1999/07/05 Caterpillar

Improved Drawbar/Three-Point Hitch Increases Durability {7120}

Usage:

Challenger 35 (8DN, 8RD, ADK),
Challenger 45 (1DR, ABF, 3BK),
Challenger 55 (7DM, 6NN, AEN) Agricultural Tractors

Reference: Service Magazine, SEPD0368, July 7, 1997, Page 4, "Improved Three-Point Hitch Rockshaft Seal and Wear Ring Prevents Dirt Packing".

Description of Change: An improved three-point hitch and drawbar design is now available. The new design incorporates several improvements to the previous design. Listed below are the improvements to the previous design:

Drawbar

* Construction is thicker, the clevis is heavier

* Drawbar pin is a non-rotating design

* Includes wearplates and stops

* Front drawbar pin is a flagpin design

Draft Arms

* Made of a stronger one-piece design, and shortened to improve tractor balance

* Have repairable spherical bearings and are interchangeable left hand to right hand sides

* The support design is changed to give additional clearance with the lower arm spherical bearings

Quick Hitch

* Bolt-together design rather than a weldment

* Shorter fore/aft to improve tractor balance

Adaptable To: The improved drawbar/three-point hitch is effective with first production of the 1999 model year Challenger 35, Challenger 45, and Challenger 55 Agricultural Tractors. The improved design is adaptable to all earlier rowcrop Challenger Agricultural Tractors.

All the drawbar parts listed must be installed as a group along with the three-point hitch parts. However, the former quick hitch and/or the former top link can be adapted for use with the improved design, if desired.

Use Of Former Quick Hitch With Former Top Link

If a former quick hitch is used with the former top link, the welded-in spacers at the quick hitch draft arm connection must be split in order to center the improved draft arms. The existing spacer can be cut in half, or a new spacer can be made and the old one ground down. Then weld the new spacer on the side of the draft arm opposite of the reworked existing welded-in spacer. See Illustration 1.

Illustration 1.

(AA) Inside Frame (Quick Hitch)

(AB) 7.94 mm (.313 in)

(AC) 37.033 ? 0.127 mm (1.458 ? .005 in) diameter

(AD) 69.85 mm (2.750 in) diameter

(AE) Weld

(AF) Remove 7.94 mm (.313 in) of material from existing quick hitch spacer

(AG) 7.94 mm (.313 in)

(AH) 47.63 mm (1.875 in)

Use Of New Top Link And New Quick Hitch

Install a 153-7571 Bushing in the tractor end of the top link. Then install top link on tractor.

Use Of Former Top Link With The New Quick Hitch

If using the former top link with the improved quick hitch, a 133-5333 Bushing is used at the top quick hitch pin to bush down the quick hitch ears to the smaller top link pin diameter. The hole diameter in the quick hitch must be increased from 37 mm (1.456 in) to 37.47 ? 0.13 mm (1.475 ? .005 in). This is required to accommodate the size of the bushing. Then a 152-0781 Pin Assembly is used to connect the quick hitch to the former top link.

Miscellaneous Information

* The left hand lift arm may interfere with PTO lube lines. The lube line tubes may have to be slightly bent.

* The existing draft pin covers bolt on to the new draft pin retainers (if equipped).

* Electrical connectors can be reworked to Deutsch connectors (if equipped with draft control). See Table 1 and Illustration 2 for additional information.

Illustration 2.

* Make sure to recalibrate the position sensor.

* Rockshaft seals and wear rings should be inspected and replaced while lift arms are removed from rockshaft. See the reference service magazine article.

See the following tables and illustrations for a complete parts list and for the location of parts.