OEM replacement exhaust pipe clamp for 1-1/4" outer diameter Cummins Onan RV generator exhaust pipe. Includes clamp and mounting hardware. 90-day limited warranty. Also listed as 98-0309.
The Cummins Onan 155-1256 is a genuine OEM exhaust pipe clamp for Cummins Onan RV generators. It secures exhaust pipe connections to prevent loosening from vibration, thermal cycling, and road movement. Sold as a single clamp with mounting hardware included.
This clamp fits exhaust pipe with a 1-1/4" outer diameter (O.D.). See the yellow callout below for an important note on how this clamp is stamped and how to confirm the right fit for your generator.
Designed to clamp exhaust pipe with a 1-1/4" outer diameter — the standard size used on many Cummins Onan RV generator exhaust systems
Includes one (1) clamp and the mounting hardware needed for installation — no additional fasteners required
Cummins Onan factory part — engineered to OEM specifications for proper fit and long-term durability in RV exhaust applications
Also sold under part number 98-0309 — both numbers refer to the same clamp and are interchangeable when ordering
This clamp will be physically stamped or marked "1-1/8"" — this is the inner diameter (I.D.) of the tubing it clamps. However, per Cummins Onan drawings and technical documentation, the clamp is specified to fit 1-1/4" outer diameter (O.D.) pipe. The two measurements differ by 1/8". To summarize: • Pipe O.D. this clamp fits: 1-1/4" • Pipe I.D. this clamp fits: 1-1/8" • Stamped on the clamp: 1-1/8" If you are matching by the number stamped on your old clamp, a clamp marked "1-1/8"" is the correct replacement — that is this part.
• One (1) Exhaust Pipe Clamp • Mounting Hardware Complete hardware for a standard installation. No additional fasteners required.
Backed by a 90-day limited manufacturer's warranty against defects in materials and workmanship. Retain your purchase receipt and note the installation date for any warranty service requests.