1991 MAZDA MIATA Factory Service Manual

CARRIER PINION THRUST WASHER SPECIFICATIONS
Fig. 10: Measuring Carrier Gear Backlash

Courtesy of MAZDA MOTORS CORP.
LIMITED SLIP DIFFERENTIAL (RX7)
1. Check friction plate, disc and thrust washer thicknesses. See RX7 DIFFERENTIAL
SPECIFICATIONS . Measure and record thickness of 6 plate springs.
2. Measure thickness of complete clutch pack excluding conical springs. See Fig. 9
. Subtract conical spring
thickness and complete clutch pack thickness from 3.583" (91.00 mm). Difference should be .004-
010" (.10-.25 mm).
3. If clearance is excessive, use oversize friction discs. Oversize friction disc thickness is .0827" (2.10 mm).
Measure thickness of side gears, pressure rings, spider, pinion gears and thrust washers in place. See Fig.
9 .
Identifying MarkThickness In. (mm)
0.0787 (2.00)
05.0807 (2.05)
1.0827 (2.10)
15.0846 (2.15)
2.0866 (2.20)

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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Sunday, July 05, 2009 2:17:01 PMPage 15 © 2005 Mitchell Repair Information Company, LLC.

4. Subtract thickness from 3.701" (94.00 mm). Difference should be .004-.016" (.10-.40 mm). If clearance is
not as specified, install oversize thrust washers. See RX7 DIFFERENTIAL SPECIFICATIONS
.
5. Install parts in proper order. See Fig. 8
. Before installing thrust washers, coat with grease. When
installing conical springs, ensure concave side faces side gears. Align differential case and cover
alignment marks. Apply locking compound to rear face of ring gear. Install ring gear and tighten ring gear
retaining bolts to 51-61 ft. lbs. (69-83 N.m).
RX7 DIFFERENTIAL SPECIFICATIONS (LIMITED SLIP)
Pinion Assembly (B2200, B2600i, Miata, Protege 4WD & 929)
1. Using a press, install pinion bearing races in differential housing. Place original spacer, rear bearing and
Bearing Collar (49 H027 001 ) onto Drive Pinion (49 8531 565 ). Secure collar with "O" ring. Install
assembly into differential housing.
2. Install front bearing, Collar (49 8531 567 on 929 or 49 U027 001 on B2200 and B2600i), companion
flange, washer and original drive pinion nut. See Fig. 11
. Tighten flange nut so assembly can be turned
by hand.
3. Place a dial indicator on Pinion Height Gauge (49 0727 570 ). Place pinion height gauge on a flat surface
and zero dial indicator. Position Gauge Block on top of Drive Pinion (49 F027 001 ). See GAUGE
BLOCK SELECTION .
GAUGE BLOCK SELECTION
ApplicationIn. (mm)
Friction Disc Thickness
Standard.079 (2.0)
Limit.075 (1.9)
Friction Plate
Standard.079 (2.0)
Limit.075 (1.9)
Oversize.083 (2.1)
Thrust Washer
Standard.063 (1.6)
Limit.055 (1.4)
Oversize.071 (1.8)
ApplicationUse Gauge Block No.
Front Differential
B2600i
& MPV
4WD49 0305 555
Rear Differential
B220049 0305 555
B2600i,
Protege 49 0660 555

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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4. Set pinion height gauge on top of gauge block. Set dial indicator to measure distance to a point where
side bearing sits. Measure lowest point. See Fig. 11
. Measure both sides. Add both measurements
together and divide sum by 2.
5. If measurement is not zero, replace pinion spacer. Spacers are available in a range of .1213-
.1366" (3.081-3.470 mm), in .001" (.03 mm) increments. Remove dummy pinion shaft. Press rear pinion
bearing on pinion shaft.
6. Install pinion shaft, spacer, front bearing, collapsible spacer and companion flange in differential housing.
DO NOT install pinion seal at this time. DO NOT exceed one ton force or collapsible spacer will be
damaged.
7. Temporarily tighten drive pinion nut. Turn companion flange by hand to seat bearing. Tighten drive
pinion nut to 94-130 ft. lbs. (128-177 N.m). Check pinion bearing preload, at drive pinion nut. See
PINION PRELOAD SPECIFICATIONS
. If pinion bearing preload is not as specified, replace
collapsible spacer and recheck preload.
8. Remove drive pinion nut and companion flange. Install pinion seal. Apply oil to seal lip. Install
companion flange. Using a new drive pinion nut, tighten nut to 94-130 ft. lbs. (128-177 N.m). Recheck
pinion bearing preload.
PINION PRELOAD SPECIFICATIONS
4WD &
929
Miata49 N027 001
ApplicationINCH lbs. (N.m)
B2200 & 92911.3-15.6 (1.3-1.8)
B2600i 4WD
Front11.3-15.6 (1.3-1.8)
Rear7.8-12.2 (0.9-1.4)
Miata & Protege 4WD (Rear)2.6-6.1 (0.3-0.7)
MPV 4WD
Front7.8-12.2 (0.9-1.4)
Rear11.3-15.6 (1.3-1.8)
RX7
Non-Turbo7.8-12.1 (0.9-1.4)
Turbo11.3-15.6 (1.3-1.8)

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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Sunday, July 05, 2009 2:17:01 PMPage 18 © 2005 Mitchell Repair Information Company, LLC.

Fig. 11: Checking Pinion Installation & Position
Courtesy of MAZDA MOTORS CORP.
Pinion Assembly (RX7)
1. Using a press, install rear pinion bearing outer race in differential housing. Install center bearing outer
race. Using original rear bearing spacer, install rear bearing on Setting Pinion (49 F027 001 ).
2. Position drive pinion in carrier and install center bearing, long collar and companion flange. Tighten
pinion nut just enough so pinion can be turned by hand.
3. Place a dial indicator on Pinion Height Gauge (49 0727 570 ). Place pinion height gauge on a flat surface
and zero dial indicator. Position Gauge Block (49 0305 555 ) on top of Setting Pinion (49 F027 001 ).
4. Set pinion height gauge on top of gauge block. Set dial indicator to measure distance to lowest point
where side bearing sits. See Fig. 11
. Measure both sides. Add both measurements together and divide
sum by 2.
5. If measurement is not zero, replace pinion spacer. Spacers are available in a range of .1213-
.1366" (3.081-3.470 mm) in .001" (.03 mm) increments. Remove setting pinion, select spacer and press
rear pinion bearing on drive pinion shaft.
6. Install drive pinion, spacer, front bearing, collapsible spacer and companion flange in differential
housing. DO NOT install pinion seal yet. Press center bearing onto drive pinion using Adapter (49 1243
465A ). DO NOT exceed one-ton force or collapsible spacer will be damaged. Two different collapsible
spacers are available, ensure correct one is used.
RX7 DRIVE PINION COLLAPSIBLE SPACERS
7. Lubricate ends of long collar with grease and install. Using a press, install front bearing using Adapter
(49 F027 009 ). Press fit with a 2-3 ton force. DO NOT install oil seal yet. Install companion flange and
nut. Tighten drive pinion nut to 94 ft. lbs. (128 N.m). Turn companion flange by hand to seat bearing.
8. Pinion bearing preload at drive pinion nut should be 11.3-15.6 INCH lbs. (1.3-1.8 N.m). Adjust preload
by tightening drive pinion nut. If correct preload cannot be obtained within drive pinion nut tightening
range of 94-210 ft. lbs. (128-284 N.m), replace collapsible spacer and recheck preload.
9. Remove drive pinion nut and companion flange. Install pinion seal. Apply oil to seal lip. Install
companion flange. Using a new drive pinion nut, tighten nut to specification established for correct
preload.
Carrier Assembly (All Models)
1. Position differential assembly into differential housing. Install side bearing adjusters. Position side
bearing caps. Align marks made during disassembly. Install side bearing cap bolts. DO NOT tighten yet.
2. Tighten side bearing adjusters equally until adjuster contact bearing races. Mark ring gear in 4 locations,
90 degrees apart. Position a dial indicator against ring gear to check ring gear backlash.
3. Check backlash at all 4 locations. Ti
ghten side bearing adjusters equally until backlash is .0035-
ApplicationLength In. (mm)
Non-Turbo1.923-1.935 (48.85-49.15)
Turbo2.238-2.250 (56.85-57.15)

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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Sunday, July 05, 2009 2:17:01 PMPage 19 © 2005 Mitchell Repair Information Company, LLC.

.0043" (.09-.11 mm). Minimum backlash at any point is .002" (.05 mm). Difference between minimum
and maximum backlash at 4 measuring points should not exceed .0028" (.07 mm).
4. To set differential bearing preload, tighten adjustment screws equally until distance between measuring
points on carrier bearing caps is within specification. See Fig. 12
and DIFFERENTIAL CARRIER
DIMENSIONS .
5. Ensure backlash did not change when preload was set. Tighten side bearing cap bolts. Check ring gear
tooth patterns. See GEAR TOOTH CONTACT PATTERNS
article in the GENERAL
INFORMATION section.
DIFFERENTIAL CARRIER DIMENSIONS
(1)
DIFFERENTIAL LUBRICATION SPECIFICATIONS
(1)
ApplicationIn. (mm)
B2200 & B2600i
"M" Differential7.300-7.303 (185.43-185.50)
"P" Differential8.048-8.051 (204.43-204.50)
Miata5.885-5.913 (149.48-150.19)
MPV 4WD
Front7.275-7.303 (184.78-185.50)
Rear8.022-8.051 (203.78-204.50)
Protege 4WD
Rear Differential5.910-5.913 (150.13-150.20)
RX7
Non-Turbo7.300-7.306 (185.43-185.59)
Turbo8.048-8.051 (204.43-204.50)
9298.023-8.051 (203.78-204.50)
(1)See Fig. 12 for measuring point.
ApplicationSpecification
Above 0° F (-18° C)GL-5/SAE 90w
Below 0° F (-18° C)GL-5/SAE 80w
(1)Fill to lower edge of filler plug hole.

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
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Sunday, July 05, 2009 2:17:01 PMPage 20 © 2005 Mitchell Repair Information Company, LLC.

Fig. 12: Measuring Carrier Case Spread
Courtesy of MAZDA MOTORS CORP.
TORQUE SPECIFICATIONS
1990 TORQUE SPECIFICATIONS (B2200 & B2600i)
ApplicationFt. Lbs. (N.m)
Brake Pipe Union10-16 (14-22)
Differential Assembly
Differential Carrier-to-Axle Housing17-20 (23-27)
Differential Carrier Bearings Cap Bolts
"P" Series Differential41-59 (56-80)
"M" Series Differential27-38 (37-52)
Differential Carrier
Bearings Lock Tab13-19 (18-26)
Drive Pinion Lock Nut94-130 (127-176) 90
Filler Plug29-40 (39-54)
Ring Gear Retaining Bolts51-61 (69-83)
Front Suspension & Differential
Drive Shaft Companion Flange20-22 (27-30)
Sub-Frame Mounting Bolts69-85 (94-115)

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
Microsoft
Sunday, July 05, 2009 2:17:01 PMPage 21 © 2005 Mitchell Repair Information Company, LLC.

1991 TORQUE SPECIFICATIONS (B2200 & B2600i)
1990 TORQUE SPECIFICATIONS (MIATA)
Splash Shield23-34 (31-46)
Rear Drive Axle
Axle Bearing Lock Nut145-217 (197-294)
Backing Plate Bolt
2WD72-87 (98-118)
4WD65-80 (88-109)
Drive Shaft Companion Flange20-22 (27-30)
Wheel Lug Nuts
Standard Wheel65-87 (88-118)
Styled Wheel87-108 (118-146)
ApplicationFt. Lbs. (N.m)
Brake Pipe Union10-16 (14-22)
Differential Carrier-To-Housing Nuts17-20 (23-27)
Differential Carrier Bearings Cap Bolts
"P" Series Differential41-59 (56-80)
"M" Series Differential27-38 (37-52)
Differential Carrier Bearings Lock Plate Bolt13-19 (18-26)
Drive Pinion Lock Nut94-210 (127-284)
Drive Shaft Companion Flange Nuts20-22 (27-30)
Filler Plug29-40 (39-54)
Front Subframe Mounting Bolts69-85 (94-115)
Rear Axle Bearing Lock Nut145-217 (197-294)
Rear Backing Plate Bolt
2WD72-87 (98-118)
4WD65-80 (88-109)
Ring Gear Retaining Bolts51-61 (69-83)
Splash Shield Bolts23-34 (31-46)
Wheel Lug Nuts
Standard Wheel65-87 (88-118)
Styled Wheel87-108 (118-146)
ApplicationFt. Lbs. (N.m)
Differential Assembly
Differential Carrier-to-Housing17-20 (23-27)
Differential Carrier Bearings Cap Bolts50-66 (68-90)
Differential Carrier Bearings Lock Tab14-19 (19-26)
Differential Case Rear Mounts
Drive Pinion Lock Nut87-130 (118-176)

1991 Mazda MX-5 Miata
1990-91 DRIVE AXLES Differentials & Drive Axles - 929, B2200, B2600i, MX-5 Miata, MPV, Protege & RX-7
Microsoft
Sunday, July 05, 2009 2:17:01 PMPage 22 © 2005 Mitchell Repair Information Company, LLC.