Differential Assembly: Service and Repair
Fig. 1 Typical differential carrier:
DISASSEMBLY
1. Remove side retainers, Fig. 1.
2. Remove differential case from carrier.
3. When replacing side bearing, extract bearing outer race from side retainer.
4. Loosen drive pinion nut, holding companion flange and pull off companion flange using a suitable puller.
5. Press drive pinion from carrier using a press. Remove drive pinion with rear bearing cone, bearing spacer and adjusting washers.
6. Remove oil seal.
7. Remove pinion bearing with pinion bearing spacer and front bearing cone.
8. Press rear bearing inner race from drive pinion.
9. Drive out front and rear bearing outer races and remove bearing.
10. Remove ring gear.
11. Remove pinion mate shaft lock pin from ring gear side. Lock pin is caulked at pin hole mouth on differential case.
12. Remove pinion mate shaft and the pinion mate gears, side gears and thrust washers.
INSPECTION
Thoroughly clean all disassembled parts, and examine them to see that they are worn, damaged or otherwise faulty, and how they are affected. Repair or replace all faulty parts, whichever is necessary.
1. Check gear teeth for scoring, cracking or chipping, and make sure that tooth contact pattern indicates correct meshing depth. If any fault is evident, replace parts as required. Drive pinion and drive gear are supplied as a set; therefore, should either part be damaged, replace as a set.
2. Check pinion gear shaft, and pinion gear for scores and signs of wear, and replace as required. Follow the same procedure for side gear and their seats on differential case.
3. Inspect all bearing races and rollers for scoring, chipping or evidence of excessive wear.
Fig. 4 Measuring Pinion To Side Gear Backlash:
4. Inspect thrust washer faces. Small faults can be corrected with sandpaper. Inspect pinion mate-to-side gear backlash, Fig. 2. If clearance between side gear and thrust washer exceeds .0039-.0079 inch�MDBO/MDNM (less than .0059 inch on models), replace thrust washers.
5. Inspect carrier and differential case for cracks or distortion. If either condition is evident, replace faulty parts.
ASSEMBLY
Reverse ``Disassembly'' procedure to assemble and note the following:
GEAR CASE ASSEMBLY
1. Assemble pinion mates, side gears and thrust washers in differential case.
2. Install pinion shaft to differential case.
3. Adjust side gear-to-pinion mate backlash by selecting side gear thrust washers. Backlash should be .0039-.0079 inch (less than .0059 inch on models).
4. Lock pinion shaft lock pin using a punch after secured into place.
5. Apply oil to gear tooth surfaces and thrust surfaces and check if they turn properly.
6. Place ring gear on differential case and torque bolts to 65-72 ft. lbs.
7. On 1982-84 Maxima, press side bearing cone onto differential case.
DRIVE PINION PRELOAD
Adjust preload of drive pinion with spacer and washer between front and rear bearing cones, regardless of thickness of pinion height adjusting washer. This adjustment must be performed without oil seal inserted.
1. Press front and rear bearing outer races into gear carrier.
Fig. 3 Pinion height & preload adjusting tools:
2. Insert pinion height adjusting washer of .1217 inch thickness and rear bearing cone into Dummy Shaft ST31212000 to make convenient to adjust pinion height, Fig. 3.
Fig. 4 Torquing pinion nut:
Fig. 5 Measuring pinion preload:
3. Install drive pinion bearing spacer, washer, front bearing cone, Drive Pinion Dummy Collar ST31214000 and companion flange on dummy shaft and tighten drive pinion nut using Stopper ST31852000, Fig. 4. Measure pinion bearing preload using Preload Gauge ST3127S000, and select washer and spacer that will provide required preload, Fig. 5.
Fig. 6 Measuring drive pinion height:
DRIVE PINION HEIGHT
On 1982-84 Maxima, perform steps 1 through 3.
Adjust pinion height with washer provided between rear bearing cone and back of pinion gear.
1. Install height gauge ST31211000 on carrier with dummy shaft mounted, Fig. 6.
2. Measure the clearance (N) between the tip end of height gauge and the end surface of dummy shaft, using a thickness gauge, Fig. 6.
3. The thickness of drive pinion height adjusting washer can be obtained from the following formula: T= W + N - ((H - D' - S) 0.01 - 0.20 where T = required thickness of rear bearing adjusting washers in millimeters, W = thickness of washers temporarily inserted in millimeters, N = measured value with thickness gauge in millimeters, H = figure marked on the drive pinion head, D' = figure marked on the dummy shaft, S = figure marked on the height gauge and figures for H, D' and S are dimensional variations in a unit 1/100 mm against each standard measurement. If values signifying H, D' and S are not given, regard them as zero and compute.
4. Install determined pinion height adjusting washer in drive pinion, and press rear bearing cone in, using Base ST30901000.
5. Lubricate pinion front and rear bearings. Install drive pinion in gear carrier and the drive pinion bearing spacer and washer, front bearing cone and front bearing pilot spacer, pilot bearing and the front oil seal.
6. Install companion flange on drive pinion and torque nut to 123-145 ft. lbs.
SIDE BEARING RETAINER SHIMS
Fig. 7 Side bearing retainer shim thickness:
Fig. 12 Location Of ``A'' & ``B'' Values:
Fig. 13 Location Of ``C'' & ``D'' Values:
Fig. 14 Location Of ``G1'' & ``G2'' Values:
1. If the hypoid gear set, carrier, differential case, side bearing or side bearing retainer has been replaced with a new part, adjust the side bearing preload with adjusting shim. The required thickness of the right and left retainer shims can be obtained from the following formulas: T1= (A + C + G1 - D) 0.01 + 0.76 - E; T2= (B + D + G2) 0.01 + 0.76 - F; where, T1 = required thickness of left side retainer shim in millimeters, Fig. 7, T2 = required thickness of right side retainer shim in millimeters, Fig. 7, A & B = figures marked on the gear carrier, Fig. 8, C & D = figures marked on the differential case, Fig. 9, E & F = differences in width of left or right side bearing against the standard width (20 mm) in millimeters, Fig. 10 (measure bearing width using master gauge KV38101900 and weight block ST32501000), G1 & G2 = figure marked on the left or right side retainer and figures for A, B, C, D, G1 and G2 are dimensional variations in a unit of 1/100 mm against each standard measurement. If values signifying A, B, C, D, G1 and G2 are not given, regard value as zero and compute.
DIFFERENTIAL CARRIER
1. Press front and rear bearing outer races into case.
2. Install selected pinion height adjusting washer in drive pinion, bevel side toward gear, and press in rear bearing inner race.
3. Lubricate front bearing with gear oil and install in gear carrier.
4. Carefully install new oil seal into carrier, ensuring that seal is flush with end of carrier, then apply suitable lubricant into cavity between lips.
5. Place drive pinion bearing adjusting spacer, then washer, on drive pinion, then lubricate rear bearing with gear oil and install drive pinion in gear carrier.
6. Hold companion flange with suitable tool and temporarily tighten pinion nut until there is no axial play. Ensure that threaded portion of drive pinion and pinion nut are free from oil and grease.
7. Tighten pinion nut by degrees until drive pinion bearing preload is 7.8-14.8 inch lbs. If torque of drive pinion nut is not 123-145 ft. lbs. when preload is within specifications, adjusting spacer must be changed.
8. Press side bearing outer race into side retainer.
Fig. 12 Side retainer installation:
9. Install selected side retainer adjusting shims and O-rings in side retainers, then install retainers in carrier with arrow marks on retainers properly positioned, Fig. 12.