Auto mechanics Paper 2 WASSCE (PC 2ND), 2018

Question 3

 

(3)        The sketch shown below is a propeller shaft. 
           

 

(a) State the purpose of the propeller shaft.
(b) Name the parts labelled K, L, M and N.
(c) (i) State the function of the part labelled M.
(ii) State how the part labelled L is protected from dirt and water.
(d) List three components which form the differential unit of the final drive.
(e) State the purpose of the halfshaft.

Observation

 

. (a) The purpose of a propeller shaft is to connect the output shaft of the gearbox to the pinion shaft of the final drive mechanism.  It also transmits the drive (torque) from gearbox to the final drive.   

          
(b) The parts labelled K, L, M, and N are:

K:  Cross or spider
L:  Splines
M: Sliding joint
N: Yoke 

                       
(c)  (i) The function of the part labelled M is to alter the length of the propeller shaft
without interfering with the transmission of the torque.                                        
OR
To allow the deflection of the propeller shaft when the vehicle enters into a pot-hole or moves over bump.             

 
(ii) The part labelled L is protected from dirt and water by a cork oil seal secured by a knurled nut.

(d) The components are:

-  Sun gear or sun wheel;
-  Planet gear or planet wheel;
-  Spider shaft;
-  Differential case

 (e) The halfshaft transmits the drive from the differential unit to the driving wheel.