Toe in or toe out

[123rover50]

With a leafer that has a constant 4x4 gearbox should it be toe in or toe out and why?
I understand that toe in is for stability in steering straight ahead, however toe out is supposed to turn to toe in under some conditions.
With the constant 4x4 box toe out is recommended however the WSM for the 80" says toe in even with the permanent 4x4 box.
I would like to understand more how it works.

Keith

[rick130]

Ok.

Toe in is generally used on a non driven steering front axle as the wheels tend to be pushed out towards a neutral toe position.
It promotes stability.

Toe out tends to be used on a driven front axle as the driving torque tends to pull the wheels back to a neutral toe position.

Toe out on a RWD car gives sharper turn in (think race and rally cars) but will wander at the straight ahead.

Toe out is never used on a driven rear axle as it makes the rear end totally unstable.
Toe in there gives stability under power.

Toe out on turns (Ackerman) is used on most all mass produced production cars to reduce tyre scrub on turns.

[JDNSW]

Toe in also depends on the camber of the wheels, that is, how far off vertical they are. The camber of all Series vehicles is 1.5 degrees, coil sprung Landrovers are zero.

Where the camber is not zero, but as in this case the wheels lean out at the top, toe in is necessary to prevent tyre scrubbing. Note that because of the king pin inclination and Ackerman geometry, the situation gets more complex once you are off a straight line.

[123rover50]

So with a series with an LT77 cruising along the highway the front axle would not really be driving. I set mine to toe out but maybe toe in should be what I should have. It does tend to wander on some uneven roads.
I might try toe in and see how it feels.

[87County]

toe in a smigen on a Series sounds good

[cjc_td5]

I just used trial and error. By adjusting slightly and then going for a drive I found a balance between wandering in the lane vs heavy steering at parking speeds. Stage 1 series.

[123rover50]

I forgot about the stage one with its LT95.
What does the manual say for it?

[rick130]

Toe in also depends on the camber of the wheels, that is, how far off vertical they are. The camber of all Series vehicles is 1.5 degrees, coil sprung Landrovers are zero.

Where the camber is not zero, but as in this case the wheels lean out at the top, toe in is necessary to prevent tyre scrubbing. Note that because of the king pin inclination and Ackerman geometry, the situation gets more complex once you are off a straight line.

I'm not sure if I agree with that John.

I'm only visualising it but our scrub radius is unchanged, whether you run toe in or out.

At walking pace you will get a little increased scrub with toe out, that's how it increases turn in response at speed, and under power with a constant 4wd the wheels will try to toe in anyway but it doesn't matter where our camber is.

Things like track change through increasing rim offset affect scrub much more.

[goingbush]

The Iveco Daily 4x4 is constant 4x4 Leaf Springs , The book says 1.5 to 2 mm toe in. The book is wrong. The tyres scrub out within a few thousand km. No pre delivery is done on these & some are found to be up to 15mm toe in.

Wheel alignment is a rip off , they set toe in.
The front axle was designed for a part time 4wd tractor , the axle specs Iveco copied are for part time .

Setting 0,5 to 2mm toe Out fixes the scrub issue.

Same translates to LandRover ,
Part Time = Toe in
Constant 4x4 = Toe Out .

[cjc_td5]

I forgot about the stage one with its LT95.
What does the manual say for it?The stage 1 supplement manual says 1.2-2.5mm toe OUT.

[87County]

The stage 1 supplement manual says 1.2-2.5mm toe OUT.

yes - as above - that's 'cause they're constant 4WD

[timax]

The other problem with toe out is when you hit the anchors hard you get even more toe out and the car will be all over the place. Fun in a panic stop.
What tyres are you running?
Do cross ply's have anything to do with what it says in the manual?
I know it makes a difference to camber settings. Less being required than radials.

[cjc_td5]

The other problem with toe out is when you hit the anchors hard you get even more toe out and the car will be all over the place. Fun in a panic stop.
What tyres are you running?
Do cross ply's have anything to do with what it says in the manual?
I know it makes a difference to camber settings. Less being required than radials.Is that question to me mate?
I run 235/85R16 radials on disco steel rims.
The manual does not differentiate between tyre types.

[rick130]

The other problem with toe out is when you hit the anchors hard you get even more toe out and the car will be all over the place. Fun in a panic stop.
What tyres are you running?
Do cross ply's have anything to do with what it says in the manual?
I know it makes a difference to camber settings. Less being required than radials.


And your Defender is running toe out.

Is it an issue under brakes? [wink11]

[timax]

Is that question to me mate?
I run 235/85R16 radials on disco steel rims.
The manual does not differentiate between tyre types.
Possibly because they were originally fitted with cross ply tyres ? Just guessing here. What is the age of the car?
I only have experience with changing toe out settings for the racetrack . Comes down to car /tyre combo and what im comfortable with.
For example. Alfa GTV6 on radials i like 5mm toe out and 2 degrees negative camber. Better turn in with less understeer but dont let go of the wheel.
My PRB clubman on Cross-ply was zero toe and zero camber and with Radials zero toe and 1.5 degree negative camber.
Personally id just adjust toe to feel and camber to tyre ware .

[timax]

And your Defender is running toe out.

Is it an issue under brakes? [wink11]
My Defender is running toe in. How much i have no idea. Its fine under brakes , well for a Defender at least.

[goingbush]

My Defender is running toe in. How much i have no idea. Its fine under brakes , well for a Defender at least.


ALL Defenders need toe OUT , unless of course you have a 2wd / part time conversion

[goingbush]

The other problem with toe out is when you hit the anchors hard you get even more toe out and the car will be all over the place. Fun in a panic stop.
<snip>.


umm no, well maybe if your TRE , swivels or wheel bearings are stuffed , and thats not going to help your braking if you have Toe In.

Sorry that I keep referencing Iveco on a LandRover site but, they are legendary for having the worst brakes of any vehicle ever made and I've modified mine to the extent that it undoubtably has by far the best brakes of ANY Daily 4x4 in the entire universe, it now pulls up in the same distance as a modern family car , it stops exactly where I point it and it has toe out.

[JDNSW]

I'm not sure if I agree with that John.

I'm only visualising it but our scrub radius is unchanged, whether you run toe in or out.

At walking pace you will get a little increased scrub with toe out, that's how it increases turn in response at speed, and under power with a constant 4wd the wheels will try to toe in anyway but it doesn't matter where our camber is.

Things like track change through increasing rim offset affect scrub much more.
Scrub radius is a separate issue. To quote from Wikipedia:-

"When a wheel is set up to have some camber angle (https://en.wikipedia.org/wiki/Camber_angle), the interaction between the tire and road surface causes the wheel to tend to want to roll in a curve, as if it were part of a conical surface (camber thrust (https://en.wikipedia.org/wiki/Camber_thrust)). This tendency to turn increases the rolling resistance (https://en.wikipedia.org/wiki/Rolling_resistance) as well as increasing tire wear. A small degree of toe (toe-out for negative camber, toe-in for positive camber) will cancel this turning tendency, reducing wear and rolling resistance."

I suspect that we are to some extent talking at cross purposes - there are multiple factors affecting what you want to achieve from suspension settings - stability, rolling resistance, steering effort etc. One point I note though when looking on line for more information on this question - nearly all on-line discussion is directed at independent suspension; we are discussing beam axles! At least with beam axles camber and toe do not change with spring deflection (although they do change as soon as you turn the steering wheel!).

[rick130]

Scrub radius is a separate issue. To quote from Wikipedia:-

"When a wheel is set up to have some camber angle (https://en.wikipedia.org/wiki/Camber_angle), the interaction between the tire and road surface causes the wheel to tend to want to roll in a curve, as if it were part of a conical surface (camber thrust (https://en.wikipedia.org/wiki/Camber_thrust)). This tendency to turn increases the rolling resistance (https://en.wikipedia.org/wiki/Rolling_resistance) as well as increasing tire wear. A small degree of toe (toe-out for negative camber, toe-in for positive camber) will cancel this turning tendency, reducing wear and rolling resistance."

I suspect that we are to some extent talking at cross purposes - there are multiple factors affecting what you want to achieve from suspension settings - stability, rolling resistance, steering effort etc. One point I note though when looking on line for more information on this question - nearly all on-line discussion is directed at independent suspension; we are discussing beam axles! At least with beam axles camber and toe do not change with spring deflection (although they do change as soon as you turn the steering wheel!).

Hi John.

I started writing some stuff from my own experience working and modifying race car stuff years ago but it gets so damned complicated suffice to say what you said regarding "there are multiple factors affecting what you want to achieve" is pretty much it.

[rick130]

My Defender is running toe in. How much i have no idea. Its fine under brakes , well for a Defender at least.

Ok, that's unusual, as goingbush said the factory spec is 0-2mm toe out.
Most have found the things are yukky with toe in.

I used to run at least 2mm out on my old 130. It drove dead straight and was never an issue under brakes. I haven't checked the Disco since it became mine.
Probably should. [bigwhistle]

[timax]

Ok , out with the tent pole toe measuring stick it is then.
Thanks gents.

[rick130]

Ok , out with the tent pole toe measuring stick it is then.
Thanks gents.Or a parallel string line down both sides, measure off your hub centerline to get it parallel.
IIRC milk crates were about the right height to hold a bar at each end.