Mazda MX-5 Miata / Grand Touring. Manual - part 56

Fig. 41: Measuring Drive Pinion Preload 
Courtesy of MAZDA MOTORS CORP. 

ADJUSTMENT SHIM ASSEMBLY NOTE 

Ring Gear Backlash Adjustment 

1. Stack the side bearing race and differential gear case component on the surface plate as shown in Fig. 42 

and measure the height using a caliper and a ruler. This is value A. 

Standard Height A  

151.4-152.6 mm {5.961-6.007 in}  

 

2008 Mazda MX-5 Miata Grand Touring 

2008 DRIVELINE/AXLES Differential - MX-5 Miata

  

Fig. 42: Measuring Height Using Caliper & Ruler 
Courtesy of MAZDA MOTORS CORP. 

2. Measure the width of the section of the differential gear case component installed in the differential 

carrier. This is value B. 

Standard width B  

171 mm {6.73 in}  

 

2008 Mazda MX-5 Miata Grand Touring 

2008 DRIVELINE/AXLES Differential - MX-5 Miata

  

Fig. 43: Measuring Width Of Differential Gear Case Component In Differential Carrier 
Courtesy of MAZDA MOTORS CORP. 

1. The combined thickness of the left and right adjustment shims is obtained by the following formula. 

Shim thickness (mm {in}) =B-A+ (0.01-0.03 {0.0004-0.0118 in})  

2. If the combined thickness of the previously assembled adjustment shims is equal to the calculated 

thickness, use the shims as they are.  

3. If the combined thickness of the previously assembled adjustment shims is not equal to the calculated 

thickness, or if the adjustment shims have to be replaced, select two appropriate adjustment shims from 
the table below. 

ADJUSTMENT SHIM TABLE 

Identification mark

Thickness (mm {in})

Identification mark

Thickness (mm {in})

550

5.50 {0.217}

605

6.05 {0.238}

560

5.60 {0.220}

610

6.10 {0.240}

565

5.65 {0.222}

615

6.15 {0.242}

570

5.70 {0.224}

620

6.20 {0.244}

575

5.75 {0.226}

625

6.25 {0.246}

580

5.80 {0.228}

630

6.30 {0.248}

585

5.85 {0.230}

635

6.35 {0.250}

 

2008 Mazda MX-5 Miata Grand Touring 

2008 DRIVELINE/AXLES Differential - MX-5 Miata

  

4. Assemble the differential gear case component and the side bearing race to the differential carrier.  

5. Tap the selected adjustment shim between the differential carrier and the side bearing race with a plastic 

hammer as shown in Fig. 44 . 

Fig. 44: Tapping Selected Adjustment Shim Between Differential Carrier & Side Bearing Race 
With Plastic Hammer 
Courtesy of MAZDA MOTORS CORP. 

6. Align the bearing cap alignment marks, assemble the bearing cap, and then temporarily tighten the bolts.  

7. Install the dial gauge with the measuring probe of the dial gauge attached perpendicularly to the end of 

one of the ring gear teeth. 

590

5.90 {0.232}

640

6.40 {0.252}

595

5.95 {0.234}

650

6.50 {0.256}

600

6.00 {0.236}

-

-

NOTE:



If the adjustment shims are to be reused, assemble the left and right 
shims that were identified during disassembly.  



When assembling the side bearing races, do not mix the left and right 
side bearings that were identified during disassembly.  

 

2008 Mazda MX-5 Miata Grand Touring 

2008 DRIVELINE/AXLES Differential - MX-5 Miata