Automatic Gears

[gsgtsg]

Please excuse my ignorance.
I have always driven my V8 Discovery in gear D, and was wondering when the gears 1, 2 & 3 are used and upto what speeds.

Thank you.

[bananahead]

only used 1 2 or 3 when offroad. When descending very steep incline i would use 1 or 2 so it would not change up on its own, and engine braking would stop the car flying down the hill really fast and into a tree.

[Satancom]

If its like all the other autos i have driven it will be like this

1.. Car will stay in first gear unles syou do something with the stick
2.. Car stays in second and pulls away in second (use in the snow mostly)
3.. will go through all the gears but will not go into over drive, or fourth..

Something like that. Drive in D for normal driving :)

[kevinrbeech]

1, 2 & 3 are to lock it in that gear, 1st, 2nd or 3rd. As said above useful off road, also, you may want to stay in 2nd when towing something heavy uphill, where the car keeps jumping from 2nd to 3rd and then back to 2nd every few minutes. When trying to pull away in snow, or mud maybe, sometimes you will get more traction by using 2nd to pull away.
The list goes on. I'm sure you'll get more replies.
Kevin

[Widget]

Not quite boys...just spoken to a chum with a Disco 2 V8 auto and its the same as mine apparently.

1 holds it in 1st gear.
2 allows selection of 1 and 2, and prevents change up into 3rd and 4th.
3 allows selection of 1 and 2 and 3, and prevents change up into 4th.


3 is useful around town when you don't want it to change up into 4th to improve responsiveness.
2 comes into its own in hilly areas, or when towing in hilly spots. Not only is responsiveness improved, torque converter slip is minimised which prevents the transmission fluid from overheating.
2 is handy to improve on road engine braking.


In low range you need to use manual gear selection in an auto. When you risk losing traction (e.g. in mud or on rocky sections) the gearbox will select a higher gear if traction is lost. This is a good thing because torque is reduced at the wheels when a higher gear is selected, limiting slip. But of course, changing up a gear reduces momentum too - and sometimes you need to use wheelspin to get through the gunge - in which case limiting the upchanges is a good thing to keep going.

In low range I shift between D and 3rd regularly , this limits torque converter slip and gives me more control with the throttle.

Then there's descending. Select 1 and scream.

And everyone thought Autos were easy - but as with all things there's techniques to learn.

[Satancom]

Then there's descending. Select 1 and scream.

And everyone thought Autos were easy - but as with all things there's techniques to learn.

Watching you go down the GAP is quite amusing :p

Cheers for clearing it all up, guess some autos are a bit different.

[gsgtsg]

1) Can the gears be shifted between D, 1, 2 and 3 whilst the vehicle is moving, or does it need to be stationary?
2) Also, what is the maximum speed to drive at when in these gears?

[Satancom]

You can shift between gears whilst moving.. but obviosuly only if the rev range is suitible for the speed :)

[graham]

Not quite boys...just spoken to a chum with a Disco 2 V8 auto and its the same as mine apparently.

1 holds it in 1st gear.
2 allows selection of 1 and 2, and prevents change up into 3rd and 4th.
3 allows selection of 1 and 2 and 3, and prevents change up into 4th.

3 is useful around town when you don't want it to change up into 4th to improve responsiveness.
2 comes into its own in hilly areas, or when towing in hilly spots. Not only is responsiveness improved, torque converter slip is minimised which prevents the transmission fluid from overheating.
2 is handy to improve on road engine braking.
In low range you need to use manual gear selection in an auto. When you risk losing traction (e.g. in mud or on rocky sections) the gearbox will select a higher gear if traction is lost. This is a good thing because torque is reduced at the wheels when a higher gear is selected, limiting slip. But of course, changing up a gear reduces momentum too - and sometimes you need to use wheelspin to get through the gunge - in which case limiting the upchanges is a good thing to keep going.

In low range I shift between D and 3rd regularly , this limits torque converter slip and gives me more control with the throttle.

Then there's descending. Select 1 and scream.

And everyone thought Autos were easy - but as with all things there's techniques to learn. just seen this thread, your spot on :)

[Roger Whittle]

1) Can the gears be shifted between D, 1, 2 and 3 whilst the vehicle is moving, or does it need to be stationary?
2) Also, what is the maximum speed to drive at when in these gears?

As Satancom and Graham both point out, you can shift on the move, but you have tio bear in mind the rev range of the gear you select. That's what your tacho is for. There is no red line on mine, which I assume means the engine will self limit, but I seldom go above 3000 rpm in any gear at any time. 3K is over eighty in top. (Sorry, I've just noticed you have the 3.9 V8 - so revs are all different - I'm on a TD5)

No one has mentioned the 'sport' button at the back end of the selector slot. This doesn't give you any more power - chance would be a fine thing - but it does change the way the gearbox operates. In normal mode, the gearbox will change more or less at a given speed. In 'sport' mode, it removes all the speed presets and changes gear at a set engine speed, say 2500 or 3000 rpm. (See apology above.)

It also changes the kickdown mode. In normal, kickdown will change down to the next gear down. In sport mode, it will kick down to the lowest available gear. All a bit unnecessary, if you ask me - I never use kickdown, ever. I prefer to control my autobox myself.

I allow it to change up automatically, but I often use manually selected 3rd for descending or slowing up in traffic, sometimes as low as 2nd on a steep hill. This increases the engine braking, which is negligable in higher gears.

In low ratio, the gearbox mode changes as does the throttle response - it is a 'fly-by-wire' throttle and its quite tricky to got used to the way it responds in low box. I cannot confirm what has been said about the way the selector works in low box. I think it will operate automatically in 'D', but if you use the selector, it will stay in the gear you select. So, in high box, selecting 3rd will start in first and change automatically until it gets to 3rd and then stay there. In low box, if you select 3rd it will start in 3rd and stay that way. Good for snow and ice and very slippery mud.

The question is, have you got diff lock? Look at your transfer box selector and see if the centre position has a branch to the left marked 'Diff'. Some models do and some do not. You will have TC (traction control - a function of ABS) in any case. Also HDC. Hill descent control - available in low box only, but a bit scary to use.

Roger.

[Dave78]

As Satancom and Graham both point out, you can shift on the move, but you have tio bear in mind the rev range of the gear you select. That's what your tacho is for. There is no red line on mine, which I assume means the engine will self limit, but I seldom go above 3000 rpm in any gear at any time. 3K is over eighty in top. (Sorry, I've just noticed you have the 3.9 V8 - so revs are all different - I'm on a TD5)

On the new gearboxes the electronics should take care of all of that. If you try to select a gear which if selected would damage the engine (rev too high) it shouldn't select it... That said I've never really tried it out - not brave enough to take a Range Rover back to my boss saying I think I broke it

[Satancom]

My scooby wont shift unless its safe to do so.. but it has this really scary button that will overide the computer and shift to whatever you say, ignoring redline etc :S I have pressed it once to see if the light worked!

[shten]

One more thing to note that has not been mentioned yet.
(this is the case for my D2 TD5 ES not sure if it applies to you too)
When in low range hitting the Mode button on the gearbox puts it into a manual mode which will keep it in the specified gear as long as the engine wont stall doing so (otherwise the auto box will down change to prevent stall then go back when it can). It uses D as forth. There are lots of juicy details and helpful info in my manual which helped me a lot to understand it all. There is an online copy in the owners section on the LR website.

I mainly use the 1,2,3 for engine braking..
One can use 3 to force a down change when overtaking.


Quick summary of how I understand the whole thing (sorry quick is not my middle name)

There are 4 modes for the gearbox

Normal mode High range
Sport mode (High range)
Normal mode Low range
Manual mode (Low range) Widget had the best description of the normal mode operation.

1 holds it in 1st gear.
2 allows selection of 1 and 2, (by auto gearbox) and prevents change up into 3rd and 4th.
3 allows selection of 1 and 2 and 3, (by auto gearbox) and prevents change up into 4th. The Sport mode as mentioned by others is the same as the normal mode just altering when the auto gearbox will decide to change.
The Manual mode is however the only one where the gearbox will try to hold it in the selected gear, as already described.



I hope that helps …

[Widget]

Clearly my friend with the Disco V8 has no idea how to use the mode button for sport and manual gearshifting!

[shten]

Clearly my friend with the Disco V8 has no idea how to use the mode button for sport and manual gearshifting!

I thought you were spot on with your description and uses ..

[Satancom]

Eh.. Auto's are for lazy people (yes I class myself as lazy)

[ROB 110 HICAP]

Then there's descending. Select 1 and scream.

Correction: scream and cr*p yourself:eek:
Thats the only thing I hate about autos offroad, lack of diesel type engine braking. I suppose hill descent button would help as an addition?

[Widget]

I've thought about an underdrive - but use the cheaper left foot braking + throttle technique instead. After all , folk pay good money to travel on roller coasters.

[Roger Whittle]

Correction: scream and cr*p yourself:eek:
Thats the only thing I hate about autos offroad, lack of diesel type engine braking. I suppose hill descent button would help as an addition?


I can't make up my mind if HDC is useful or just gimmicy. It is certainly quite powerful, but a bit fiddly to select and rather 'sudden death' if it suddenly becomes 'inappropriate'. :eek:

For our original questioner, HDC or Hill Descent Control is only available to low box. You select it by being in low box and 'D' with your foot on the footbrake. Press the yellow button and a lamp on the panel lights, accompanied by 'bong - bong' audible warning. Then you take you foot off the brake and let it roll down the hill. :rolleyes:

DON'T TOUCH ANYTHING!!! :eek:

Actually the steering wheel's okay, but don't touch any pedals. It starts off much quicker than you think prudent, but it soon gets a hold of things and will lower you down gently, no matter what the ground under foot is like. Even greasy, wet, moss covered track at 1 in 4 down with a one and a half ton trailer behind - it takes it all in its stride. Meanwhile, your nerves are screaming to get on the brakes, the ABS unit is growling and grinding and individual brakes are going bubb - bubb ..... bubb - bubb - bubb .... bubb. :eek: Its a nightmare the first time you do it.

When you get to the bottom and the rig levels out, the HDC will go bong-bong-bong to remind you it has finished and you should deselect it.

The thing is, if you touch the brakes, the system 'disarms' and will not automatically 'rearm'. From that moment on - you are 'on your own pal' and, since it was probably going faster than you would, all four wheels will lock up and you are on your way to a world of hurt. :D

Oh, by the way, first gear in low box is very low and will almost stop you on most slopes if you lift the throttle. You seldom have to use brakes in first-low.

Roger.

[Widget]

Oh, by the way, first gear in low box is very low and will almost stop you on most slopes if you lift the throttle. You seldom have to use brakes in first-low.


Sage advice, but would just point out that with a diesel you have twice the engine compression of a V8 - which is technically the difference bewteen 'wahey' and 'whooooah':D

[thebiglad]

Correction: scream and cr*p yourself:eek:
Thats the only thing I hate about autos offroad, lack of diesel type engine braking. I suppose hill descent button would help as an addition?

I've not done too much yet, but having tried selecting low box and number 1 gear I get all the engine breaking I'm ever going to need - I think ??

[Roger Whittle]

Sage advice, but would just point out that with a diesel you have twice the engine compression of a V8 - which is technically the difference bewteen 'wahey' and 'whooooah':D

Ah, just so. You may well be right JB. :D:D

Roger.

[ROB 110 HICAP]

Sage advice, but would just point out that with a diesel you have twice the engine compression of a V8 - which is technically the difference bewteen 'wahey' and 'whooooah':D

I've not done too much yet, but having tried selecting low box and number 1 gear I get all the engine breaking I'm ever going to need - I think ??

On my Cherokee straight 6 petrol, engine braking is non-existent even in low box, it just screams at about 4000rpm as you shoot down. Luckily only done it on wet grass with a big run off, not rocks with a cliff at the bottom:D