Bell Crank Suspension and Its Spare Parts

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Categories: Truck Spare Parts

There are two types of suspension which are generally used in Indian trucks –  Boggi/ Bogie suspension and Bell crank suspension or Push Rod suspension. Boggi/ Bogie suspension is generally used in Medium Commercial Vehicles (MCV) that is vehicles with weight capacity below 25 Tonnage and Bell Crank Suspension is generally used in Heavy Commercial Vehicles (HCV) that is vehicles with weight capacity above 25 Tonnage.

The first question is “What is Bell crank suspension?

Bell crank suspension or push rod suspension is generally used in 10 wheeler/ 12 wheeler / 14 wheeler / 16 wheeler tyre vehicles which have tonnage capacity of 25 Ton, 31 Ton and 47 Ton. It is used in Multi axle trucks or trucks with tandem axles (which have dummy rear axles attached with the front/ main drive axle). It is used to divide equal load between both rear axles and keeping both on the ground if any road irregularity occurs. Trucks like TATA 2518, Ashok leyland 2518, TATA prima, Leyland 4018, Leyland Cargo,  etc  use bell crank suspension. Bell crank suspension is something like this. It uses a Bell Crank Levers which along with the connecting rods which is attached to the Lever and manages the front and rear axles for load balancing when brakes are applied by the driver or when a vehicle hits potholes or speed breakers.

Some important parts in a bell crank suspension are:-

  1. Bell Crank lever or Ghodha – Bell crank is something with “a lever with two arms which have a common fulcrum at their junction”. It manages and balances the weight between the front/ main drive and rear axles. Some youtube videos for checking how Bell crank lever along with connecting rod functions (in a dummy/ diagram setting) in a bell crank suspension : https://www.youtube.com/watch?v=pSArG07naiU
  2. Bell Crank Bush/ Sleeve/ Bushing –  Bell crank Bush or Bell Crank Sleeve or Bell Crank Bushing are made of brass and are used as inserts in the Bell Crank lever as shown below and they help in connecting and movement of bell crank pins and  connecting rods. Bell Crank buses are of different height and diameter depending on the Bell Crank Lever insert diameter and length . Some of the various bell crank bush models are:-
    Bell Crank Bush TATA 2416 – T1204
    Bell Crank Bush Leyland 2416 – T1212
  3. Bell Crank Pin/ Bell Crank Shaft – Bell Crank Pin/ Shaft is the rotating part that sits inside the holes of the Bell crank lever and helps in movement of the connecting rod. It is made of iron and to ensure proper fitting the length and diameter must be of proper size. Depending on the vehicle make and model, there are different sizes of bell crank pin. Most running sizes pin are in 35mm & 42mm diameter. Some common sizes of are :- 
    1. Bell Crank Pin 42mm
      1. Kamani/ Bell Crank Pin 42 mm x 110 mm
      2. Kamani/ Bell Crank Pin 42 mm x 116 mm
      3. Kamani/ Bell Crank Pin 42 mm x 123 mm
      4. Kamani/ Bell Crank Pin 42 mm x 131 mm 
      5. Kamani/ Bell Crank Pin 42 mm x 148 mm
      6. Kamani/ Bell Crank Pin 42 mm x 160 mm
    2. Bell Crank/ Kamani Pin 35mm
      1. Rear Kamani/ Bell Crank Pin 35 mm x 129 mm 
      2. Rear Kamani/ Bell Crank Pin 35 mm x 135 mm
      3. Rear Kamani/ Bell Crank Pin 35 mm x 140 mm 
      4. Rear Kamani/ Bell Crank Pin 35 mm x 149 mm 
      5. Rear Kamani/ Bell Crank Pin 35 mm x 151 mm
      6. Rear Kamani/ Bell Crank Pin 35 mm x 164 mm
    3. Bell Crank Pin 25mm
      1. Kamani/ Bell Crank Pin 25 mm x 135 mm
    4. Bell Crank Pin 30mm
      1. Kamani/ Bell Crank Pin 30 mm x 165 mm (u truck) 
      2. Front Kamani Pin 30 mm X 130 mm
    5. Spring Pin/ Shackle (Small vehicles)
      1. Spring Pin 407 O/M
      2. Spring Pin Ace Single Nut
      3. Spring Pin Ace Double Nut
      4. Shackle pin 207 single nut  22×110
      5. Shackle pin 207 double nut  22×130
      6. Shackle pin maxx head side hole 22×100
      7. Shackle pin jeep medium
      8. Shackle pin pickup 22×100 nut side hole 
  4. Bell Crank Washers – Bell Crank washers are iron washers which are used for play of extra space for movement of other parts like connecting rod, leaf spring etc. Bell Crank Washers are important as the maintain the play required for movement in rigid parts like leaf spring, bell crank pin etc. Various bell crank washers sizes are:
    1. Bell Crank Washer 42 dia (Outerdia/ innerdia/ height)
      1. Bell Crank Washer 74 mm X 42 mm X 3 mm – T3465
      2. Bell Crank Washer 74 mm X 42 mm X 4 mm
      3. Bell Crank Washer 74 mm X 42 mm X 5 mm
      4. Bell Crank Washer 74 mm X 42 mm X 6 mm
      5. Bell Crank Washer 74 mm X 42 mm X 7 mm
      6. Bell Crank Washer 74 mm X 42 mm X 8 mm
      7. Bell Crank Washer 70 mm x 42 mm X 4 mm – T3521
      8. Bell Crank Washer 70 mm x 42 mm x 5 mm – T3522
      9. Bell Crank Washer 70 mm x 42 mm x 6 mm – T3523
      10. Bell Crank Washer 70 mm x 42 mm x 7 mm – T3524
    2. Bell Crank/ kamani Washer 35 dia
      1. Bell Crank/ Kamani Washer 74 mm X 35 mm X 3 mm – T3466
      2. Bell Crank/ Kamani Washer 74 mm X 35 mm X 4 mm 
      3. Bell Crank/ Kamani Washer 74 mm X 35 mm X 5 mm
      4. Bell Crank/ Kamani Washer 74 mm X 35 mm X 6 mm
      5. Bell Crank/ Kamani Washer 74 mm X 35 mm X 7 mm
      6. Bell Crank/ Kamani Washer 70 mm X 35 mm x 4 mm
      7. Bell Crank/ Kamani Washer 70 mm X 35 mm x 5 mm
      8. Bell Crank/ Kamani Washer 70 mm X 35 mm x 6 mm
      9. Bell Crank/ Kamani Washer 70 mm X 35 mm x 7 mm
    3. TATA Kamani/ Bell Crank Washer
      1. Kamani Washer TATA Rear 3 mm – T3467
      2. Kamani Washer TATA Rear 4 mm
      3. Kamani Washer TATA Rear 5 mm 
      4. Kamani Washer TATA Rear 6 mm
      5. Kamani Washer TATA Front 3 mm – T3468
      6. Kamani Washer TATA Front 4 mm
      7. Kamani Washer TATA Front 5 mm
      8. Kamani Washer TATA Front 6 mm
      9. Kamani washer Ace (Steel) 16 mm x 34 mm x 2.8 mm
    4. Bell Crank/ Kamani Washer 407
      1. Kamani Washer 407 4mm
      2. Kamani Washer 407 5mm
      3. Kamani Washer 407 6mm
    5. Bell Crank/ Kamani Washer 608
      1. Kamani Washer 608 4mm
      2. Kamani Washer 608 5mm
      3. Kamani Washer 608 6mm
  5. Connecting rod – Connecting rod connects the bell crank lever with the front and rear axle. Connecting rod facilitates movement of the bell crank lever and assists in weight balancing.
  6. Leaf spring – Also called as Kamani Patta. It holds the vehicle down and provides for a smoother ride by absorbing bumps and shocks while driving. Leaf springs are also used to hold the front and rear axle and control the height at which the truck rides and helps keep the tyres aligned on the road.