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9 01-14

SUBJECT

DATE

Forward-Rear Tandem Pinion Bearing

September 2014

Additions, Revisions, or Updates
Publication Number / Title

Platform

Section Title

Change

DDC-SVC-MAN-0141

Detroit Axles Manual

Installation of the Front Rear Tandem
(FRT) Pinion Bearing

Updated for clarification.

All information subject to change without notice.

9 01-14

Copyright © 2014 DETROIT DIESEL CORPORATION

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2 Installation of the Front Rear Tandem (FRT) Pinion Bearing

2

Installation of the Front Rear Tandem (FRT) Pinion Bearing

Install as follows:
1. Ensure bearing race bore is free of nicks, dents, and debris. If nicks are present, they should be polished smooth. Install
"c" dimension tools DDE W420589001902(1) and W4200589001901(2). Make sure they are flush against each other.

2. Install dial indicator; measure difference in the heights noted in the images below. This difference will be used for step
2 of the below calculation.
Table 1.
Model 4 FRT Pinion Bearing Calculation

4

1.

Tool Dimension (This is the height of the tool)

2.

Measured Difference

248.740

3.

Equals line 1 minus line 2

4.

Measured Bearing Height (Measurement provided in parts kit)

5.

Equals line 3 minus line 4

6.

Standard Value (This value is constant and does not change)

7.

Desired Shim Thickness (Equals line 5 minus line 6)

196.500

All information subject to change without notice.

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9 01-14

3. Remove all tooling.
4. Using bearing driver DDE W420589001504 (1) along with DDE W420589001502 (2) and a suitable press, install new
tail bearing race.

All information subject to change without notice.

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Copyright © 2014 DETROIT DIESEL CORPORATION

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2 Installation of the Front Rear Tandem (FRT) Pinion Bearing

5. Prior to shim installation, wipe clean any debris or oil from the new bearing. The pinion will need to be installed with
the race dry. If any lube is added, the pinion rotating torque will be affected. Install shim(s), if necessary. There may be
more than one shim(s) being installed into head bearing race cavity. If so, then install race using DDE W420589001504
along with DDE W420589001502.

6. Using locally sourced bearing remover, remove old bearing from pinion gear.

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7. Use bearing installer DDE W420589001503, press a new pinion head bearing into place.

8. Install the pinion bearing spacer.

All information subject to change without notice.

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2 Installation of the Front Rear Tandem (FRT) Pinion Bearing

9. Install temporary shim (2.50 test shim is provide in the kit). Install onto pinion.

10. Install pinion into carrier. It is necessary to support from underside.

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11. Using bearing installer DDE W420589001503 and a suitable press, install the tail bearing onto pinion shaft.

12. Remove bearing installer.
13. Install counterholder.

All information subject to change without notice.

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Copyright © 2014 DETROIT DIESEL CORPORATION

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2 Installation of the Front Rear Tandem (FRT) Pinion Bearing

14. Install yoke nut measuring device using a 56 mm (2 3/16-in.) 12-point socket; torque to 300 N·m (220 lb·ft), then rotate
pinion three revolutions. Torque to 900 N·m (663 lb·ft), then rotate pinion three revolutions. Torque to final setting of
1200 N·m (886 lb·ft).
15. Install push-pull arm.
16. Install dial indicator.

17. Pull down on arm to check end play on pinion. Rotate the pinion several times with the pivot arm in the up and down
position in order to fully seat the pinion bearings to get an accurate measurement. Example: Take the end play
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All information subject to change without notice.

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18.
19.
20.
21.

measurement and subtract that from the size of the shim installed. Our shim was 2.36mm (0.093 in.). Our end play was
0.220 mm (0.0086 in.). For the calculation, subtract 0.05 mm (0.002 in.) - this is a standard value needed to calculate
the preload: 2.36 mm - 0.22 mm - 0.05 mm (0.093 in. - 0.0086 in. - 0.002 in.). Proper size of tail shim for preload is
2.09 mm (0.082 in.). Verify size of shim with micrometer.
Remove all special tools.
Using press, press the pinion back out of the carrier housing
Remove test shim and then install the correct shim based off of the measurement above.
Supporting pinion from below, guide pinion into housing; do not fully seat at this time. Install spacer, then shim onto
pinion. Install upper bearing and then slide helical gear into housing. Continue to raise pinion into carrier, aligning onto
pinion splines with the helical gear. Using bearing installer tool DDE W420589001503, press gear and bearing back
onto pinion shaft.

22. Install pinion nut. Wooden blocks can be used to prevent pinion from rotating while tightening nut. Torque to 1200
N·m (886 lb·ft); check rotating torque. Torque should be between 7 to 25 N·m (5 to 18 lb·ft). If OK, remove pinion
nut, and apply lube to bearing. Apply Loctite 277 to threads. Re-torque to 1200 N·m (886 lb·ft) and stake the pinion
nut. If turning torque is too high, increase shim size. If turning torque is too low, decrease shim size.
23. Reinstall the ring gear. Refer to section "Rebuilding of the Differential"
24. After ring gear installation, it is necessary to check the pinion and ring gear tooth contact pattern. Apply gear marking
compound to 4 to 6 teeth of the ring gear. Cover both the drive and coast side. Rotate the ring gear forwards and
backwards so pinion teeth have been fully engaged with paint marks on ring gear. Be sure that a contact pattern can be
observed. See examples below.

All information subject to change without notice.

9 01-14

Copyright © 2014 DETROIT DIESEL CORPORATION

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2 Installation of the Front Rear Tandem (FRT) Pinion Bearing

Table 2.
Good Tooth Contact Pattern

High Tooth Contact Pattern – increase pin head shim size

Low Tooth Contact Pattern – decrease pinion head shim size

25. Reinstall Interaxle Differential (IAD). Refer to section “Replacement of the Interaxle Differential”.

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All information subject to change without notice.

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