2. PMD Shim Calculation
Date :
Presenter

3. Rear Axle Sr. No. Axle Manufacturer Abbreviation Nomenclature PCVN 1
Axles India Limited
AIL
DANA
Thou 2
Automotive Axles Limited
AAL
MERITOR 3
American Axle Manufacturer
AAM
AMERICAN
Millimeter (mm)
Note:
PCVN needs to be converted from Thou to millimeter in case of Axles India & Automotive Axles differential assemblies.
In case of American Axles, since PCVN is already denoted in millimeter, conversion is not necessary.

4. Identification- Crown Wheel / Pinion – Dana & Meritor Axle
Rear Axle
Identification- Crown Wheel / Pinion – Dana & Meritor Axle
PART NUMBER
NO. OF TEETH ON CROWN WHEEL
MANUFACTURING NUMBERS
MATCHING GEAR SET NUMBERS
NO. OF TEETH ON PINION
DATE CODES
INDICATES GENUINE SPICER PARTS
HEAT CODE

5. Identification- Crown Wheel / Pinion – Dana & Meritor Axle
Rear Axle
Identification- Crown Wheel / Pinion – Dana & Meritor Axle
PCVN in Axles India Limited & Automotive Axles Limited are denoted in “Thou”.

6. Differential Carrier Assembly – Dana & Meritor (Solo Axle)
Rear Axle
Differential Carrier Assembly – Dana & Meritor (Solo Axle)
Shim Calculation: (Field)
If new gear set is installed adopt the following procedure to arrive at a correct mounting distance of drive pinion.
Note : Pinion Cone Variation number (or PMD Value) etched on removed Pinion.

7. Differential Carrier Assembly Dana & Meritor (Solo Axle)
Rear Axle
Differential Carrier Assembly Dana & Meritor (Solo Axle)
E.g. PMD +4 (Pinion Mounting Distance OR PCV)
If this number is a plus(+) subtract (-) the number from old shim pack thickness.
If it is minus (-), add(+) the number to old shim pack thickness.
The value arrived as above is the thickness of standard shim pack thickness.
If pinion the PMD value of new gear set is (-) minus, subtract the number from standard shim pack thickness.
If it is plus (+), add to standard pack thickness.

8. Shim Calculation Dana & Meritor (Solo Axle)
Rear Axle
Shim Calculation Dana & Meritor (Solo Axle)
Old Shim Pack Thickness
0.8mm
Old PMD +4
Standard shim pack ? +6
New PMD
New Shim Pack Thickness ?
Addition / Deletion of shims needed ?
DESCRIPTION MM
SHIM SIZE
Old Shim Pack Thickness
0.8
Old PMD +4 Thou (- 0.10mm)
- 0. 1
-0.1
Standard shim pack
0.7
New PMD +6 Thou (+ 0.15mm)
0. 15
0.15
New Shim Pack Thickness
0.85
Addition / Deletion of shims needed
0.05
=0.05
In Simple if Old PCVN is “+” then subtract and later if New PCVN is “+” then add

9. Shim Calculation Dana & Meritor (Solo Axle)
Rear Axle
Shim Calculation Dana & Meritor (Solo Axle)
Old Shim Pack Thickness
0.8mm
Old PMD
- 4
Standard shim pack ? +6
New PMD
New Shim Pack Thickness ?
Addition / Deletion of shims needed ?
DESCRIPTION MM
SHIM SIZE
Old Shim Pack Thickness
0.8
0.80
Old PMD -4 Thou
0.1
0.10
Standard shim pack
0.90
New PMD +6 Thou
0.15
New Shim Pack Thickness
1.05
Addition / Deletion of shims needed
0.25
=0.25

10. Shim Calculation Dana & Meritor (Solo Axle)
Rear Axle
Shim Calculation Dana & Meritor (Solo Axle)
Old Shim Pack Thickness
0.8mm
Old PMD
+ 4
Standard shim pack ?
- 6
New PMD
New Shim Pack Thickness ?
Addition / Deletion of shims needed ?
DESCRIPTION MM
SHIM SIZE
Old Shim Pack Thickness
0.8
Old PMD +4 Thou
- 0.1
-0.1
Standard shim pack
0.7
New PMD -6 Thou
-0.15
New Shim Pack Thickness
0.55
Addition / Deletion of shims needed
-0.25
= -0.25

11. Shim Calculation Dana & Meritor (Solo Axle)
Rear Axle
Shim Calculation Dana & Meritor (Solo Axle)
Old Shim Pack Thickness
0.8mm
Old PMD
- 4
Standard shim pack ?
- 6
New PMD
New Shim Pack Thickness ?
Addition / Deletion of shims needed ?
DESCRIPTION MM
SHIM SIZE
Old Shim Pack Thickness
0.8
Old PMD -4 Thou
0.1
Standard shim pack
0.9
New PMD -6 Thou
-0.15
New Shim Pack Thickness
0.75
Addition / Deletion of shims needed
- 0.05 =

12. Identification- Crown Wheel / Pinion - American Axle
Rear Axle
Identification- Crown Wheel / Pinion - American Axle
1 – Part Number
2 – Set Number
3 – Charge Number
4 – Ratio
5 – Depth Setting
PCVN in American Axles Manufacturers are denoted in “mm”.

13. Shim Calculation American Axle
Rear Axle
Shim Calculation American Axle
Shim calculation procedure for American, Dana & Meritor solo remains the same except the PCVN in American is denoted in millimeter & in THOU for Dana & Meritor
Old Shim Pack Thickness
0.8mm
Old PMD
Standard shim pack ?
New PMD
New Shim Pack Thickness ?
Addition / Deletion of shims needed ?
DESCRIPTION MM
SHIM SIZE
Old Shim Pack Thickness
0.8
0.800
Old PMD – 0.254
0.254
Standard shim pack
1.054
New PMD
-0.376
New Shim Pack Thickness
0.678
Addition / Deletion of shims needed =

14. Inter Axle Gear Set Information
Meritor Inter axle (Tandem first axle)

15. Inter Axle Shim Pack Setting
Meritor Inter axle (Tandem first axle)
If a new ring gear and pinion are to be installed, the correct thickness of the shim pack between the Inner bearing and the carrier must first be determined.
Follow these procedures:
Adjust Thickness of Shim Pack for Hypoid Pinion (Depth of Pinion)
NOTE:
Use this procedure if a new hypoid pinion and a ring gear set Is Installed, or If the depth of the original pinion has to be adjusted
1. Use a micrometer to measure the thickness of the shim pack that was removed from the differential carrier. Record the-measurement for later use
2. Look at the pinion cone ('PC') variation number on the hypoid pinion that is being replaced. Record the number for later use.

16. Inter Axle Shim Pack Setting
Meritor Inter axle (Tandem first axle)
3. If the old pinion cone number is a plus (+), add the cone number to the thickness of the old shim pack that was measured in Step 1.
4. If the old pinion cone number is a minus (-), subtract the cone number from the thickness of the old shim pack that was measured in Step 1.
5. Look at the pinion cone (PC) variation number on the new pinion that will be installed. Record the number for later use.
6. If the new pinion cone number is a plus (+), subtract the number from the standard shim pack thickness that was calculated in Step 3 or 4.
7. If the new pinion cone number is a minus (-), add the number to the standard shim pack thickness that was calculated in Step 3 or 4.
8. The value calculated in Step 6 or 7 is the thickness of the new shim pack to be installed.

17. Inter Axle Shim Pack Setting
Meritor Inter axle (Tandem first axle)
Example mm
Old Shim Pack Thickness
Old PC Number, PC
Standard Shim Pack Thickness
New PC Number, PC
New Shim Pack Thickness
Example mm
Old Shim Pack Thickness
Old PC Number, PC
Standard Shim Pack Thickness
New PC Number, PC
New Shim Pack Thickness

18. Inter Axle Shim Pack Setting
Meritor Inter axle (Tandem first axle)
Example mm
Old Shim Pack Thickness
Old PC Number, PC
Standard Shim Pack Thickness
New PC Number, PC
New Shim Pack Thickness
Example mm
Old Shim Pack Thickness
Old PC Number, PC
Standard Shim Pack Thickness
New PC Number, PC
New Shim Pack Thickness