Divorced t case for a rear engined wagon

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Heath
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Divorced t case for a rear engined wagon

Post by Heath »

So what Transfer cases are able to be clocked so the outputs are on the correct side if they are spun 180 so the input is from the rear of the wagon.

I have a plan to fit a fwd car engine (complete with auto gearbox) in the rear of a project but need to figure out which tranfer case to use (is divorced from gear box) and can be utilised. Intention is to be able to disconect the rear wheels (which will be connected to the normal front wheel drive output) and pull the front round using just the front wheels.

The other option is to use axles which have their input from the passenger side.

Of course I could run a rotated 410 transfer case and a hilux front axle in the rear (rear wheel steer - cher!!!) and a simillar ratio front axle with the input on the pass side.

At this stage I am just sorting ideas before taking the plunge and start making my frankenstein monster. Its just a fun wagon to thrash and wreck (hence the cheap engine type).

Thats the plan anyway... :mrgreen:
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mudslut
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Re: Divorced t case for a rear engined wagon

Post by mudslut »

Sounds mean cuz :D
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Heath
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Re: Divorced t case for a rear engined wagon

Post by Heath »

Yeah the plan is something light in the front (might even long travel IFS it - but thats another line of thought), have a light screamer of an engine (maybe a rotary) and of course it will be a trailer queen.

Jumps anyone... :wink:
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LOLYF
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Re: Divorced t case for a rear engined wagon

Post by LOLYF »

If your going to use a FWD engine just leave the gearbox on it,weld the diff and run the half shafts to your front and rear diffs.
Some honda engines run in reverse rotation so when you turn the engine around the shafts run in the correct rotation to your diffs.
the other option is to run the diffs upside down.
Don't know how you'd go about the front dig thing :(

Another advantage is you get about 4-1 transfer case ratio. (but no high range at all)

If your intent on using a transfercase then a datsun 720 will do what you want, and no you can't have the one sitting on my garage floor ( I have plans for it :wink: )
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Rotazuk
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Re: Divorced t case for a rear engined wagon

Post by Rotazuk »

A honda engine is only going to help if you mate it to another gearbox , otherwise the shafts turn just the same way as any other matched engine/ gearbox combo .
A rotary engine is not light and very difficult to mate to a fwd gearbox .

Running a fwd engine in the rear means your gearbox output is turning the wrong way , as said one ( and probably the easiest ) way is to run the diff heads upside down . Or one step further just get a set of prado diffs (head offset to the right ) flip them upside down so the head is to the left to align with the output of the gearbox and or t/case and they will run the correct way .

Only nissans , late model hilux and some jeeps had left hand output in the t/case I think . It looks like the 720 case is a right hand output . I guess you could divorce a terano case but is it really worth the weight just to get front disconnect as you will not be able to run the low ratio in the t/case . May as well just get a drive line disconnect or something .

Hope you get some ideas from people to keep on thinking .

Cheers
Chris
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turoa
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Re: Divorced t case for a rear engined wagon

Post by turoa »

Rotazuk wrote:A honda engine is only going to help if you mate it to another gearbox , otherwise the shafts turn just the same way as any other matched engine/ gearbox combo .


Nope, the motor/box is mounted the opposite way round to normal to compensate for the shafts running backwards :wink:

But yea not really usre how you're gonna do a front dig if the rear wheels are permanently connected and having the front discconnect?
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Heath
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Re: Divorced t case for a rear engined wagon

Post by Heath »

The idea is to run an east west engine and gearbox combo (weld the diff) with the forward facing shaft linked to a transfer case rotated with the input facing rearward.

This would place the rear out put forwards and the forwads output facing the rear. This means if I was to select 2wd then only output would be to the front (hence front wheel drive only). I intended to run the auto gearbox into the tcase and then to the diffs giving me a very low ratio. But I would combat this with low ratio diffs (4.1 or whatever) and run larger tyres.

This wagon is just for fun and giggles (more to play with ideas) than for rear 4wding. My ideas may be a waste of time but I intend to learn as I go. Hell I might create a monster that works or a pile of junk that will just be a assembly of spare parts.

Now the idea of running diffs upside down is appealing A lux front in the rear and a lux front one flipped would work I guess. Just have to sort out the seals, diffs, etc will work upside down. Pain in the arse to sort the steering and pinion angles though, might be easier to cut the diff tubes and shift the diff head across.
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turoa
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Re: Divorced t case for a rear engined wagon

Post by turoa »

Aha I see so you're only using one of the outputs from the transaxle? Running an extra tranfercase seems to be an overcomplication and extra weight. Why not just run a driveline disconnect off one of the outputs from the transaxle and run the output that faces the rear of the vehcile to the rear diff and the output that faces the front of the vehicle to the front diff?

BTW, front digs dont work that well on mud. Fiddles work way better.
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getsum
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Re: Divorced t case for a rear engined wagon

Post by getsum »

rotarys can be easily bolted up to a fwd familia gearbox..
has been done heaps...


this project sounds interesting... 8)
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Rotazuk
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Re: Divorced t case for a rear engined wagon

Post by Rotazuk »

turoa wrote:Nope, the motor/box is mounted the opposite way round to normal to compensate for the shafts running backwards :wink:



You are right , I am still thinking of having the engine in the front , doh .

The question I have is can a honda auto be made to run backwards :)

getsum wrote: rotarys can be easily bolted up to a fwd familia gearbox..
has been done heaps...


Really , heaps eh . Show me a pic of one . From an extensive web search I have found two that run fwd box . A 12a into a Manta and a honda civic . I have been told there was a famila here in nz with one but not sure if it was running a famila gearbox . Wonder how long it would last anyway . They do not bolt up to the famila gearbox they would have had an adapter in there somewhere . The issue is getting the drive shaft clear of the exhaust ports . Still if heath ran a t/case on the back of the auto as he talks about he would resolve this problem .

Image

The honda would have been a manual so they would have run the gearbox in reverse rotation but at least the shaft would have gone down the other side of the engine .

Anyway back on to Heaths issues , sounds like a plan is forming . I agree with Turoa and don't think the extra t/case is worth it . Also check your ratios as you don't want to run anything bigger than a 4.3 diff with a fwd gearbox anyway , so adding a t/case will give you great rock crawler ratios .

Chris
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Pedro
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Re: Divorced t case for a rear engined wagon

Post by Pedro »

Rotazuk wrote:
turoa wrote:Nope, the motor/box is mounted the opposite way round to normal to compensate for the shafts running backwards :wink:



You are right , I am still thinking of having the engine in the front , doh .

The question I have is can a honda auto be made to run backwards :)

getsum wrote: rotarys can be easily bolted up to a fwd familia gearbox..
has been done heaps...


Really , heaps eh . Show me a pic of one . From an extensive web search I have found two that run fwd box . A 12a into a Manta and a honda civic . I have been told there was a famila here in nz with one but not sure if it was running a famila gearbox . Wonder how long it would last anyway . They do not bolt up to the famila gearbox they would have had an adapter in there somewhere . The issue is getting the drive shaft clear of the exhaust ports .

Image


add a 80 -100 mm spacer between motor and g/box, should give enough room for the driveshaft, using a smaller universal and putting the sliding splines to bottom of the shaft,

neat power plant setup,

with a 12k rev on a a rotary with a windom box it would sure get along well

Pedro
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getsum
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Re: Divorced t case for a rear engined wagon

Post by getsum »

never said it bolted staright up..
ive seen atleast 8 of them in my day being a former rotary nut myself..

rotarys dont have the torque anyway and a familia gearbox will lunch itself rather quick..

do a search for lawton rotarys, or rotahavik...you will soon find something...definately not the cheapest option...
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Heath
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Re: Divorced t case for a rear engined wagon

Post by Heath »

Still planning stage at the mo so details are being sorted as I go (dream them up), Final ratios etc will be dependant on the donor engine/box (mitsi Magna/astron maybe) and the tcase is there for the low stuff (big tyres (35-37's) are the aim) and to increase the torque. Might be totally impractical and too low geared but then I'll figure it out when it happens.

The good thing is I will be using the gear sets (diffs/tcase)everyone throws away as they arent low enough (and of course that means they will be stronger - in general).

The idea of cutting a front up to move things around is appealing just from an engineering project point of view and with bracing should be as strong if not stronger than std. Saw a tube rear zuk in a mag a few days ago - Hmmm...

I wonder if I could take the tcase and cut the input shaft housing, spin it and re attach it so the input is from the rear, or shift the input shaft out through the rear of the housing and blank the front off?
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Heath
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Re: Divorced t case for a rear engined wagon

Post by Heath »

The idea of a rotary engine is just so I can gain back some speed through their huge rev range as this will be low geared (hi ratio will resemble low in a normal wagon) and they have a dry sump (IF i REMEMBER CORRECTLY) so no angle issues.
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getsum
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Re: Divorced t case for a rear engined wagon

Post by getsum »

not a proper dry sump, they just have the bonus of not having an open crank into the sump..the oil pick up can still easily be left high and dry if the oil level gets low and angles increase..

if you have low gearing then a 13b would scream its head off nicely..
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