Assembly Overhaul
DISASSEMBLY
1. Remove front drive shaft by using plastic hammer.
2. Remove 8 bolts for fastening differential carrier (2 of which are reamer bolts) and then take differential assembly out of housing.
3. Set special tool on vise securely.
Special Tool
(A): 09944-76010
4. Using 4 bolt and nut sets, set differential assembly onto deferential carrier holder.
5. Put identification marks on differential side bearing caps.
6. Take off differential side bearing lock plates and differential side bearing caps removing their bolts and then take out bearing adjusters, side bearing outer races and drive bevel gear with differential case.
7. Turn differential assembly together with special tool by 90° and grip it with vise again.
Special Tool
(A): 09944-76010
8. Hold universal joint flange with special tool and then re move flange nut by using power wrench.
Special Tool
(B): 09922-66020
9. Make mating marks on drive bevel pinion and companion flange.
CAUTION: Don't make mating mark on the coupling surface of the flange.
10. Remove companion flange from pinion. Use special tool if it is hard to remove.
Special Tool
(C): 09913-65135
11. Remove bevel pinion with rear bearing, and spacer from carrier.
If it is hard to remove, screw an used nut into pinion and hammer on that nut with a plastic hammer but never directly on pinion.
12. Using special tools, pull out differential side bearings.
Special Tool
(D): 09913-85230
(E): 09913-61510
13. With aluminum plates placed on vise first, grip differential case with it and remove bevel gear by removing its 10 bolts.
14. Drive out spring pin with special tool and hammer and disassemble differential side gears, pinions, washers and shaft in differential case.
Special Tool
(F): 09922-85811
15. Remove bevel pinion rear bearing by using bearing puller and press.
16. Drive out bevel pinion bearing outer races in differential carrier by hammering metal stick applied to them.
INSPECTION
- Check companion flange for wear or damage.
- Check bearings for wear or discoloration.
- Check differential carrier for cracks.
- Check drive bevel pinion and bevel gear for wear or cracks.
- Check side gears, pinion gears and pinion shaft for wear or damage.
- Check side gear spline for wear or damage.
ADJUSTMENT AND REASSEMBLY
Judging from faulty conditions noted before disassembly and what is found through visual check of bearing and gear tooth etc. after disassembly, prepare replacing parts and proceed to reassembly according to procedures as described below.
CAUTION:
^ Bevel gear and pinion must be replaced as a set when either replacement becomes necessary.
^ When replacing taper roller bearing, replace as inner race & outer race assembly.
DIFFERENTIAL CARRIER
For press-fitting bevel pinion bearing outer races, use special tools as shown.
CAUTION: Perform press-fitting carefully so as not to tilt outer race.
Special Tool
(A): 09924-74510
(B): 09926-68310
(C): 09913-75510
DIFFERENTIAL CASE
1. Install differential side gears and side pinions with pinion shaft temporarily and measure backlash in side gear thrust direction as follows.
Side gear thrust play: 0.12 - 0.37 mm (0.005 - 0.014 inch)
Bevel gear
- Hold differential case with soft jawed vise and apply measuring tip of dial gauge to top surface of gear.
- Using 2 screwdrivers, move gear up and down and read movement of dial gauge pointer.
Special Tool
(D): 09900-20606
(E): 09900-20701
Left case
- Using similar procedure to the above, set dial gauge tip to gear shoulder.
- Move gear up and down by hand and read dial gauge.
2. If thrust play is out of specification, select suitable thrust washer from among following available size, install it and check again that specified side gear thrust play is obtained.
Available thrust washer thickness: 0.9, 1.0, 1.1, and 1.2 mm (0.035, 0.039, 0.043, and 0.047 inch)
3. Drive in spring pin for differential side pinion shaft till it is flush with differential case surface.
Special Tool
(F): 09922-85811
4. Put bevel gear on differential case and fasten them with 10 bolts by tightening them to specified torque. Use thread lock cement for 10 bolts.
CAUTION: Use of any other bolts than that specified is prohibited.
"A": Thread lock cement 99000-32020
Tightening Torque
(a): 85 Nm (8.5 kg-m, 61.5 ft. lbs.)
5. Press-fit side bearing with special tool and press.
Special Tool
(G): 09944-66020
6. Hold bearing press-fitted in step 7 with holder and press-fit side bearing on the other side.
NOTE: Be sure to use bearing holder for the purpose of protecting lower bearing.
Special Tool
(G): 09944-66020
(H): 09951-16060
DRIVE BEVEL PINION
To engage bevel pinion and gear correctly, it is prerequired to install bevel pinion to differential carrier properly by using adjusting shim as described. Shown are relative positions of bevel pinion, differential carrier and mounting dummy.
1. Install bevel pinion dummy with bearings into differential carrier and tighten flange nut so that specified bearing preload is obtained.
NOTE:
^ This installation requires universal joint flange not equipped with groove on flange periphery.
^ This installation requires no spacer or oil seal.
^ Before taking measurement with spring balance or torque wrench, check for rotation by hand and apply small amount of oil to bearings.
Special Tool
(A): 09922-75222
(B): 09926-78310
Pinion bearing preload
(a): 9.0- 17.0 kg-cm (7.8- 14.7 inch lbs.)
Starting torque: 1.8 - 3.4 kg (4.0 - 7.5 lb)
2. Set dial gauge to bevel 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, turn dummy back and force by hand a couple of times and 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): 09926-78311
(D): 09900-20606
3. Place zero-adjusted mounting dummy and dial gauge set on pinion dummy and take measurement between zero position and extended dial gauge measuring tip.
NOTE:
^ Repeat turning back and force of dummy and measure distance as far as top surface of pinion dummy accurately.
^ When dial gauge measuring tip extends from 0 (zero) position, pointer turns counterclockwise.
^ Measured value may exceed 1 mm. Therefore, it is also necessary to know reading of short pointer.
Special Tool
(C): 09926-78311 (Mounting dummy)
(D): 09900-20606 (Dial gauge)
4. Obtain adjusting shim thickness by using measured value by dial gauge (C).
94 in above equation is A + B of mounting dummy (special tool) (C).
5. Select adjusting shim(s) closest to calculated value from among following available sizes and put it in place and then press-fit rear bearing.
Special Tool
(E): 09925-18010
(F): 09940-53111
6. With new pinion spacer inserted as shown, install front bearing to differential carrier.
NOTE:
^ Make sure to use new spacer for reinstallation.
^ Apply oil to bearings.
7. Using special tool and plastic hammer drive oil seal into differential carrier 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, set preload of pinion to specification.
NOTE:
^ Before taking measurement with spring balance or torque wrench, 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. Turning back overtightened flange nuts should be avoided.
Pinion bearing preload: 9.0 - 17.0 kg-cm (7.8 - 14.7 inch lbs.)
Starting Torque: 1.8 - 3.4 kg (4.0 - 7.5 lb)
Special Tool
(A): 09922-75222
(H): 09922-66020
ASSEMBLING UNIT
1. Place bearing outer races on their respective bearings. Used left and right outer races are not interchangeable.
2. Install case assembly in carrier.
3. Install side bearing adjusters on their respective carrier, making sure adjuster are threaded properly.
4. Align match marks on cap and carrier. Screw in two side bearing cap bolts two or three turns and press down bearing cap by hand.
NOTE: If bearing cap does not fit tightly on carrier, side bearing adjuster is not threaded properly. Reinstall adjuster.
Tighten cap bolts.
Provisional Tightening Torque
(a): 15 Nm (1.5 kg-m, 11.0 ft. lbs.)
5. Tighten both bearing adjusters so as to obtain specified gear backlash and at the same time, obtain preload of side bearing.
Special Tool
(A): 09930-40120 (Attachment)
(B): 09930-40113 (Rotor holder)
Bevel gear backlash: 0.13 - 0.18 mm (0.005 - 0.007 inch)
NOTE:
^ Be sure to apply measuring tip of dial gauge at right angles to convex side of tooth.
^ Measure at least 4 points on drive bevel gear periphery.
^ As a practical measure following would be recommended to obtain specified backlash and side bearing preload at the same time.
1. Obtain specified backlash by turning both adjusters inward lightly.
2. Tighten both adjusters further by one notch at a time.
6. Measure preload of pinion with spring balance or torque wrench and check composite preload of pinion bearing and side bearing.
Special Tool
(E): 09922-75222
NOTE:
^ Standard preload is shown in graph, which should be read as follows.
Example:
When preload of bevel pinion is 2.6 kg/5.73 lb, acceptable composite preload of both pinion bearings and side bearings should be between 2.8 and 3.2 kg/6.17 and 7.05 lb.
^ Bearing preload can be checked roughly by using flange holder as shown in image. 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.
^ Repeat side bearing adjustment until gear backlash and composite bearing preload are compatible within specification, if fail to obtain specified measurements first.
Special Tool
(F): 09922-66020
7. Torque bearing cap bolts to specification and install bearing lock plates.
Tightening Torque
(a): 60 Nm (6.0 kg-m, 43.5 ft. lbs.)
(b): 12 Nm (1.2 kg-m, 9.0 ft. lbs.)
8. As final step, check gear tooth contact as follows.
1. After cleaning tooth surface of 10 bevel gears, paint them with gear marking compound evenly by using brush or sponge etc.
2. Turn gear to bring its painted part in mesh with bevel pinion and turn it back and forth by hand to repeat their contact.
3. Bring painted part up and check contact pattern, referring to 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, caulk flange nut with caulking tool and hammer.
10. Clean mating surfaces of both housing and carrier and apply sealant to housing side evenly.
"A": Sealant 99000-31110
11. With differential assembly installed in housing, position it with 2 reamer bolts and then install other 6 bolts.
12. Torque all bolts to specification.
Tightening Torque for differential carrier bolts
23 Nm (2.3 kg-m, 17.0 ft. lbs.)
13. Install front drive shaft.