Front Differential Reassembly
Front Differential ReassemblyReference: Front Differential Dismounting and Remounting: Front - H27 Engine Model
Reference: Front Differential Disassembly: Front - H27 Engine Model
Reference: Front Differential Inspection: Front - H27 Engine Model
Judging from abnormal conditions noted before disassembly and what is found through visual check of bearing and gear tooth etc. after disassembly, prepare replacing parts and start reassembly according to procedures as described below.
CAUTION:
^ Bevel gear and pinion must be replaced as a set even if either one of them has to be replaced.
^ When replacing taper roller bearing, replace as inner race & outer race assembly.
Differential Carrier
For press-fitting pinion bearing outer races, use special tools as shown in the figure.
CAUTION: Press-fit pinion bearing outer races carefully so as not to tilt outer race.
Special Tool
(A): 09924-74510
(B): 09926-68310
(C): 09913-75510
Differential Case Assembly
1. Install differential gears (3), free axle hub (4) and thrust washers (2) to differential left case (7).
2. Install differential left case to differential right case (1) and tighten screws (8).
3. Put bevel gear (1) on differential case (2) and fasten them with bevel gear bolts (3) by tightening them to specified torque. Use thread lock cement for bevel gear bolts (3).
CAUTION: Use of any other bolts than that specified is prohibited.
"A": Thread lock cement 99000-32020
Tightening torque
Drive bevel gear bolt a: 85 Nm (8.5 kg-m, 61.5 ft. lbs.)
4. Press-fit differential side bearing (1) with special tool and hydraulic press.
Special Tool
(G): 09944-66020
5. Install axle lock actuator (1) to differential case (2) temporarily.
NOTE: Note that installing direction is as shown in the figure.
6. Hold bearing press-fitted in Step 4) with holder (special tool (H)) and press-fit side bearing on the other side.
NOTE: Be sure to use bearing holder (special tool (H)) for the purpose of protecting lower bearing.
Special Tool
(G): 09944-66020
(H): 09951-16060
Drive Bevel Pinion
To engage bevel gear and pinion correctly, it is prerequired to install pinion to differential carrier properly by using adjusting shim as described below. Shown in the figure of Step 4) are relative positions of pinion, differential carrier and mounting dummy.
1. Install pinion dummy with bearings into differential carrier and tighten flange nut (1) so that specified bearing preload is obtained.
NOTE:
^ This installation requires no spacer and oil seal.
^ Before taking measurement with spring balance (2) or torque wrench (3), check for rotation by hand and apply small amount of oil to bearings.
Special Tool
(A): 09922-75222
(B): 09926-78311
(C): 09951-46010
Pinion bearing preload
(a): 0.9 - 1.7 Nm (9.0 - 17.0 kg-cm, 7.8 - 14.7 inch lbs.)
Spring measure reading
1.8 - 3.4 kg (4.0 - 7.5 lb)
2. Set dial gauge to pinion mounting dummy and make 0 (zero) adjustment on surface plate.
NOTE:
^ When setting dial gauge to mounting dummy, tighten screw lightly. Be careful not to overtighten it, which will cause damage to dial gauge.
^ With dial gauge set, roll dummy back and force by hand once or twice, and then attain accurate 0 (zero) adjustment.
^ It is desirable that short pointer indicates beyond 2 mm when long one is at 0 (zero).
Special Tool
(C): 09926-78320
(D): 09900-20607
3. Place zero-adjusted mounting dummy and dial gauge set on pinion dummy, and then take measurement between zero position and extended dial gauge measuring tip.
NOTE:
^ Roll dummy back and force by hand once or twice, and then measure distance to the top surface of pinion dummy accurately.
^ When dial gauge measuring tip extends from 0 (zero) position, pointer turns counterclockwise.
Special Tool
(B): 09926-78311
(C): 09926-78320
(D): 09900-20607
(E): 09922-76570
4. Obtain shim thickness by using measured value by dial gauge (which represents "c" in figure) in the following equation.
Special Tool
(A): 09900-20607
(B): 09926-78320
(C): 09922-75222
(D): 09926-78311
(E): 09922-76570
(F): 09951-46010
5. Select shim(s) (2) closest to calculated value and put it in place. And then, press-fit front bearing (1).
Special Tool
(E): 09913-85210
(F): 09927-66010
Available shims
1.00, 1.03, 1.09, 1.12, 1.15, 1.18, 1.21, 1.24, 1.27, 1.30 and 0.3 mm (0.039, 0.041, 0.043, 0.044, 0.045, 0.046, 0.048 0.049, 0.050, 0.051 and 0.012 inch)
6. With new pinion spacer (3) inserted as shown, install rear bearing (5) to differential carrier (4).
NOTE:
^ Make sure to use new spacer for reinstallation.
^ Apply oil to bearings.
7. Using special tool and plastic hammer, install oil seal (2) into differential carrier (1) till it becomes flush with carrier end. Then, apply grease to oil seal lip.
Special Tool
(G): 09951-18210
"A": Grease 99000-25010
8. While tightening flange nut gradually with flange holder (special tool) and power wrench (4-10 magnification) (1), set preload of pinion to specification.
NOTE:
^ Before taking measurement with spring balance (3) or torque wrench (4), check for smooth rotation by hand.
^ Bearing preload can be measured roughly by pinion rotating angle which is due to arm weight of flange holder installed in flange.
^ Be sure to tighten gradually and carefully till specified starting torque is obtained. The use of overtightened flange nuts should be avoided.
Pinion bearing preload
0.9 - 1.7 Nm (9.0 - 17.0 kg-cm, 7.8 - 14.7 inch lbs.)
Spring measure reading
1.8 - 3.4 kg (4.0 - 7.5 lb)
Special Tool
(A): 09922-75222
(H): 09922-66021
Assembling Unit
1. Apply gear oil to differential side bearing, place differential side bearing outer races on their respective bearings, and install differential case assembly in differential carrier.
2. Measure distance "a" and "b".
"a" - "b" = Right side shim(s) + Left side shim(s)
3. Select shim(s) for right and left sides and install them between differential carrier and differential bearing outer races.
NOTE: Two 2.0 mm (0.079 inch) shims for the left side and two 3.0 mm (0.118 inch) shims for the right side are installed as standard. Therefore, choose shims which are close to the ones mentioned above. For example, if "a" - "b" is 10.05 mm (0.396 inch), combination pattern is as follows.
Available shim(s)
Right side
1.75, 1.85, 1.95, 2.00, 2.05, 2.15 and 2.25 mm (0.069, 0.073, 0.077, 0.079, 0.081, 0.085 and 0.089 inch)
Left side
2.75, 2.85, 2.95, 3.00, 3.05, 3.15 and 3.25 mm (0.108, 0.112, 0.116, 0.118, 0.120, 0.124 and 0.128 inch)
4. Measure bevel gear backlash by using dial gauge. If backlash is out of range, repeat from step 3).
Drive bevel gear backlash 0.10 - 0.20 mm (0.004 - 0.008 inch)
NOTE:
^ Before measurement, hit shims lightly for several times by plastic hammer to position shims in correct position.
^ Be sure to apply measuring tip of dial gauge at right angles to convex side (drive side) of tooth.
^ Measure at least 4 points on drive bevel gear periphery.
^ If backlash is out of specification, change shim(s) so that backlash is within specification.
5. Install axle lock actuator mounting bolts.
6. Assemble differential carrier cover and differential carrier temporarily.
NOTE: Tighten 12 mm thread diameter bolts (1) first, then loosen 8 mm thread diameter bolts (2).
Tightening torque
Front differential cover bolt (12 mm) a: 85 Nm (8.5 kg-m, 61.5 ft. lbs.)
Front differential cover bolt (8 mm) b: 23 Nm (2.3 kg-m, 17.0 ft. lbs.)
7. Measure preload of pinion with spring balance (1) or torque wrench (2), and then check composite preload of pinion bearing and side bearing.
NOTE:
^ Standard preload is shown in graph, which should be read as follows.
Example:
When preload of pinion is 2.6 kg / 5.73 lb, acceptable composite preload of both pinion bearings and differential side bearings should be between 2.8 and 3.2 kg / 6.17 and 7.05 lb.
Special Tool
(D): 09922-75222
^ Bearing preload can be checked roughly by using flange holder as shown in the figure. In this measurement, holder arm itself will work as balance weight and torque will be replaced with angle. However, flange should be rotated very slowly with hand support so as not to allow over revolution due to inertia.
Special Tool
(E): 09922-66021
^ Repeat differential side bearing adjustment until gear backlash and composite bearing preload are compatible within specification.
8. As final step, check gear tooth contact as follows.
a. After cleaning tooth surface of 10 bevel gears, paint them with gear marking compound evenly by using brush (1) or sponge etc.
b. Assemble differential carrier cover and differential carrier temporarily.
NOTE: Tighten 12 mm thread diameter bolts (1) first, and then loosen 8 mm thread diameter bolts (2).
Tightening torque
Front differential cover bolt (12 mm) a: 85 Nm (8.5 kg-m, 61.5 ft. lbs.)
Front differential cover bolt (8 mm) b: 23 Nm (2.3 kg-m, 17.0 ft. lbs.)
c. Turn gear to bring its painted part in mesh with pinion and turn it back and forth by hand to repeat their contact.
d. Remove cover bolts (1, 2) and differential carrier cover.
NOTE: Loosen 8 mm thread diameter bolts (2) first, and then loosen 12 mm thread diameter bolts (1).
e. Bring painted part up and check contact pattern, referring to the following chart. If contact pattern is not normal, readjust or replace as necessary according to instruction in chart.
NOTE: Be careful not to turn bevel gear more than one full revolution, for it will hinder accurate check.
9. Upon completion of gear tooth contact check in Step 8), clean mating surfaces of both cover and carrier and apply sealant "A" to cover side evenly.
"A": Sealant 99000-31110
10. Install differential carrier cover to differential carrier.
NOTE: Tighten 12 mm thread diameter bolts (1) first, and then loosen 8 mm thread diameter bolts (2).
Tightening torque
Front differential cover bolt (12 mm) a: 85 Nm (8.5 kg-m, 61.5 ft. lbs.)
Front differential cover bolt (8 mm) b: 23 Nm (2.3 kg-m, 17.0 ft. lbs.)
11. Install axle lock actuator motor onto differential carrier cover.
"A": Grease 99000-25010
12. Install front drive shaft case (1) to differential housing (2).
"A": Sealant 99000-31110
Tightening torque
Front drive shaft case bolt a: 50 Nm (5.0 kg-m, 36.5 ft. lbs.)
13. Install front mounting bracket R (1) onto differential housing (2).
"A": Sealant 99000-31110
Tightening torque
Front mounting bracket bolt a: 50 Nm (5.0 kg-m, 36.5 ft. lbs.)