if I get an answer. I don't plan to do this too soon but it's in the works for a "down the road" project. Just had it on the brain today and wanted to get some oppinions.

 

The reason I said to use the G.M./dodge front diff is because they run on the coast side in a G.M>/dodge truck, so turning it over will get you back on the drive side of the gear not to mention it will be a high pinion because it is now flipped over, now on the rear you might be able to install a set of reverse rotation (ford high pinion) D60 gearset after you flip it over and be on the drive side there aswell, also you'll have a high pinion rear diff, don't forget to modify your oiling passages if you do this,

Ivan in your other thread you mentioned no one will be able to see the keg in the bed of your truck, after you do this conversion they really won't see it because you'll be hauling it around under the hood, (you'll have to encorporate a tap handle in your fancy new dash)

 

Well that was my concern . . . if you flip an axle over how do you keep the lubricant going everywhere it's supposed to?

Of course using a married NP205 like I was thinking of would actually put your new rear output on the passenger's side and the front output in the middle!

 

Not to mention when you put it in 2WD it will be pulling with the front tires only,

I talked to the guy at SCS gear and one of his puller drop boxes runs about $1,195, pretty nice unit, all gear and only weighs 89lbs, it is a devorce mount unit and can be mounted in any configuration,(canted towards either side) the down side is the you cannot get 1:1, the highest ratio you can get is something like 1.6:1, he also said theat he sells intermediate gear sets to change to what ever ratio you would like within its range, I put a couple pics in my gallery under misc parts of the two scs boxes that are avialable, one is the puller bux & the other is the monster truck box,

As far as oiling goes I'm sure a little port work in the diffs would fix you right up, I'm going to have to look into this myself since I'm running a D70 backwards,

 

as far as oiling goes why not use something like they do in nascar with the 9in which is a pump driven off a pulley on the ujoint yolk.
And you could always go with a custom ground cam that is set for reverse rotation of the engine and run the engine backwards (some marine engines ran this way)

 

I have a very boring 10 hour a night job. So during this time I have conjured up many different vehicles in my head and worked out the mechanical details as to if it was possible-(amphibious,6 wheel drive,tracks,etc.) Rear engine is one of the things I have mulled over, and although I have came up with a couple of different combinations, here is what I feel would be the best and why. Set your engine, tranny and T-case in the back with engine facing forward, run a driveshaft from the front output to a divorced 205 that is in roughly the "normal" location for the T-case, but turn it so the input is facing the rear of the truck. (output of rear case hooks to input of front case) What used to be the rear yoke is now the front and vice-versa. I imagine this type of setup would require a generous amount of lift to make room for the driveshaft that connects the cases. The main disadvantages are that now there are more parts to maintain and potentially break, and putting front case in 2wd would get you front wheel drive unless you did a twin stick on it. The advantages are that you now have dual low ranges also

 

The perfet example of a rear engine 4wd is a monster truck, everyone I've seen & can think of that is rear engine mounted has the engine turned around,
and after looking at the picture of the monster truck drop box it looks like they do infact reverse the rotatoin in the box,
wyldstallyn has an interesting idea, but that front wheel drive thing is kind of a hangup, incase you can't tell I'm pretty interested in this topic, If I ever get caught up with my projects I think I'll tackle something like a rear engine truck, (already have a set of 2.5 ton diffs and a set of 55" firestones) I think may have just found a home for them,

 

Thank you Jesse! The second I read the first post this was my answer, I'm just surprised that nobody else chimed in.
As for the engine-running-backwards, I think that might mess with the transmission. But if it did work, heck, you'd have three reverse gears!
I'm almost 100% sure all you'd need is reverse cut gears. You figure, the standard cut gears are designed to go in direction <a> when spinning clockwise (for example). To remain going in direction <a> when spinning counter-clockwise, all you'll need is reverse cut gears, and last I checked, the pre-78 (closed knuckle) dana-44 fronts were pinion-under pumpkins, and the open knuckle 44's were pinion-over or pinion-even, so I THINK they used a different cut, so all you'd have to do is get the reverse rotation gears. I'm pretty sure that getting reverse rotation gears would make this project do-able.
Now, Ivan, if you wanna get REAL bling, then you could make a planetary gearset that bolts to each hub with only two gears, so that when 1 gear spun 1 way, the other would spin opposite, then you can make whatever gear option's you want, kinda like those terra-whatever drop-knuckle 60's you see in 4WOR for $10k a pop.
I sent Currie Enterprises an email asking what it would cost to get a hi-pinion 9" rear-end, and they specified the need for reverse-cut gears. Get a set of those gears and reverse-cut 44's and there you got a half-ton rear-mount show truck. I wouldn't imagine that getting reverse-cut dana 60 gears would be too terribly difficult. Don't forget the chrome plated mufflers and spring hangers!

 

As for the front wheel drive problem it can be fixed if you run a divorced np200 the t case could stay in its normal position with the front output facing forward the input shaft runs straight through with yokes on both sides, so just run the input into the back side of the case. the only problem is the offset of the outputs they are also inline so either both diffs would have to be offset to the passenger side, or if you were going high enough you could run it straight down like a drop box but then you would have to have front and rear diffs centered.But I would like to find a way to fix the rotation problem before the axles making it possible to run rockwells.