Whilst speaking with an operator recently, the question came up about whether it was possible to save time and money by not replacing the damper.
We gave them the full technical explanation and it made me think that it was worth putting together the correct protocol when it comes to the dampers in your critical diesel engine, to help you make the right decisions.
There are two types of dampers: viscous and rubber bonded.
Viscous dampers come in two variants:
1. Disposable – these need to be replaced every 10 years OR every 20,000 hours
2. Rechargeable – these need to be serviced every 10 years OR every 20,000 hours.
The benefit of a rechargeable damper is that they have a port where you can monitor the viscosity regularly to detect any issues.
With viscous dampers, the fluid becomes solid over time and forms an uneven mass on the bottom of the damper. When the engine runs, this then spins in an elliptical manner, which can lead to a snapped crankshaft.
Viscous dampers should not be painted, as this traps the heat and reduces the life of the damper; they should only be coated lightly with oil or lacquer.
MTU engines have engine oil-fed dampers, so on each oil change they are flushed, and the oil is renewed. They still need to be replaced at the recommended interval.
Rubber bonded dampers must be changed every 10 years OR 20,000 hours.
They must have no visible signs of damage and it is vital they are stored flat. Some OEMs mark their rubber-bonded dampers, so it is easily visible when they are out of alignment.
The damper above shows little sign of damage so could have easily been overlooked and left. (Luckily it wasn’t as we did find it to be “out”.)
As always, there are ways to save money on every job, but not following the recommended guidelines or even the engineer’s advice can lead to massive cost in the future; would you rather have the added expense of a new damper during overhaul or a new crankshaft down the line?
