Muffler Assembly for Cat 561M Pipelayer & D5M Track Tractor 1737129

Fits Models At A Glance:

Caterpillar Pipelayers:

• 561M

Caterpillar Track-Type Tractors:

• D5M (including LGP and XL)

Key Notes:

• Part Numbers: 1737129, 173-7129
• Replaces: 115-8408 (earlier part number)
• Weight: 26.00 lbs (11.82 kg)
• Dimensions: 76.00 cm wide × 24.00 cm deep
• Engine: Fits machines with the Cat 3116 engine
• Type: Exhaust muffler assembly
• Condition: Aftermarket replacement part
• Application: Reduces engine noise and routes exhaust gases away from the machine on the 561M pipelayer, D5M track-type tractor (including LGP and XL), and the CX31-C11I petroleum package
• Note: This is the M-series muffler and replaces the earlier 115-8408 — confirm your serial number if replacing an original 115-8408. The later D5N / 561N use a different part

Common Use Case or Symptoms:
Use when the muffler is rusted through, leaking exhaust, excessively loud, or physically damaged — a failed muffler allows exhaust gases and noise to escape at the machine rather than being routed away safely.

Why Choose Broken Tractor:
✅ Direct-Fit for the M-Series 3116 Engine Platform — matched to the 561M, D5M, and CX31-C11I exhaust application
✅ Replaces the Earlier 115-8408 — the updated muffler assembly for these M-series machines
✅ Fast Shipping from a U.S.-Based Team — ready to ship from our U.S. warehouses