D11 Track Master Link Improved Design Caterpillar

Summary

The master links in the D11 T/R/N track have changed from a five tooth serrated design to a Single Tooth design.

Benefits

The new design uses one large single tooth along with a wider link cross-section to improve resistance to link cracking. They also use Metric (M36) coarse threads to reduce occurrence of thread stripping.

These features help to reduce or in some circumstances eliminate the need to replace master links at the bushing turn service interval. As a result, customer expenses will be reduced. The new Single Tooth Master Link also increases reliability to the overall system.

                 Illustration 3 ? ?Pin End? Single Tooth Master Link;                          Illustration 4 ? Coarse vs Fine Thread

Coarse Thread Shipping Plugs

The 358-6555 Master Link ? Pin End RH and 358-6556 Master Link ? Pin End LH each consist of a ?pin end? or ?threaded? half link and two coarse thread shipping plugs installed.  The plug is intended to protect the threads and should stay in place until the track is assembled on the tractor. 

 M36 Coarse Thread Bolts vs Former Fine Thread 1 3/8? bolts

The plug (see illustration 3) is also intended to be a visual indicator to use the new M36 coarse thread bolts instead of the former fine thread 1-3/8? bolts (see illustration 4).  The coarse thread bolts must be used with the Single Tooth Master Links. Failure to do so may cause thread stripping, link damage and possibly track separation.

Track Shoes Used With New Single Tooth Master Links

Illustration 5 ? Track shoes used with new Single Tooth Master Links (link joints separated for clarity)

(A) ?Current track shoe on current track full link - no changes
(B) ? Master track shoe - different bolt hole diameter and pattern than former master shoe
(C) ?Joint 2 shoe (full link adjacent to bushing end master link) - wider mud notch and narrow center tab
(D) ?New Single Tooth Master Links with wider bushing end master link
The track shoes used with the new Single Tooth Master Links have also changed.  The new Single Tooth Master Link shoe has a different bolt hole diameter and pattern than the former master shoe.  Also, the shoe adjacent to the bushing end master links has wider mud notches to prevent interference with the wider Single Tooth Master Links.  This shoe is referred to as the ?Joint 2 shoe?.  See Illustration 5.

Regular Track Shoes Can Be Modified

A regular track shoe can be modified in the field in order to fit the specifications of the ?Joint 2 Shoe?. See illustration 6 for proper dimensions.

New Single Tooth Master Bolt Installation Location

Illustration 7 ? New Single Tooth Master Bolt installation location

(G) ? 360-2472 master bolt; M36 x 4 thd; 183 mm long
(H) ? 360-2473 master bolt; M36 x 4 thd; 153 mm long

Torque Turn Values Have Changed

"To ensure proper master link life and bolted joint integrity, the specified
torque plus turn procedure must be properly followed.  Note that 5 Tooth and Single Tooth torque turn angle values are different as the bolts have different threads."

 Note:  This is a change from the old five tooth serrated master links and bolts that used a 180? degree turn.

Illustration 8 ? bolt torque pattern

Undercarriage Reconditioning Bulletins for Single Tooth Master Links

SEBF8620 Reusability Guidelines for Single Tooth Master Links 

SEBF8621 Shop Disassembly and Assembly of Single Tooth Master Links 

SEBF8622 Field Removal and Installation of Single Tooth Master Links

Additional Information

The new master links are not compatible with the old master links in the same track. If one of the former five tooth design master links has failed, then all four half-links must be replaced with the new single tooth design.

The new Single Tooth Master Links will be initially available only with standard height D11 link assemblies. 

They will be offered with the D11 High Abrasion/Tall link assemblies at a later date.

See Table Below for Parts List Cross Reference

*The service effective date for High Abrasion Track Groups is Jan 2013. The service effective date for all other track groups is Dec 2013.

Contact Information:

                        Global Dealer Solutions Network
                        Parts Technical Support Team
                        Toll Free - North America:  1-877-228-2420
                        International: +1-309-266-4421
                        Electronic Requests:
                       Send via Microsoft Customer Relationship Management (MSCRM)
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