What is Carraro Axle, What Does it Consıst of?

By Original Parts 4 You Blog Team on Jul 12 2023

How does the axle work?

The operation of the axle in a construction machine is not much different from the axle of a car. It can be called a motor axle because its role is to distribute thrust to the wheels. This is the part that connects the wheels of an axle. It is the drive shafts that are responsible for powering the wheels to rotate on the same axis. In addition to acting as suspension for wheel weights and steering controls. In short, it is the motor that drives the gearbox and then drives the driveshaft. There is a ring between the output shaft and the input shaft. Axle is the important part of the differential. The axle is a straight shaft that is fixed in location , it is combined with bearing orbrushing use to mount rotating wheel or gears. The wheel or gear can be attached to it with a built in gearing or bushing. Abearing or brushing fits inside the center of the wheel and allow it to rotate without affecting the axle itself. The purpose of axleis to secure the wheels or gears to specific locations relative to other wheels or gear. The wheels would not remain fixed in position and the force and vehicle would make the wheel bend flat The power developed by the engine is transferred to the wheels through clutch, gear box, universal joints, propeller shaft, final drive, differential and rear axles.

Which Parts Make up a Axle of Construction Machinery?

Rear Axle

Rear axle transmits power from differential to the wheels so that vehicle may turn. Rear axle isn’t a single part but it consist twoparts which are connected to the differential. Outer end of therear axle carries the wheel while inner end is connected by sun gear of the differential. In vehicles which employ rear wheeldrive, which are driving wheels. However, In front wheel drive vehicles, front wheels are driving wheels. Rear axles anddifferential are completely enclosed in a housing to protected from dirt, dust, water and any accidently damage. In any car or four andsix wheeler vehicles, steering is main part. Properly steering works are good and guides the vehicle to move in actual direction.Manually steering is connected to the front axel. On the front axle, wheels are mounted, and with the help of steering wheel, thedriver can turn the vehicle in right, left or straight directions.

Type Of Rear Axle

Rear axles on the basis of method of supporting them and mounting of rear wheels. These axles can be classified into three types:

  1. Half floating axle
  2. Three-quarter floating axle
  3. Fully floating rear axle

Half Floating Axle :

The half floating rear axle, the axle is at the centre of the axle casing and the bearings are inside the axle casing. The weight of vehicle is transmitted first to suspension spring, then to axle casing, then to axle and finally to ground.

Three-quarter Floating Axle :

The 3-quarter floating rear axle, bearings are on the outer side of axle casing, i.e. between casing and wheel. In this case, major part of vehicle weight is taken by axle casing and not by axle. This is the main advantage of 3-quarter floating type over half floating type. Thus, axle breakdown is less in this case compared to the previous type.

Fully Floating Rear Axle

In fully floating rear axle, the bearings are provided between axle casing and the wheel. In this case, all the vehicle weight is transmitted to ground through axle case and wheel. The axle is not supported by bearings but it is supported at both ends. This type of axle is very strong and therefore, which are used for heavy duty vehicles. In the event of breakdown of axle, Wheel cannot come out.

Front Axle

To carry the weight of the front part of auto mobiles as well as for steering and to absorb shocks due to road surface variation a unit is known as ‘front axle’ In order to accommodate a swivel pin connecting to the stub axle portion of the assembly, the ends of the beam are shaped suitably. Swivel pin connecting the stub axle portion of the assembly, the ends are the beam are usually shaped either as a yoke or plain surface with drilled holes. The axle has to take bending loads due to braking of the wheels. That why front axle made of ‘I-section’ in the central portion and the end portion is made of circular. The main axle beam is connected to the stub axle by means of kings pins. The front road wheels are mounted on these stub axles.

Type of Front Axle

Three types of front axle:

  1. Live-front axle
  2. Live-front axle
  3. Stub-front axle

Live-front Axle

In Live-front axles are used to transmit power from gear box to front wheels. Live-front axle although, front wheels. This axle although resemble rear axles but they are different at the ends where wheels are mounted.  By which the engine power towards the front wheels. For steering the front wheels, constant velocity joints are contained in the axle shafts. Without affecting the power flow through the half shafts, these joint help in turning the stub-axles around the king pin.

Dead-front Axle :

In Dead-front axles are those axles, These axles have sufficient rigidity and strength to take the weight. The ends of front axle are suitably designed to accommodate stub axles. In which there is no connection with the engine and having no differential mechanism. These axle do not rotated with the engine like live-front axle. The front dead axles are four types : 1 Elliot axle, 2 Reverse type, 3 Lemoine, 4 Reversed lamoine type.

Stub-front Axle: :

A stub axle, which is provided in the ends of the axle beam of a front axle. A fixed vertical pin is known as king pin secures the stub axle and its forked arms to the axle and by means of a lock pin passing through a hole in the side of the king pin hole. Thrust should be provided between the lower machine face of each axle hole and the upper face of the stub axle fork hole because the weight of the front portion of the car is to be taken on the lower fork arms of the stub axle. For steering with a minimum of effort, roller thrust bearing is employed. This helps the stub axles to be rotated in rotation to the fixed king-pin. Stub axle are following four types:

  1. Reverse elliot
  2. Elliot stub axle
  3. Reversed lamoine stub axle
  4. Lamoine stub axle

How Tto Repair Carraro Axles? What Should bBe Paid Attention to?

Before starting any disassembly or assembly operations, read carefully the following recommendations.

Shafts oil seals

Observe the following recommendations during shafts oil seals assembly:

Clean thoroughly the shaft and make sure that the parts in contact with the seals are not damaged,scratched or deformed . Do not damage the seals during the assembly of the shaft; assemble the seals so that the lip is fitted towards the oil side . There may be specific applications requiring a different assembly, you should check the existing orientation of the ring before disassembly. If in doubt contact your trusted, lubricate seals lip (use preferably oil) or fill with grease 3/4 of seals cavity ; use an appropriate tool to assemble the seals.

Warning: do not use a hammer directly on the seals. We recommend to use the appropriate tools specially designed and provided by CARRARO.


Lubricate them properly before the introduction in their seat and avoid o-ring “rolling” during the assembly of the shaft.


Observe the following recommendations during bearings assembly:  before reassembly the bearings, clean, check and lubricate them;  replace bearings showing signs of pitting or irregular rotation;  to simplify the assembly you should warm up them in he oven at a temperature of 80-90 °C . before assembly the bearings on their respective shaft or cool them before the introduction in their seats;  always use appropriate tools to remove and assemble the bearings.

Spring pins

Observe the following recommendations during spring pins assembly:  before assembling spring pins make sure the notch is oriented towards the stressing force ;  spiral spring pins do not need orientation.


To clean the axle/transmission:  wash accurately all moving parts with diesel fuel or kerosene;  gasoline and watery alkaline solutions are forbidden; do not wash with steam or hot water, because it would be difficult to eliminate surface humidity;  dry thoroughly all the details with an air jet or rag to avoid scratching the surface with abrasive residuals; after cleaning operations, all the surfaces should be covered with lubricant to protect them from future oxidation.


During the control operations of the axle/transmission observe the following recommendations: check all splines, assure they are not over-wear or damaged; replaced damaged parts with genuine spare parts;  before the reassembly, the seals (both static and dynamic) on rotating shafts and/or closing cover must be replaced;  examine accurately all bearings, external rings which may still be assembled on their seats or other parts with bearing function;  replace all parts with presence of wear or damage. check that all gears do not show damage, chipping or excessive wear of teeth.