4450A40 REAR WHEEL GEOMETRY - CHECK USING OPTICAL EQUIPMENT, INCLUDES ADJUSTMENT IF NECESSARY - Fiat - CROMA - eLearn

194002357 - 4450A40 REAR WHEEL GEOMETRY - CHECK USING OPTICAL EQUIPMENT, INCLUDES ADJUSTMENT IF NECESSARY

- This check procedure must be carried out after each operation on the front suspension mechanical components since its purpose is to define the position of the wheel in relation to the body (e.g.: wishbones, stub axles, shock absorbers, springs etc.).OPERATING CYCLEIntroduction- Wheel geometry/angle checks must be carried out using appropriate optical equipment after checking and adjusting tyre inflation pressure to the specified values and ensuring that the vehicle respects one of the following load conditions:- “Standard 0” - all engine fluids and approx. 8 litres of fuel in the tank- “Standard A” - vehicle unladen including spare wheel, tools, accessories and consumables, full tank of fuel..Note in the event of operations on the rear suspension wishboneTighten the tie-rods (3 transverse and 1 longitudinal) with the vehicle geometry accurately set (to avoid torsional loads on the flexible bushes). To obtain the above conditions, ballast the vehicle until dimensions C and D indicated in the figure are within the values indicated below, then tighten to torque.

Ground clearance for tightening fastenings with flexible bushes on rear suspension
Height C	207 ± 5	mm
Height D	207 ± 5	mm

CHECKING AND ADJUSTING REAR SUSPENSION GEOMETRY/ANGLESChecking geometry- Before checking rear wheel geometry, ensure that the ground clearances A and B indicated in the figure are within the specified values.

Ground clearance for checking rear geometry (Standard 0)
Height C	245 ± 5	mm
Height D	245 ± 5	mm

Ground clearance for checking rear geometry (Standard A)
Height C	237 ± 5	mm
Height D	237 ÷ 5	mm

Checking rear toe-in- Check that the rear wheel toe-in is within required limits.

REAR WHEEL TOE-IN
Standard 0	0 ÷ 2.4	mm

REAR WHEEL TOE-IN
Standard A	0.3 ÷ 2.7	mm

It is permissible for rear toe-in not to be distributed equally between the left and right sides.

- If the rear wheel toe-in is not within the recommended figures, adjust it following the instructions given below.Checking rear camber- Check that the rear wheel camber is within required limits.

REAR WHEEL CAMBER
Standard 0	-1° 20’ ± 30’	-

REAR WHEEL CAMBER
Standard A	-1° 30’ ± 30’	-

- If the rear wheel camber is not within the recommended figures, adjust it following the instructions given below.Adjusting camber and toe-in1. Position the spring retaining/compression tool (USAG 447 or similar tool) on the left spring to hold it in position during subsequent operations.

- Release the exhaust pipe from the flexible mounts to allow removal of the bolt securing the rear wishbone to the rear suspension crossmember.1. Unscrew nut (1a) on cam (1b) located on the left side securing the rear suspension rear wishbones to the crossmember.2. Fit a pin (2a) with diameter similar to bolt (2b). Extrude bolt (2b) and simultaneously insert pin (2a).

This operation is absolutely necessary to prevent the wishbone from emerging from its seat on the rear crossmember and the correct installation position being lost.

1. Proceed as before to fit a new bolt (1a) and extrude pin (1b).- Screw in a new nut without tightening to torque.

The bolt and nut must be replaced whenever an operation is carried out.

Replace the bolts only using the above procedure. Otherwise the wishbone could twist out of its seat and injure the operator.

- Remove the spring compression tool fitted previously on the left side and fit on the right spring. Then proceed as described previously to replace the right bolt securing the rear suspension rear wishbone to the crossmember.1. Adjust the screws on the bolts replaced previously to adjust the rear wheel camber to half the specified value.

The camber is altered again during toe-in adjustment due to the supplementary arm geometry.

- Screw in the bolts without tightening them.

1. Undo the bolts fixing the rear suspension front track control arm to the crossmember.- Refit new bolts (screws and nuts) and adjust the screws to ensure the rear wheel toe-in value is correct.

The bolt and nut must be replaced whenever an operation is carried out.

It is permissible for rear toe-in not to be distributed equally between the left and right sides.

- Tighten the bolts securing the rear suspension front wishbones to the crossmember to the specified torque.

Component	Fastening	dia	Value (daNm)	Validity
Rear suspension front track control arm	Bolt (to be replaced)	M12	(crossmember side) 8.1 - 9.9 + 60°

1. Adjust the bolts securing the rear suspension rear wishbone to the crossmember to restore the camber to the specified value.- Tighten the bolts securing the rear suspension rear wishbones to the crossmember to the specified torque.

Component	Fastening	dia	Value (daNm)	Validity
Rear suspension rear track control arm	Bolt (to be replaced)	M12	(crossmember side) 8.1 - 9.9 + 60°