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Escort Cabriolet Club

Who Knows Thier Gearboxes


Guest benny
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the rst series one had a built in lsd, which the cab didnt?

now!! to my knowledge this allows boths wheels to spin independantaly? is this right? to give the power to which ever wheel needs it the most?

because....

i had one wheel on grass the other day and the other on tarmac, the one on grass was spinning like a motha, but the other just grip and dragged me along, does this mean i got a rst box in? or am i fick?

can sum one explain my dumbness!

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the rst series one had a built in lsd, which the cab didnt?

now!! to my knowledge this allows boths wheels to spin independantaly? is this right? to give the power to which ever wheel needs it the most?

because....

i had one wheel on grass the other day and the other on tarmac, the one on grass was spinning like a motha, but the other just grip and dragged me along, does this mean i got a rst box in? or am i fick?

can sum one explain my dumbness!

 

I'd say you have an rs gearbox mate. An LSD allows the diff to operate like a normal one, till one wheel spins excessively more than the other. Once that happens the clutches inside lock it so both wheels spin the same speed, thus giving the power to the wheel with the grip. :biggrin:

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Guest andybessent

hi im a bit rusty on my gearboxes so ill have to check my books but if i remember correctly a normal diff will allow both wheels to spin at different rates but will always supply each wheel with the same amount of torque and a limited slip diff will lock both wheels together if one starts to spin excessively faster than the other. so if the one on the mud is spinning fast and the otherones slowly pulling the car along id say its just got a normal diff. hope this helps

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Guest turbosy
hi im a bit rusty on my gearboxes so ill have to check my books but if i remember correctly a normal diff will allow both wheels to spin at different rates but will always supply each wheel with the same amount of torque and a limited slip diff will lock both wheels together if one starts to spin excessively faster than the other. so if the one on the mud is spinning fast and the otherones slowly pulling the car along id say its just got a normal diff. hope this helps

You are correct!

 

LSD = both wheels drive/spin at the same speed

 

Non LSD = wheels drive/spin independantly

 

If you want to test if you have a LSD 'box, jack the front of the car up so both wheels are OFF the ground. Spin a wheel, either way. The opposite wheel should go the same way if you have LSD, if it goes the opposite way, you have a non LSD 'box.

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Guest turbocabbie

As the name implies, it is designed to limit slip... it does this by using a secondary mechanism to transfer power back to the slower wheel when a large difference in speed exists between the wheels. There are several ways to accomplish this transfer, and the most common types are the clutch-type and viscous-type LSD.

 

Viscous-type limited slip differentials

A viscous-type LSD uses a thick fluid sandwiched between plates, one plate being connected to (drives) each wheel. When a rotation difference occurs between wheels, the faster plate spins the fluid which in turn spins the slower plate, hence transferring power from the faster wheel to the slower wheel.

A viscous-type LSD has the advantage of requiring little to no maintenance, since the fluid never wears out. However, from a performance standpoint, a viscous-type LSD is not ideal. On a viscous LSD, it takes a split-second for the LSD to react to slip as the fluid must speed up before it starts turning the slower plate. On higher horsepower cars, any lag in response resulting in uneven traction is especially undesirable.

 

A viscous-type LSD is often used as the center differential on AWD cars, where the delay in the transfer of power (from front to back) is not as critical. It is also often used in OEM applications where cost, ease of maintenance and quiet operation is important.

 

Clutch-type limited slip differentials

A clutch-type LSD uses a set of clutch discs, that are connected to each wheel, and the discs are clamped together at a certain pressure when in operation. When one wheel tries to rotate faster than the other wheel, the clutch discs start to slip, the faster disc transfers power to the slower disc through friction, hence transferring power from the faster wheel to the slower wheel.

A clutch-type LSD responds immediately to any slippage, unlike the viscous-type LSD, and is so better from a performance standpoint. A clutch-type LSD is also much more easily upgradeable to handle high horsepower, as the number of clutch discs can be easily increased or the clutch disc sizes can be enlarged. Most aftermarket clutch-type LSDs have larger/more clutch discs. The downside with a clutch-type LSD is that with the slipping of the clutch discs, they eventually wear down and will require maintenance. Also clutch discs will chatter when they are engaged, so a clutch-type LSD is not as quiet as other LSD

Clutch-type LSDs are often offered as 1-way, 2-way or 1.5-way. A 1-way LSD only engages the clutch discs only on acceleration, while a 2-way LSD engages the clutch discs on both acceleration and deceleration. If the clutch discs work to limit slip on deceleration, they can optimize traction under braking, but at the same time as they transfer power from the faster wheel to the slower wheel, this increases oversteer in turns. Therefore a 2-way LSD is generally considered more difficult to handle, but superior for handling, while a 1-way LSD is more forgiviing. A 1.5-way LSD is a compromise between a 1-way and 2-way, as it engages the clutch discs with less pressure on deceleration, which allows for more slip on deceleration and hence less overstee

Gear-type limited slip differentials

 

Finally there are other limited slip differentials that work through gears to limit slip. These LSDs can offer very immediate response like a clutch-type LSD, with little maintenance and quiet operation. However, there are not as easily upgraded for high horsepower as with the clutch-type LSD, they are limited by the strength of their gears. Gear-type LSDs are also generally a lot more costly than the clutch-type or viscous-type LSDs.

 

Simplest way to tell if you have an LSD is to jack your car up and rotate one of the wheels in the forward direction. If the opposite wheel travels in the same direction you have LSD, if it rotates opposite you do not.

 

Hope that helps.. :closedeyes:

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