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 control procedure should always be carried out after any operation to the front suspension mechanical components that has the function of defining the position of the wheels in relation to the bodyshell (e.g.: track control arms, steering knuckles, shock absorbers, springs, etc.).OPERATING CYCLEIntroduction- The checks on the wheel geometry/angles should be carried out, using the special equipment, after having checked and adjusted the tyre inflation pressure to the recommended values and making sure that the vehicle is one of the following load conditions:- "Standard 0" - all engine fluids and around 8 litres of fuel in the tank- "Standard A" - unladen vehicle including spare wheel, tools, accessories and supplies with a full fuel tank.Premise in the case of an operation on the rear suspension track control armsThe tightening of the track control arms (3 transverse and 1 longitudinal) should be carried out with the vehicle in precise geometry conditions (to prevent torsional loads to the flexible bushes); to produce the above conditions, apply ballast to the vehicle so that distances C and D shown in the diagram are within the values given below, then proceed with the torque tightening.

Height from the ground 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/ANGLESGeometry check- Before proceeding with the rear wheel geometry checks, make sure that the distances from the ground C and D in the diagram are within the recommended values.

Height from the ground for rear geometry check (Standard 0)
Height C	247 ± 5	mm
Height D	246 ± 5	mm

Height from the ground for rear geometry check (Standard A)
Height C	238 ± 5	mm
Height D	238 ÷ 5	mm

Rear toe in check- 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

The rear toe in does not have to be equally distributed 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.Rear camber check- 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.Adjustment of camber and toe in1. Position the spring retaining/compression tool (USAG 447 type or similar tool) by the left spring to keep it in position during the subsequent operations.

- Release the exhaust pipe from the flexible mountings to allow the extraction of the bolt securing the rear track control arm to the rear suspension crossmember.1. Undo the nut (1a) on the cam (1b) on the left side securing the rear suspension rear track control arms to the crossmember.2. Introduce a pin (2a) that has the same diameter as the fixing bolt (2b); extract the bolt (2b) and, at the same time, insert the pin (2a).

This operation is absolutely vital to prevent the track control arm from coming out of the housing on the rear crossmember with the correct fitting position being lost.

1. Working as previously, fit a new bolt (1a) and extract the pin (1b).- Screw in a new nut without tightening it to torque.

The nut and the bolt must be replaced each time.

The bolts must be replaced following the procedure described above. If this is not the case, the rotation of the track control arm with it coming out of its housing could cause damage to the operator.

- Remove the spring compression tool fitted previously on the left side and fit it on the spring on the right side, then proceed as described previously with replcing the right bolt securing the rear suspension rear track control arm to the crossmember.1. Working on the bolts replaced previously, adjust the rear wheel camber to half the recommended value.

During the adjustment of the toe in the camber should be modified once again as a result of the geometry of the additional arm.

- Screw in the bolts without tightening them.

1. Undo the bolts fixing the rear suspension front track control arms to the crossmember.- Refit new bolts (nuts and bolts) and adjust the rear wheel toe in to the recommended value using the bolts.

The nut and the bolt must be replaced each time.

The rear toe in does not have to be equally distributed between the left and right sides.

- Tighten the bolts securing the rear suspension front track control arms 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 track control arms to the crossmember until the camber value is correct.- Tighten the bolts securing the rear suspension rear track control arms 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°