Dumb Question .....

[Red Oktober]

Umm

do i have to stop to change into 4wd ???

obviously i have to press the "Hub lock" and "4wd" buttons on the dash .. but do i have to be stopped to do it ?
and ..... do i have to be stopped to change from 4hi to 4lo ??

 

[Ben]

so long as your hubs are locked you can change into 4 high whilst moving, but you really need to stop to put it in 4 low otherwise the gears will make a nasty crunch sound as they engage.

being able to select 4 high whilst moving can be particularly useful when weve got conditions like snow and ice. i kept my hubs permanently locked when we had all that bad weather, and then kept in 2 high on the tarmac then as soon as i came to some snow or ice id press the 4 high button.

this meant i was able to maintain traction on the slippery stuff, without winding the gearbox up and doing damage when on the dry stuff.

i sometimes use low 2 aswell, by keeping the front hubs unlocked and selecting low range. this can be particularly useful when for example hauling a heavy trailor up a very steep hill, on the road.

 

[Ben]

thinking about it..................................what ive written above is for a manual 70. is yours auto?

if so theres a good chance you will also also be able to go into low whilst moving?

 

[JimmyLJ71]

I have an auto, i would not advise going into low range on the move it does the same as a manual, makes an orrible gearbox grinding noise and with no clutch pedal you aren't disengaging the gearbox, i cant move my low range stick at all unless in neutral.

I also find the low range with unlocked hubs useful i used it in that configuration in the Alps, going up the mountain tracks you needed the low range but not the four wheel drive because the traction was good, i am told you have to be careful though because it puts all the power to the rear axle, if you are towing something very heavy it could cause damage, not heard of it happening on cruisers, but i have on old landys.

 

[Ben]

i wasnt sure if autos had a separate lever for low range or whether they had a button like high range.

it wont/shouldnt be putting all the power to the rear wheels.

on 4x4's that dont have a centre diff lock the power is already split/locked front to back when 4x4 is engaged. so with it in 4 low with the front hubs unlocked the power is split front to back, and on the front the prop, diff and half shafts are turning, but obvioulsy the hubs arnt because there unlocked.

all old landys are full time 4x4 hence why they need centre diff lock.

 

[J66P]

no technical question is dumb if you dont know the answer matey, thats what forums are for

 

[Scott]

it wont/shouldnt be putting all the power to the rear wheels.

Apart from spinning up the front drive train, which takes a very small amount of power, all the power and loading will be going through the rear drive train to the rear wheels. While the front wheels happily spin on their unlocked free wheeling hubs.

on 4x4's that dont have a centre diff lock the power is already split/locked front to back when 4x4 is engaged.

Just in case there's any confusion, it's not that part time 4x4's don't have a centre diff lock, they don't actually have a centre diff at all, hence you can't use the 4 wheel drive on grippy surfaces as the front and rear axles can't turn at different speeds when cornering.

I find people best understand it when you say that, when engaging 4 wheel drive in a part time 4x4, you are joining the front and rear props together as one solid unit. So the front and rear axles are now solidly joined together.

all old landys are full time 4x4 hence why they need centre diff lock.

Stage 1 V8, 90, 110, Range Rover and Discovery are all full time 4x4's. Series 1, 2 & 3 are all part time 4x4 (no centre diff).

So if a series Land Rover has free wheeling hubs fitted, and set in the open position, whilst 4 wheel drive is engaged, all the power and loading will be going through the rear wheels. As Jim mentioned it's in situations like this, when people have managed to blow up rear diffs, or snap rear half shafts on LR's, and he was wondering if people had heard of anyone having similar experiences with 70 series Land Cruisers.

Ben, I'm not being argumentative, it's just easy for people to read stuff and get the wrong end of the stick, and end up even more confused.

Cheers.

 

[JimmyLJ71]

I was going to say the same, but didn't want to cause upset, it was on a series that this happened, not full time four wheel drive, towing a heavy trailer.

 

[Ben]

no problem Scott. im not always right.

 

[Red Oktober]

ok ... mine is an auto.

so if i've got this right .... i can lock the hubs whilst moving and change into 4hi .... but have to be stopped with the selector in N before i can change into 4lo ??

 

[Birder]

My truck has this so the driver can remember, i think it says it all

 

[Red Oktober]

Thanks for that ... i wouldn't have needed to ask if i could read Japanese

 

[Annamarie]

could always learn

 

[Red Oktober]

could always learn

yeah .... right after you have

 

[Roger Fairclough]

so long as your hubs are locked you can change into 4 high whilst moving, but you really need to stop to put it in 4 low otherwise the gears will make a nasty crunch sound as they engage.

being able to select 4 high whilst moving can be particularly useful when weve got conditions like snow and ice. i kept my hubs permanently locked when we had all that bad weather, and then kept in 2 high on the tarmac then as soon as i came to some snow or ice id press the 4 high button.

this meant i was able to maintain traction on the slippery stuff, without winding the gearbox up and doing damage when on the dry stuff.

i sometimes use low 2 aswell, by keeping the front hubs unlocked and selecting low range. this can be particularly useful when for example hauling a heavy trailor up a very steep hill, on the road.

I have substituted solid flanges for the manually locked variety so that 4 wheel drive is instantly available via the dash mounted switch. I have also disconnected the wiring (Daves mod) that connected the low range automatically with 4 wheel drive. This gives high and low range in 2 wheel drive with 4 wheel drive in either via the switch.

Roger

 

[Roger Fairclough]

I have an auto, i would not advise going into low range on the move it does the same as a manual, makes an orrible gearbox grinding noise and with no clutch pedal you aren't disengaging the gearbox, i cant move my low range stick at all unless in neutral.

I also find the low range with unlocked hubs useful i used it in that configuration in the Alps, going up the mountain tracks you needed the low range but not the four wheel drive because the traction was good, i am told you have to be careful though because it puts all the power to the rear axle, if you are towing something very heavy it could cause damage, not heard of it happening on cruisers, but i have on old landys.

The back axle on a cruiser is a lot stronger than the equivalent LR item. You should have no problems using full power on a sealed surface.

Roger

 

[Roger Fairclough]

i wasnt sure if autos had a separate lever for low range or whether they had a button like high range.

it wont/shouldnt be putting all the power to the rear wheels.

on 4x4's that dont have a centre diff lock the power is already split/locked front to back when 4x4 is engaged. so with it in 4 low with the front hubs unlocked the power is split front to back, and on the front the prop, diff and half shafts are turning, but obvioulsy the hubs arnt because there unlocked.

all old landys are full time 4x4 hence why they need centre diff lock.

If the front hubs are unlocked, all the power is going to the back axle. In 2 wheel drive with the hubs unlocked, the internals of the front axle plus the propshaft are stationary, apart from a small movement due to drag, maybe.

Some series 1 landies had full time 4 wheel drive. Most series 1 plus most of the other series were part time 4 wheel drive. I believe some V8 series 3 were full time and all 90's etc were full time.

Roger

 

[Roger Fairclough]

ok ... mine is an auto.

so if i've got this right .... i can lock the hubs whilst moving and change into 4hi .... but have to be stopped with the selector in N before i can change into 4lo ??

Being an auto shouldn't make any difference as it's the transfer box that we are talking about. 2 wheel drive to 4 wheel drive can be accomplished on the move, up to 62 mph, in a straight line, as long as the front hubs are engaged. The speed limit and straight line bit are solely there to allow for any slight differences in tyre dia.

To change from high range to low range requires a change in gearing, and you must be stationary to do it as there is no synchromesh involved. It should be possible to do it by doubling the clutch (double de clutch) but by the time you have done it, you would probably be stationary anyway.

Roger

 

[Birder]

Thanks for that ... i wouldn't have needed to ask if i could read Japanese

"Simpry ask grasshopper"

 

[Roger Fairclough]

If your tyres are approximately the same dia. front to back, then, for short distances, it is perfectly feasible to operate your dash mounted 4 wheel drive button to give you 4 wheel drive on a sealed surface. A classic case is an icy or snow covered road that is in patches. The distances involved will depend on circumstances but a 100 metres should be no problem. On one occasion I inadvertently drove 2 miles on a dry road with 4 wheel drive locked in. There was no damage but I wouldn't suggest that anyone else tries it.

Roger