K. J. Somaiya College of Engineering, Mumbai-77

(Autonomous College Affiliated to University of Mumbai)

Study Report on Clutch used in

Mahindra Scorpio CRDE

The clutch is intended for general starting of the automobile from rest,

disconnecting the engine from the transmission in order to shift gears, and

for avoiding the effect of large dynamic loads on the transmission which appear in

transient conditions and on moving on

different types of roads.

The type of clutch in the car is:

Single plate clutch is of dry type.

Hydraulic Actuation. Weight of the clutch: 5kg

Lubricants and capacities:

Lubricant: MAHINDRA “MAXIMILE DOT

4”

Capacity: 0.9 liters

Remarks: In emergency situations, brake fluid meeting SAE J1703; FMVSS No.116 DOT 4 or IS 8654 Type-2 specification and change at 30,000 km or 2 years whichever earlier.

Single-disc dry clutches

are simple in making and

servicing; they are reliable

and noted for sufficiently

good disengagement and

ensure effective heat

removal from friction pairs.

They have small mass and

high wear resistance.

About 65% of the clutch

plate area is faced on both

sides with friction material.

For consideration, a typical passenger car clutch plate area with a 10 inch diameter

would have a band of friction material of 4in wide along its outer portion.

Wet clutches tend to have multiple plates and they run in oil whereas Dry

clutches tend to be bigger in diameter and have one plate and run in air. There isn’t

much difference in their performance. Mostly the wet clutch is used in bikes. Other

than that, the weight is the issue. The dry clutch tends to be of lighter weight as it

is mostly equipped with single plate clutch.

Especially bikes like Ducati and BMW are still using Single Plate Dry Clutch

because of less weight, more efficiency, less leakages. So their performance on the

racetrack is better.

Now, what is actually hydraulic actuation system for clutch?

On models with hydraulic clutch activator, the system reservoir should be kept

filled with the oil to the correct level. The only lubricated part of this type of clutch

is “throw-out bearing”.The Clutch operation is accomplished either mechanically

or with a hydraulic pressure system.

If a vehicle has a mechanically operated linkage, it will incorporate either a shaft-

and-lever linkage arrangement or a cable.

On a hydraulically operated clutch, a master cylinder is usually directly operated

by the clutch pedal assembly. A slave cylinder at the transmission is connected to

the master cylinder by high-pressure tubing. The slave cylinder pushes either an

operating lever or directly on the release bearing.

Advantages of hydraulic actuation system:

Hydraulic systems require less pedal pressure and provide a smooth “liquid”

feel to clutch engagement.

Design configuration is very flexible and can very easily be adapted to most

any required configuration.

References:

[1] Mahindra_scorpio_owner_manual.

[2] Single plate clutch assembly (https://grabcad.com/library/single-plate-clutch-11)

[3] Clutch plates (http://www.motrpart.in/d/581/mahindra-mahindra-ltd-/clutch-plate)

[4] Specifications of clutch plates (http://www.amazon.in/Valeo-404589-Clutch-Mahindra-

Scorpio/dp/B00PTN6JQ2/ref=sr_1_19?s=automotive&ie=UTF8&qid=1437401579&sr=1-

19&keywords=clutch+plate)

[5] http://www.motoringassist.com/motoring-advice/car-maintenance/engine-and-transmission/guide-

clutch-faults-part-2/

[6] https://answers.yahoo.com/question/index?qid=20130420151318AAmGL9c

[7] Don M. Pirro, Ekkehard Daschner, Book on lubrication Fundamentals

(https://books.google.co.in/books?id=CgsHANZuz-

4C&pg=PA384&lpg=PA384&dq=why+is+lubrication+required+in+dry+single+plate+clutch&source=bl&ots=

b7YPmL-

AaU&sig=OCN8SS5PE_o_chgcEIH24Dgthc4&hl=en&sa=X&ved=0CCMQ6AEwAWoVChMIs9mb0fX3xgIVxRi

OCh34Qg_Y#v=onepage&q=why%20is%20lubrication%20required%20in%20dry%20single%20plate%20clu

tch&f=false)