Rear-engined "Special"

[landybehr]

Hi there,

I have an old Discovery chassis that I could give to a friend. He´s keeping a small fleet of Buggies - the VW-beetle based "things" with a plastic body. Somewhere he´s seen a Buggy that was put onto a Land Rover chassis. Well, gives him 4WD, some unusual high ride and something special. And I would get rid of the chassis and axles to gain some space.

Now wheelbase is only a little more than needed, no problem to cut some length out. Width will be ok.

Problem is that Buggy-men want to have the engine at the rear. And this spells for trouble with the rear A-Frame.

Has someone any more concrete info about some project of this kind already made ? Or which gearbox/engine was used with a rear-engined rig ? I´ve seen a pic of a rear-engined LR but that was based on a SI-chassis with leaf springs, we want to keep the coils ?

Pics would be great. I´ll keep using google but hope some of you can help

Thanks!

Hendrik

[Hybrid_From_Hell]

Like this ?

Nige

[missingsid]

Nice but why backwards tyres

[Hybrid_From_Hell]

Erm

American ?

Seriously I recall reading something around this re rock crawling and grip, not sure why but there is probably a reason

Nige

[LR90]

Check out Saley's truck, rear engined and very special

[Henry Webster]

Take a trip to any off road racing event. AWDC, NORC, BORC or Hillrally. Lots of rear engined specials in the racing world.

The trick in many cases is to ditch the A-Frame and replace with a panhard rod and radius arm system like the front.

H

[bill van snorkle]

It has been done many times before with conventional gearbox/transfercase assemblies, and with the relatively light weight of a buggy, the fact that the diffs must be flipped and therefore the rear diff is only 70% as strong than when running on the correct side of the crownwheel teeth , may not present too many problems.A reverse cut crownwheel and pinion in the rear diff should sort that out.

Bill.

[discojmz]

Erm

American ?

Seriously I recall reading something around this re rock crawling and grip, not sure why but there is probably a reason

Nige

very true, the tread on that tyre has essentially arrow profiled cleats/lugs in it similar to on a tractor. most people dont know that a tractor grips best in reverse, the soil or whatever is forced into the cupped apex of the tread which as you can imagine, grips a whole lot better. the reason for not running the tyres backwards is that they become too noisy and difficult to turn on the road and the treads wont self clear any more. the displacement of the soil even when gripped forwards is more than sufficient for the tractor's forward motion but the first rule of tractor driving is when ascending a ludicrously steep incline, do so in reverse

[Orgasmic Farmer]

Tractor tyres grip better in reverse? Hey? You want to come here and try reversing up a bank to knock fence posts in in winter. Almost zero grip. Same slope can be comfortably driven forwards. Perhaps you speak from experience but certainly with the soils we have round here the absolute 100% opposite to what you have said is true. The reason for going backwards up a slope is because you are unlike to get as far (and hence into real trouble) than going forwards, plus you still have all the grip available to drive safely back down the hill under control. Usually though you will reverse up steep hills because you have an implement on the rear which will cause the front wheels to lift and it will be impossible to turn round on the steep bank to come back down. Quite often things like telehandlers will have one set of tyres reversed but they are designed to spend as much time going backwards as forwards.

[landybehr]

Errmm, yes, something like in the pic above. Will look less impressive, I hope

Ok, Panhard Rod will be easy enough to do.

But what can be done with the diffs being on the wronge side with a rear engine

(I don´t think it´s a good idea to flip the axles)

+

AFAIS with stock LR drivetrain and stock axles the setup in question will get 4-5 reverse and 1 forward gear.

That´s why I hope for a transmission from a different car that turns the shafts other way round in it´s origin setup and serves diffs that are l/h (like in the P38).

Pirate4x4.com has a thread about that, but I think they used big truck axles from a 6x6 which were modified in a way completely unsuitable for Rover axles.

[Orgasmic Farmer]

http://www.awdc.co.uk/data/awdc.nsf/cbe586...33;OpenDocument

something like this

[Henry Webster]

Indeed Milner and Rakeway do reverse rotation transfer boxes in the UK, which is the easiest and best way. Otherwise you are into flipping and cutting and shutting axles!

H

[saley]

Indeed Milner and Rakeway do reverse rotation transfer boxes in the UK, which is the easiest and best way. Otherwise you are into flipping and cutting and shutting axles!

H

You still have to cut and stut the axles because the diffs are on the wrong side unless you use p38 axles which are opposite to a landrover

[nicksmelly]

On the wrong side for what?

[bill van snorkle]

if I wanted to build a rear engined LandRover based vehicle on the cheap I would leave the transfercase in more or less its normal location and feed the drive from the gearbox into the back of the t/case via the PTO aperture with an adaptor plate.This may require a male/female mainshaft extension, usually called a spud shaft, but it is considerably cheaper than a reverse rotation transfercase, or fitting carp unit bearing P38 axles.Would still have to flip the diff centres inside the housings, but that isn't a daunting task. There is nothing about the design and construction of the LT230 transfercase thatwould make it less efficient or durable when driven backwards.

Bill.

[landybehr]

Bill ... what an exceptionally GOOD idea !!! The LT230 will stay then. I think he could use a mechanical PTO-cover (those with the cardan-flange) and connect that to one standard 2WD automatic gearbox with any engine via a short custom propshaft.

Turning the diffs by 180degrees in their housing is easy, just need to make a new cutout for the crownwheel. Just in case someone knows - if we did so, could some of the bolts stay to align the diff in the mentioned rotation in relation to the half shafts ?

if I wanted to build a rear engined LandRover based vehicle on the cheap I would leave the transfercase in more or less its normal location and feed the drive from the gearbox into the back of the t/case via the PTO aperture with an adaptor plate.This may require a male/female mainshaft extension, usually called a spud shaft, but it is considerably cheaper than a reverse rotation transfercase, or fitting carp unit bearing P38 axles.Would still have to flip the diff centres inside the housings, but that isn't a daunting task. There is nothing about the design and construction of the LT230 transfercase thatwould make it less efficient or durable when driven backwards.

Bill.

[bill van snorkle]

I flipped my diffs a few years ago to drive the portals, and IIRC not a single bolt/stud hole could be re used. I mig welded up all the holes by holding a piece of brass behind and puddle welding. I also had to weld a couple of pieces in where the old crownwheel clearance cutouts were because that area iswhere a couple of studs go.

The thing that worries me about driving in the back of the transfercase using a PTO is that the PTO dog teeth on LT230's don't appear to be very substantial because they have been generated with a deep undercut behind them. Better to modify the PTO shaft to engage with the 10 spline centre.

bill.

[saley]

On the wrong side for what?

the wrong side of the car.landrover diffs, props, transfercase are on the drivers side turn the engine and you have to put the diffs on the passenger side so everything runs in line, you also have to modify the sump depending on what engine you use as the rear diff is closer to the middle of the car than the front and use a shaft prop rather than a tube to give more clearance also

[Mark90]

You still have to cut and stut the axles because the diffs are on the wrong side unless you use p38 axles which are opposite to a landrover

With Milner/Rakeway reverse rotation transfer box you don't have to mess with the diffs, no flipping them or moving them to the other side is required.

[saley]

With Milner/Rakeway reverse rotation transfer box you don't have to mess with the diffs, no flipping them or moving them to the other side is required.

Do Milner/Rakeway make a box with HI/LO i thought they only made one gear reverse rotation transfer boxes?

[Mark90]

No I don't belive they do a hi/lo box, just single (interchangable) ratio boxes. This is probably why you don't see many (any?) used outside of racing circles.

[nicksmelly]

Mr Rakeway is designing a reverse rotation transfer box that fits ont he back of a R380 and is high and low ratio.

www.rakeway.co.uk

[saley]

Mr Rakeway is designing a reverse rotation transfer box that fits ont he back of a R380 and is high and low ratio.

www.rakeway.co.uk

That would have saved me a lot of trouble if he had made it 5 years ago

[landybehr]

I fear a completely new t-box may take too much money. A very elegant solution though.

Maybe I could succeed in talkin my friend out of the rear engine.

If not then the "rear-powered" LT230 with flipped diffs will be more work but cheaper. Anyway, it´s up to my friend.

[bill van snorkle]

I fear a completely new t-box may take too much money. A very elegant solution though.

Maybe I could succeed in talkin my friend out of the rear engine.

If not then the "rear-powered" LT230 with flipped diffs will be more work but cheaper. Anyway, it´s up to my friend.

I'm not really into 4wd competition so high speed dirt road handling is not a major consideration to me, but I would have thought from a pure all round crosscountry abilty standpoint, a front end weight bias would be more desirable than a rear bias, as due to weight transfer ,the front axle even on conventional front engined 4x4's can get a bit light on steep hills anyway.

Bill.