Recall 11V485 covers 179 2011 Tiffin Allegro Bus and Phaeton motorhomes for exhaust clamp failure. Repair is free at authorized Cummins dealers.
Tiffin is recalling 179 2011 Allegro Bus and Phaeton motorhomes under recall 11V485 because a V-band clamp T-bolt on the diesel exhaust aftertreatment system can fracture and let exhaust sections separate. Hot exhaust gases can vent before the tailpipe, raising fire risk, and the Tiffin dealer repair will be free once available.
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What's wrong?
The V-band clamp assembly on the 2011 Tiffin Allegro Bus and Phaeton motorhomes holds the inlet and outlet cone sections to the diesel oxidation catalyst and diesel particulate filter. That catalyst and filter housing is part of the diesel exhaust system. It helps treat soot and other exhaust material before gases move toward the tailpipe, and the clamp keeps those heavy exhaust sections tight against the housing.
On affected motorhomes, the clamp's T-bolt is the weak point. When the clamp is under stress or load, the T-bolt can fracture. Once the bolt breaks, the clamp loses its grip and the inlet or outlet cone section attached to the catalyst and filter housing can loosen or separate from the housing.
There is no warning sign before failure. An owner is not told to watch for a specific light, sound, or smell in the recall filing, so the VIN and the dealer inspection decide whether this repair applies.
Who's affected?
Covers two Tiffin motorhome lines from the 2011 model year, both tied to engine and engine cooling.
| 2011 Tiffin Allegro Bus | Engine and engine cooling |
|---|---|
| 2011 Tiffin Phaeton | Engine and engine cooling |
| Units affected | 179 |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific motorhome is included.
What's the safety risk?
If the inlet or outlet sections disconnect, hot exhaust gases can vent before leaving the tailpipe. That creates a fire risk. If both clamps fail, the DOC/DPF housing can detach completely and become a road hazard. Schedule the recall repair soon. Repair will be free at any franchised Tiffin dealer once available.
What should I do?
- Check your VIN to confirm your 2011 Tiffin Allegro Bus or Phaeton is included in this recall.
- Contact Tiffin or Cummins to confirm repair instructions before taking the motorhome in.
- Ask an authorized Cummins dealer about the free V-band clamp repair that keeps hot exhaust gases from venting near the DOC and DPF housing.
- Reference recall number 11V485 when you call, and bring the recall notice if you have it.
- Watch for exhaust noise, heat, or odor around the diesel aftertreatment system, and stop driving if you notice signs of an exhaust leak.
What happens at the repair
Tiffin worked with Cummins to identify and notify owners for this recall. At an authorized Cummins dealer, the repair addresses the V-band clamp assembly that connects the inlet and outlet cone sections to the DOC and DPF housing. Repairs are performed free of charge under the recall. The safety recall began on October 10, 2011. Owners can contact Cummins or Tiffin with recall questions before arranging service.
Timeline
| September 23, 2011 | NHTSA published the recall |
|---|---|
| October 10, 2011 | Owner notification mailed |
Frequently asked questions
What is recall 11V485?
Recall 11V485 covers 179 2011 Tiffin Allegro Bus and Phaeton recreational vehicles built on the PowerGlide chassis with certain Cummins diesel engines. A V-band clamp T-bolt can fracture, loosen the exhaust connection, and let hot exhaust gases vent before the tailpipe.
What should I do if my 2011 Tiffin Allegro Bus or Phaeton is on this recall?
Check your VIN to confirm your specific motorhome is included in recall 11V485. If it is, contact an authorized Cummins dealer to schedule the free repair. Reference recall number 11V485 when you call, and ask the service desk how they handle motorhome appointments.
Is the recall repair free?
Yes. Tiffin's recall remedy says authorized Cummins dealers will perform the repair free of charge. The safety recall began on October 10, 2011, so the dealer service desk can use recall 11V485 to confirm the campaign and repair path.
What is the safety risk?
The safety risk is fire and road debris. If the inlet or outlet sections disconnect, hot exhaust gases can vent before they exit the tailpipe, creating combustion and fire risk. If both clamps fail, the DOC/DPF housing presents a road-hazard risk.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/11V485000 |
|---|---|
| Tiffin customer service | 1-812-377-5000 |
| NHTSA recall # | 11V485 |
| NHTSA recall # (full) | 11V485000 |
Source documents
This article is generated from NHTSA's primary recall filings and reviewed against the source on June 2, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →