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What is a Vibratech TVD viscous damper, and why does your heavy duty diesel truck need one?

May 12, 2021

First, torsional vibration is created each time a cylinder is compressed, causing the crankshaft to rotate. These forces are so severe that they twist the crankshaft ahead of its natural rotation causing it to rebound. This twisting motion is what create torsional vibration, a.k.a. engine harmonics, and subsequently allows it to transmit through the crankshaft reaching other critical components such as engine bearings, valve train components, oil pump gears, and even though the flywheel end into the drivetrain or cabin in which the driver is located. To remediate these destructive vibrations, a vibration damper is mounted to the crankshaft to counteract the crankshaft twist. However, you cannot wholly eliminate engine vibrations, and you can only do your best to reduce them from breaking expensive engine parts and rattling the teeth of vehicle occupants. 

There are different types of vibration dampers. The most common in heavy duty diesel or over-the-road truck applications is a viscous vibration damper. The viscous damper was invented by Vibratech TVD (formerly Houdaille) in 1946 to provide durability to commercial diesel engines, i.e., trucks, trains, gen-sets, etc. Vibratech is still manufacturing 100% Made in the U.S.A. products today for various OE and aftermarket applications. A viscous damper is made up of 3 main components, as shown in the illustration below, a laser-welded and hermetically sealed housing, an internal inertia ring, and very thick silicone fluid. (45,000 thicker than 30w engine oil). (see Illustration 1:2 below)

Components that make up of viscous crankshaft damper


Unfortunately, the damper is a commonly overlooked item by service centers. We believe this is because it is tough to determine if a viscous damper needs replacement. In many cases, a damper due for replacement looks the same on an engine with 1,000,000 miles or more as the day it came from the manufacturer-new. Vibratech -TVD recommends replacing the viscous damper at 500,000 miles or 15,000 operation hours intervals. This is due to the continuous working action of the internal inertia ring shearing through the silicone fluid, which will eventually cause the fluid to polymerize and lock the inner inertia ring (see illustration 1:3 below). At this point, your viscous damper has just become a solid counterweight on the end of the crankshaft. It is only a matter of time until there is crankshaft failure and catastrophic engine failure. As any trucker knows, downtime hits your pocketbook. Be safe, be smart, change your engine damper! Happy Trucking!

Time and Mileage Cause All Parts To Fail - This is an example of a  Failed Heavy Duty Viscous Vibration Damper

KLM Performance has been an Authorized Vibratech TVD Distributor since 2005. We believe in selling the highest quality American-Made products to keep our customers on the road making money.

KLM Performance offers the Vibratech Viscous Heavy Duty Crankshaft Dampers for these diesel engines:

Please feel free to Contact Us if you have any questions regarding a Heavy Duty Damper for your diesel engine!

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