Im thinking of using the engine and gear box from a 1984 Toyoto Tercel 4x4 Estate, which is primarily front wheel drive with driveshafts and selectable 4x4 with a rear propshaft. So should generally be the same as a normal rear wheel drive locost but with front drive shafts as well! Can anyone think of any problems with this idea? being a farmer i want to be able to take it across fields if need to!

heh id say why not if you can

if i was going to do it id leave it in permenent 4x4
if you take it to the track you will definatly see an advantage when it comes to cornering and driving in the wet

thought so! ill just leave the lever in permanent 4x4! only other problem is front suspension, a drive shaft wont get past the shock in springs, or am i wrong? building the mcsorley 7+442, in case ur interested!

Before you decide what you're doing , check the limitations of the gearbox. Pretty sure some of the selectable drive gearboxes have a max speed they can do in 4x4 mode. Something to do with winding the chassis up because of the gearing and wheels going different speeds round corners.

Helloo...

The most important requirement is that the front diff/axle can be placed in front of the engine. If there is a front propshaft and the front diff is relocatable (i.e. not part of the gearbox) then you should be OK. Thats all cos in a Seven the engine is behind the front axle whereas in this Tercel thingy the engine is probably in line with/over the front axle - but having said that I know nothing about Toyota Tercels!

I take it the engine is longitudinal and not transverse?

One thing about that 4WD system: Selectable 2WD/4WD systems like that usually work by locking the front and rear axles together when you engage 4WD mode - i.e. there is no centre differential and hence no speed difference allowed between the front and rear axles in 4WD mode. This means 4WD mode would be unsuitable for road use unless you dont mind the tyres scrubbing all over the place when you go round a corner. But like I said I know nothing about Toyota Tercels, but given its age and if it's like everything else of its kind (old Landrovers etc) that's the way it'll be.

But it will be fine (and fun) for blasting round fields. And for track use it could be OK in 4WD mode too - tarmac spec rally cars have the diffs set up so tight they're practically locked anyway. Reminds me of a time I was helping this guy I know push his tarmac spec Escort Cosworth racer out of his drive onto a trailer - as soon as we dialled on more than 1/4 turn of lock, all the diffs locked up and we couldn't move it an inch. In the end we had to move the trailer perpendicular to the drive (i.e. blocking the road) to get it on .

Well, looks like its measuring time. Good luck! Yet another 4x4 Locost in the working...

Liam

Oh yeah, the front suspension - obviously you'll have to move the shocks out of the way of the front driveshafts! Easiest way is to offset the shocks to the front/rear (and you'll need custom modified wishbones) or mount them inboard like I'm doing.

For more 4x4 headache related discussion look at the '4x4 uprights and Fiesta balljoints' thread under 'running gear'. Or do a search for 4x4 to drag up older ramblings. Definately go to Ewan's website which is here: http://www.geocities.com/ewanspence/. Er go to mine when I make it.

You're not alone - although everyone else doing a 4x4 Seven seems to use Sierra XR4x4/Cossie 4x4 running gear. But hey maybe that's just cos they haven't heard of Toyota Tercels

Liam

Hmmm. Did I scare him off?