2720C11 REAR DIFFERENTIAL UNIT - OVERHAUL WITH THE DIFFERENTIAL DETACHED (SUV) - Fiat - PANDA - eLearn

169001654 - 2720C11 REAR DIFFERENTIAL UNIT - OVERHAUL WITH THE DIFFERENTIAL DETACHED (SUV)

) Place the rear differential assembly in a vice.1. Fit tools (1a) and unscrew the viscous coupling nut (1b).

	Description	Code	Function
1a	Counter-torque	1.871.006.000	Joint retainer

1. Withdraw the viscous coupling and remove.

Remove the bevel pinion oil seal.1. Unscrew the retaining collar (1a) using lever (1b) and countertorque brace (1c).

	Description	Code	Function
1b	Spanner	1.871.005.400	Loosen/tighten collar

	Description	Code	Function
1c	Reaction bush	1.871.005.100	Reaction

Remove the tools fitted previously to remove the viscous coupling.

	Description	Code	Function
-	Counter-torque	1.871.006.000	Joint retainer

1. Prise up and remove the differential joints.Remove the joint oil seals.2. Unscrew the bolts fixing the cover.Use an appropriate tool to cut the cover sealing strip.

	Description	Code	Function
-	Blade	1.870.718.000	Cut the sealant strip

3. Remove the rear differential cover.

Mark the original lh and rh position of the mounting brackets before removal.

1. Undo the fixing bolts (1a) and remove the mounting bracket (1b).

Take the GREATEST care during the operation described below.

1. Position the tool (1a) in its seat on the differential casing (1b) as shown in the figure and adjust the settings to bring about a slight deformation sufficient to allow removal/fitting of the rear differential unit.

	Description	Code	Function
1a	Divider	1.871.006.300	Rear differential case divider

Mark the original position of the spacers before removal.

2. Remove the rear differential unit from its seat with taper bearing outer races.

- Remove the tool fitted previously.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

1. Manually remove the bevel pinion (1a) from its seat in the differential casing (1b) and recover the spacer (1c).

Position the bevel pinion in the press.1. Position tool (1a) and (1b) on the bevel pinion (1c) and remove the tapered bearing inner race (1d) and thrust washer (1e) in the press.

	Description	Code	Function
1a	Reaction plate	1.870.845.000	Reaction plate

	Description	Code	Function
1b	Extractor	1.871.006.100	Bearing extractor

1. Remove the bevel pinion (1a) and oil seal (1b) from the differential casing using tool (1c).

	Description	Code	Function
1c	Extractor	1.871.004.500	Bearing extractor

1. Use an extractor (1a) and remove the tapered bearing outer race (1b) in the press.

1. Position tool (1a) and (1b) on the differential unit (1c) and remove the tapered bearing inner race (1d) in the press.

	Description	Code	Function
1a	Reaction plate	1.870.845.000	Reaction plate

	Description	Code	Function
1b	Reaction plate	1.870.845.000	Reaction plate

1. Position tool (1a) and (1b) on the differential unit (1c) and remove the tapered bearing inner race (1d) in the press.

	Description	Code	Function
1a	Reaction plate	1.870.845.000	Reaction plate

	Description	Code	Function
1b	Reaction plate	1.870.845.000	Reaction plate

Refitting ( Removing

) 1. Position the differential unit (1a) in the press and fit the taper bearing inner race (1b) using the fitting tool (1c).

	Description	Code	Function
1c	Fitting tool	1.871.004.400	Fitting tapered bearings

1. Position the differential unit (1a) in the press and fit the taper bearing inner race (1b) using the fitting tool (1c).

	Description	Code	Function
1c	Fitting tool	1.870.424.000	Fitting tapered bearings

1. Position the differential housing (1a) in the press and fit the bearing outer race (1b) using the fitting tool (1c).

	Description	Code	Function
1c	Fitting tool	1.870.424.000	Fitting bearing races

1. Position the differential housing (1a) in the press and fit the bearing outer race (1b) using the fitting tool (1c).

	Description	Code	Function
1c	Fitting tool	1.871.005.800	Fitting bearing races

1. Fit the taper bearing inner race (1a) for the pinion and the dummy pinion (1b) in the differential housing.

	Description	Code	Function
1b	Dummy pinion	1.871.005.000	Template

1. Fit the spacer removed PREVIOUSLY on the bevel dummy pinion.

1. Fit the taper bearing inner race on the dummy bevel pinion.

Tighten the ring nut fixing the dummy bevel pinion manually until it is in contact.1. Fit the bevel dummy pinion gauge in the differential housing inserting it from the side opposite the oil drain plug.

	Description	Code	Function
1	Dummy pinion gauge	1.871.004.900	Template

1. Fit the reaction bracket (1a) and tighten the fixing bolt (1b), positioning it from inside the gauge.

1. Fit the retaining U-bolt (1a) in place and tighten the fixing bolts (1b) so that they are in contact.

1. Using a feeler gauge, measure the distance between the bevel dummy pinion plane and the dummy ring gear.

1. The stamp (A) corresponds to the identification number for the differential ring gear; the same number is also on the bevel pinion shaft because the two components must be matched. If one of the two components has to be replaced then the other one with the same number also has to be replaced. The stamp (B) on the pinion shaft indicates the VP value.

After the measurement has been taken, determine the size of the scraper ring for the bevel pinion using the following formula.S = [X + (± VP)] ± 0,04S = thickness of scraper ring (mm)X = value measured using feeler gauge (mm)VP = value shown on pinion0.04 = tolerance (mm)

The value VP can be either positive or negative.The spacers available vary from a minimum of 0.51 mm to a maximum of 1.40 mm in increments of 0.05 mm.

Example of numerical calculation with positive VP.Let us suppose that the following figures have been obtained:X = 1.15 mm (feeler gauge reading)VP = + 2 = 0,02 mmS = (1,15 + 0,02) ± 0,04 mm = 1,13 ÷ 1,21Example of numerical calculation with negative VP.Let us suppose that the following figures have been obtained:X = 1.15 mm (feeler gauge reading)VP = -2 = -0.02 mmS = (1,15 -0.02) ± 0,04 mm = 1.09 ÷ 1.17Tighten the ring nut fixing the bevel pinion.Undo the bolt fixing the dummy bevel pinion gauge.Undo the two bolts fixing the U-bolt retaining the dummy bevel pinion gauge.Remove the dummy bevel pinion gauge.

	Description	Code	Function
-	Dummy pinion gauge	1.871.004.900	Template

Remove the dummy bevel pinion with the two conical bearings and the USED spacer.

	Description	Code	Function
-	Dummy pinion	1.871.005.000	Template

Take the GREATEST care during the operation described below.

Position the toolin its seat on the differential casing as illustrated previously and adjust the settings to bring about a slight deformation sufficient to allow removal/fitting of the rear differential unit.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

1. Fit the differential unit (1a) and the two bearings (1b) and the two left and right spacers (1c) marked previously in the differential housing.

- Remove the tool fitted previously.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

1. Fit the left and right retaining U-bolts (1a) marked previously for the differential unit in place and tighten the fixing bolts (1b).

1. Position the tool in the differential unit until the concave part of the actual tool and the satellite shaft match completely.

1. Fit the special tool and measuring the rolling torque for the differential unit to determine the total thickness of the two spacers.

To determine the total size of the two spacers it is advisable to start the check using the old spacers and, if necessary, increasing or decreasing the size to produce the correct rolling torque. The shims available go from a minimum of 1.91mm to a maximum of 3.00 mm.

	Subject	Value
-	Differential unit rolling torque (daNm)	0.83 -3,32
-	Differential unit rolling torque (Ncm)	83 - 332

	Description	Code	Function
1	Counter-torque	1.870.789.000	Counter-torque

Take the GREATEST care during the operation described below.

1. Position the toolin its seat on the differential casing as illustrated previously and adjust the settings to bring about a slight deformation sufficient to allow removal/fitting of the rear differential unit.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

2. Remove the rear differential unit from its seat with taper bearing outer races and spacers.

- Remove the tool fitted previously.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

1. Fit the scraper ring (1b) that has been correctly defined and the taper bearing (1c) on the bevel pinion (1a) in the press using the special fitting tool (1d).

	Description	Code	Function
1d	Fitting tool	1.871.004.500	Bearing fitting tool

1. Fit the bevel pinion complete with bearing inner race and scraper ring in place in the differential housing.

1. Fit the NEW space ring for the taper bearing inner race (1b) on the bevel pinion.

1. Tighten the ring nut fixing the bevel pinion.

1. Tighten the ring nut fixing the bevel pinion to torque using the special lever (1a) and counter-torque tool (1b).

	Value daNm	Fastening	Component	Ø
-	20	Ring nut	Bevel pinion	-

	Description	Code	Function
1a	Spanner	1.871.005.400	Loosen/tighten collar

	Description	Code	Function
1b	Reaction bush	1.871.005.100	Reaction

Remove the lever and counter-torque tool.

	Description	Code	Function
-	Spanner	1.871.005.400	Loosen/tighten collar

	Description	Code	Function
-	Reaction bush	1.871.005.100	Reaction

1. Fit the counter-torque tool (1a) and measure the bevel pinion rolling torque using the special tool (1b).

	Description	Code	Function
1a	Reaction bush	1.871.005.100	Reaction

	Description	Code	Function
1b	Counter-torque	1.870.789.000	Counter-torque

Alternate a gradual closing stage for the ring nut fixing the bevel pinion with a check on the rolling torque until the value indicated is reached.

	Subject	Value
-	Bevel pinion rolling torque (Nm)	2,3 - 3,4
-	Bevel pinion rolling torque (Nm)	230 - 340

If the value indicated is exceeded, the spacer fitted on the bevel pinion has to be REPLACED once again and the tightening procedure repeated again.

Take the GREATEST care during the operation described below.

	Description	Code	Function
-	Divider	1.871.006.300	Rear differential case divider

1. Fit the differential unit (1a) and the two bearings (1b) and the two spacers (1c).

- Remove the tool fitted previously.

	Description	Code	Function
-	Divider	11.871.006.300	Rear differential case divider

The U-bolts retaining the differential unit should be removed ensuring that they are correctly positioned.

1. Fit the left and right retaining U-bolts (1a) marked previously for the differential unit in place and tighten the fixing bolts (1b).

	Value daNm	Fastening	Component	Ø
1b	4.1 - 6.1	Bolt	-	-

1. Position the differential assembly on a test bench.2. Fit the special lever (2a) and counter-torque tool (2b) in place on the bevel pinion to prevent rotation.

	Description	Code	Function
2a	Spanner	1.871.005.400	Loosen/tighten collar

	Description	Code	Function
2b	Reaction bush	1.871.005.100	Reaction

3. Using the special dial gauge (3a) carry out the measurement on the ring gear at the point indicated (3b), moving the ring gear by hand, measure the clearance between it and the bevel pinion making sure that the value measured corresponds to the figures given.

	Description	Code	Function
3a	Dial gauge	1.871.005.300	Measuring clearance

	Subject	Value
-	Clearance between ring gear and bevel pinion (mm)	0.10 - 0.18

If the value measured was below the nominal figure, increase the size of the shim on side X and decrease the size of the shim on side Y by the same value as it was increased on side X. If the value measured was above the nominal figure, increase the size of the shim on side Y and decrease the size of the shim on side X by the same value as it was increased on side Y. The total thickness of the two shims should not vary from the figure set previously.

If the value measured for the clearance between the bevel pinion and the ring gear differs from the figures given, the distribution of the differential shims must be checked again.- Remove the tools fitted previously.

	Description	Code	Function
-	Spanner	1.871.005.100	Reaction

	Description	Code	Function
-	Reaction bush	1.871.005.400	Loosen/tighten collar

Refit the differential casing rear cover renewing the bead of sealant and tighten the fixing bolts to torque.

	Description	Qty.	Component	Type	Classification
-	Rubber Wacker	-	-	T209	Sealant

	Value daNm	Fastening	Component	Ø
-	3.8 - 4.5	Bolt	-	-

Fit the bevel pinion rear oil seal using the special fitting tool.

	Description	Code	Function
-	Fitting tool	1.871.006.200	Oil seal fitting tool

Fit the oil seals for the differential joints using the special fitting tool.

	Description	Code	Function
-	Fitting tool	1.871.005.900	Oil seal fitting tool

Fit the two differential joints in position.Place the rear differential assembly in a vice.Position the viscous joint on the bevel pinion.Fit the tools and tighten the nut fixing the viscous coupling to torque.

	Description	Code	Function
-	Counter-torque	1.871.006.000	Joint retainer

	Value daNm	Fastening	Component	Ø
-	12 - 15	Nut	-	-

Remove the tools fitted previously to fit the viscous coupling.

	Description	Code	Function
-	Counter-torque	1.871.006.000	Joint retainer