Middle Gear Inspection and Reassembly

INSPECTION

1. Check
• teeth of middle gear for discoloration/Pitting/Wear. If necessary, replace all middle gears as a set.
• Damper cam surfaces for wear/Unsmooth action. Replace if necessary.

2. Check bearing movement. Rotate the race by finger and replace if rough. 

ASSEMBLY AND ADJUSTMENT

1. Select proper middle-drive-gear shim.

NOTE:
Select proper middle-drive-gear shim whenever crankcase and/or middle gears are replaced.

Shim thickness calculation:

Calculate shim thickness using formula below:

Shim thickness (A) = c - a - b
a = 43 plus or minus the number printed on end of middle drive shaft.
b = a bearing thickness. (Considered constant)
c = 60 plus the number found on the upper crankcase half near the main bearing selection numbers:

For example: 
If middle drive shaft is marked "+03" and crankcase is tamped "45".

a= 43 + 0.03 = 43.03 mm
c= 63 + 0.45 = 60.45 mm
b= 16.94 mm (Constant) 
A = 60.45 - 43.03 - 16 .94 = 0.48 Calculated shim thickness is 0.48 mm.

Available shim thickness: 0.15 mm, 0.30 mm, 0.40 mm, 0.50 mm

Because shim can only be selected in 0.05 mm increments, use following chart to round off the hundredths digit of calculated thickness, and select appropriate shim.

In above example, calculated shim thickness is 0.48 mm. The chart instructs you, however, to round off the 8 to 10. Thus you should use two 0.50 mm shims.

2.  Install: 
• Middle drive shaft bearing.
• Middle drive pinion
• Lock washer (New)
• Nut

3.  Tighten the nut

4. Bend lock washer of nut into middle drive shaft slot using a center punch.

5. Assemble:
• Damper cam 1
• Spring 2  
• Spring seat 3  
• Spring retainer 

Use a Press and Damper Compressor (90890-04090)4.

NOTE:
Install the driven damper cam onto the drive pinion shaft with the cam lobes positioned 90° from the row of shaft oil holes 1. Positioning tolerance is ±1 spline (15°) from the 90° position.

Middle Drive Shaft Nut: 110 Nm (11 m-kg, 8 0 ft-lb)

6. Install:
• Bearing housing (onto the drive pinion shaft)
• Flange
• O-ring (New) (onto the drive pinion shaft)

7. Tighten: 
• Flange holding nut

Flange Holding Nut: 90 Nm (9.0 m-kg, 65 ft-lb) LOCTITE®

8. Lock the thread on the holding nut with a center punch.