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Recreation Tech Tip
September 2000
2300 Recreation
0023-2310-MTDC
Ripper Retrofit for the Sweco 480 Trail Dozer

Bob Beckley, Project Leader

The Sweco 480 Trail Dozer (Figure 1) is a 4-foot-wide minidozer that can perform a wide variety of forest operations. This 80-horsepower dozer is 11 feet and 1 inch long and has a ground pressure of 7.3 psi. It is easily transported, is cost effective, and is available commercially.

Picture of the ripper system on the Sweco 480 Trail Dozer. In the picture, an arrow is pointing to the labeled ripper system.
Figure 1—The Sweco 480 Trail Dozer.
The ripper is mounted behind the dozer.

Two types of ripper systems can be used on the Sweco 480 Trail Dozer. The older version consists of a 4- by 4-inch square steel tubular bar ¼ inch thick. The newer version of the ripper system consists of a 4- by 6-inch square steel tubular bar 5/16 inch thick. The rippers are placed in three slots cut into this bar. These slots are 2½ inches long and ¾ inch wide. The individual rippers are 2 3/8 inches across the top flat and 11/16 inch wide. A metal wedge or spring keeper holds the rippers in place.

Earlier versions of the Sweco 480 Trail Dozer Ripper System may require modification to ensure that the individual rippers fit securely.

The slots these rippers fit into may become elongated through use, allowing the rippers to fall out. A common cause of this problem is backing up without first raising the ripper system. The spring keeper or wedge is made of a softer metal than the ripper. The keepers lose their shape, allowing the rippers to fall out.

A simple low–cost modification can eliminate the problem caused by elongated ripper slots. This modification can be done by most skilled welders or a metal fabrication shop. This modification takes about 2 hours. The steps are as follows:

  • Weld hardface to the inside of the elongated hole, restoring it to its original size of 2½ inches long by ¾ inch wide.

  • Weld a piece of keystock ¾ by ¾ by 2 inches long to the bottom backside of the square tubular steel bar. The keystock should be flush with the back of the slot the ripper fits into (Figure 2).

  • Weld a piece of keystock ¾ by ¾ by 2 inches long to the top front of the square tubular steel bar ½ inch in front of the slot the ripper fits into (Figure 3).

  • Replace rippers in the slot. Secure the rippers with new wedges or spring keepers.

Photo of a weld keystock flush focusing on the back of the ripper slot. In the photo the parts are labeled with an arrow pointing to each part. The labels read, Spring keeper, Ripper, Keystock and Tubular bar.
Figure 2—Weld keystock flush with the bottom back of ripper slot.

Photo of the weld keystock showing its placement, which is located ½ inch away from the front of the ripper slot. In the photo there is an arrow and label showing the ½ inch gap.
Figure 3—Weld keystock ½ inch in front of the top front of the ripper slot.

The manufacturer recommends either outershield welding or stick welding using welding rod LH–7018 (either 1/8 inch or 5/32 inch) at 125 to 130 amps.

This modification will secure the rippers and should prevent future failure or loss of rippers.

Newer versions of the Sweco 480 Trail Dozer ripper systems include this modification. A new ripper system costs $500 to $600 from the factory. The manufacturer can be reached at:

Sutter Equipment Co.
80 Chambelain Ave.
Novato, CA 94947
Phone: (415) 898-5955