# Service bulletin 21TS\-06

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10191070
- Published by NHTSA: 2021\-05\-01
- Manufacturer's number: 21TS\-06
- Manufacturer's date: 2021\-04\-19
- NHTSA component: ENGINE AND ENGINE COOLING

## NHTSA's summary

Detroit Technical Service Letter for Gen 5 DD15 Exhaust Valve Adjusting Screw Excessive Wear. Some Detroit Heavy Duty Gen 5 DD15 engines are experiencing exhaust valve bridges that fall out of position while running. The engine may experience conditions such as rough running, misfire, or popping out of the intake. Misfire or exhaust pressure fault codes may also be present. Excessive valve lash caused by a worn rocker arm adjusting screw foot results in the valve bridge falling off the exhaust valves.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10191070-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10191070-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- FCCC FCCC
- FREIGHTLINER FREIGHTLINER
- STERLING STERLING
- THOMAS BUILT BUSES THOMAS BUILT BUSES
- WESTERN STAR WESTERN STAR

JSON: [/v1/bulletins/10191070](/v1/bulletins/10191070)

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