Locking Diff's - someone help a novice/numpty?
Discussion
Hey guys,
Currently viewing a few cars for my mum and she got her heart set on an '06 Suzuki Gran Vitara. Went along and had a look at it last night and seems a nice car in good shape however, its got changeable diff settings, of which I have no experience. I asked the salesman but his reply was 'don't worry about any of that it never goes wrong, plus you can't lock the diff's on a dry road you'll damage it' - I'm fairly sure that isn't the case?
Anyway heres the dial to control it, can anyone tell me what the N/4H/4H lock/4L lock means and can I safely put it into these settings and drive the car to test its ok? Any ways to spot a duff diff?
Sorry for the daft question, but I'd really appreciate some help!
Thanks
Currently viewing a few cars for my mum and she got her heart set on an '06 Suzuki Gran Vitara. Went along and had a look at it last night and seems a nice car in good shape however, its got changeable diff settings, of which I have no experience. I asked the salesman but his reply was 'don't worry about any of that it never goes wrong, plus you can't lock the diff's on a dry road you'll damage it' - I'm fairly sure that isn't the case?
Anyway heres the dial to control it, can anyone tell me what the N/4H/4H lock/4L lock means and can I safely put it into these settings and drive the car to test its ok? Any ways to spot a duff diff?
Sorry for the daft question, but I'd really appreciate some help!
Thanks
Neutral - Needed if being towed.
4 Wheel Drive - Normal driving mode.
4WD with centre diff locked
4WD low gear
Driving on a tarmac with the latter two selected will 'wind up' the transmission. Over time this can do damage. However over a short distance it will be necessary to test things.
Drive slowly around a curve in 4H mode, then switch in 4H Lock mode and repeat, you should be able feel the transmission start to wind up and want to strongly pull the steering wheel back toward the straight ahead position.
In 4WD low; second gear will feel like first gear when pulling away.
Martin4x4 said:
Neutral - Needed if being towed.
4 Wheel Drive - Normal driving mode.
4WD with centre diff locked
4WD low gear
Driving on a tarmac with the latter two selected will 'wind up' the transmission. Over time this can do damage. However over a short distance it will be necessary to test things.
Drive slowly around a curve in 4H mode, then switch in 4H Lock mode and repeat, you should be able feel the transmission start to wind up and want to strongly pull the steering wheel back toward the straight ahead position.
In 4WD low; second gear will feel like first gear when pulling away.
Perfect, exactly what I was after. Thanks for taking the time to reply.4 Wheel Drive - Normal driving mode.
4WD with centre diff locked
4WD low gear
Driving on a tarmac with the latter two selected will 'wind up' the transmission. Over time this can do damage. However over a short distance it will be necessary to test things.
Drive slowly around a curve in 4H mode, then switch in 4H Lock mode and repeat, you should be able feel the transmission start to wind up and want to strongly pull the steering wheel back toward the straight ahead position.
In 4WD low; second gear will feel like first gear when pulling away.
Cheers
Diffs, a bit of an explanation:
The primary function of a differential is to let a car go around a corner.
Think of a simple rear wheel drive car to begin with. As you're driving the RWD car around that corner, the outer wheel has to travel further than the inner wheel. Therefore, the outer wheel has to travel faster than the inner. The differential is what sorts this all out for you.
However, the differential is lazy... It will always transmit the power through the path of least resistance. If that RWD car has an 'open' differential and you lift one of the drive wheels off the ground, all the power will be lost through that one wheel.
Locking the differential means it will blindly send the power to both wheels. You'll lose 50% of the power, through the wheel lifted off the ground but the wheel on the ground will drive the car forwards. However, whilst the differential is locked, it won't go around corners cleanly due to 'transmission wind-up'. That's why you have the ability to lock/unlock diffs.
What about 4WD...
On a 4WD car, you'll need a differential on the rear axle but you're also going to need a differential on the front axle. However, when you drive a 4WD car around that corner, the front axle turns at a slightly different speed to the rear axle... So you're going to need a 3rd differential between them.
Most 4WD cars have the ability to lock the centre differential. Once locked, it is now 'blindly' sending power 50/50 to both the front & rear axles. In this mode, if wheels on 1x axle start to slip, the other axle continues to push/pull the car through.
BTW - Traction Control essentially works by providing resistance (remember 'path of least resistance'). If it spins a wheel, this will be detected and brakes will be applied to provide resistance. Once the resistance is there, the power is delivered to the wheel with grip.
That's a 'high level' description. You can go on to talk about high vs low friction surfaces... Different types of differential... Torque... Traction Control... Blah... Blah... But I won't for now.
M
The primary function of a differential is to let a car go around a corner.
Think of a simple rear wheel drive car to begin with. As you're driving the RWD car around that corner, the outer wheel has to travel further than the inner wheel. Therefore, the outer wheel has to travel faster than the inner. The differential is what sorts this all out for you.
However, the differential is lazy... It will always transmit the power through the path of least resistance. If that RWD car has an 'open' differential and you lift one of the drive wheels off the ground, all the power will be lost through that one wheel.
Locking the differential means it will blindly send the power to both wheels. You'll lose 50% of the power, through the wheel lifted off the ground but the wheel on the ground will drive the car forwards. However, whilst the differential is locked, it won't go around corners cleanly due to 'transmission wind-up'. That's why you have the ability to lock/unlock diffs.
What about 4WD...
On a 4WD car, you'll need a differential on the rear axle but you're also going to need a differential on the front axle. However, when you drive a 4WD car around that corner, the front axle turns at a slightly different speed to the rear axle... So you're going to need a 3rd differential between them.
Most 4WD cars have the ability to lock the centre differential. Once locked, it is now 'blindly' sending power 50/50 to both the front & rear axles. In this mode, if wheels on 1x axle start to slip, the other axle continues to push/pull the car through.
BTW - Traction Control essentially works by providing resistance (remember 'path of least resistance'). If it spins a wheel, this will be detected and brakes will be applied to provide resistance. Once the resistance is there, the power is delivered to the wheel with grip.
That's a 'high level' description. You can go on to talk about high vs low friction surfaces... Different types of differential... Torque... Traction Control... Blah... Blah... But I won't for now.
M
camel_landy said:
Diffs, a bit of an explanation:
The primary function of a differential is to let a car go around a corner.
Think of a simple rear wheel drive car to begin with. As you're driving the RWD car around that corner, the outer wheel has to travel further than the inner wheel. Therefore, the outer wheel has to travel faster than the inner. The differential is what sorts this all out for you.
However, the differential is lazy... It will always transmit the power through the path of least resistance. If that RWD car has an 'open' differential and you lift one of the drive wheels off the ground, all the power will be lost through that one wheel.
Locking the differential means it will blindly send the power to both wheels. You'll lose 50% of the power, through the wheel lifted off the ground but the wheel on the ground will drive the car forwards. However, whilst the differential is locked, it won't go around corners cleanly due to 'transmission wind-up'. That's why you have the ability to lock/unlock diffs.
What about 4WD...
On a 4WD car, you'll need a differential on the rear axle but you're also going to need a differential on the front axle. However, when you drive a 4WD car around that corner, the front axle turns at a slightly different speed to the rear axle... So you're going to need a 3rd differential between them.
Most 4WD cars have the ability to lock the centre differential. Once locked, it is now 'blindly' sending power 50/50 to both the front & rear axles. In this mode, if wheels on 1x axle start to slip, the other axle continues to push/pull the car through.
BTW - Traction Control essentially works by providing resistance (remember 'path of least resistance'). If it spins a wheel, this will be detected and brakes will be applied to provide resistance. Once the resistance is there, the power is delivered to the wheel with grip.
That's a 'high level' description. You can go on to talk about high vs low friction surfaces... Different types of differential... Torque... Traction Control... Blah... Blah... But I won't for now.
M
thanks for this, now I know. cheersThe primary function of a differential is to let a car go around a corner.
Think of a simple rear wheel drive car to begin with. As you're driving the RWD car around that corner, the outer wheel has to travel further than the inner wheel. Therefore, the outer wheel has to travel faster than the inner. The differential is what sorts this all out for you.
However, the differential is lazy... It will always transmit the power through the path of least resistance. If that RWD car has an 'open' differential and you lift one of the drive wheels off the ground, all the power will be lost through that one wheel.
Locking the differential means it will blindly send the power to both wheels. You'll lose 50% of the power, through the wheel lifted off the ground but the wheel on the ground will drive the car forwards. However, whilst the differential is locked, it won't go around corners cleanly due to 'transmission wind-up'. That's why you have the ability to lock/unlock diffs.
What about 4WD...
On a 4WD car, you'll need a differential on the rear axle but you're also going to need a differential on the front axle. However, when you drive a 4WD car around that corner, the front axle turns at a slightly different speed to the rear axle... So you're going to need a 3rd differential between them.
Most 4WD cars have the ability to lock the centre differential. Once locked, it is now 'blindly' sending power 50/50 to both the front & rear axles. In this mode, if wheels on 1x axle start to slip, the other axle continues to push/pull the car through.
BTW - Traction Control essentially works by providing resistance (remember 'path of least resistance'). If it spins a wheel, this will be detected and brakes will be applied to provide resistance. Once the resistance is there, the power is delivered to the wheel with grip.
That's a 'high level' description. You can go on to talk about high vs low friction surfaces... Different types of differential... Torque... Traction Control... Blah... Blah... But I won't for now.
M
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