The hard life of Damper Plates
This Tech Tip, one in ongoing series we publish for Hurth and Borgwarner Velvet Drive marine transmission owners, is aimed at helping people understand their marine damper plates. This Tech Tip follows other Tech Tips that discuss Hurth marine transmissions:
- Tech Tip #22: Hurth Gears: Care and Maintenance,
- Tech Tip #78: Hurth Marine Transmissions: The Ins and Outs of Basic Service,
- Tech Tip #96: ZF/Hurth Marine Transmissions: A Six Step Program.
We also discuss Hurth and Borg warner marine gears in our
- Tech Tip #2: Marine Transmission Fluid
- Tech Tip #47: Avoiding Idling Gears, An Interview in National Fisherman
- Tech Tip #51: Souping Up the Series 72 Borg Warner Gear
- Tech Tip #59: ZF/Hurth Marine Coupler or Damper Plate 101
- Tech Tip #101: Hurth Gear Shift Position: A Warning
- Tech Tip #105: Hurth and ZF/ Hurth Marine Transmissions: Old Wine in New Bottles?
Damper plates lead a tough life
They work in the dark, are often soaked in salt water, and are never checked, let alone maintained. They are the marine equivalent of a mushroom! The damper plate is bolted to the flywheel with a half dozen or so small metric allen bolts. Into this clutch like plate slides the splined input shaft of the Hurth or Borgwarner gear. The damper plate acts as coupler between the engine and the transmission and all torque is transmitted through it.
Noisy damper plate
Sometimes these hard working clutches rebel and their springs loosen up and even fall out. Or one or more of the allen bolts back out and the plate become loose and moves around. Symptoms of this will be a rattling sound from the bellhousing area when in neutral. Engaging gear is often difficult and the Hurth gear is hard to shift. Often loose or missing springs is the only problem. People often think that they need a new transmission when all they need is to replace the damper plate.
What to look for
If you suspect that your damper plate springs are loose and rattling around and that you have damper plate problems here is what to look for. First check your linkage to ensure that everything is tight and working properly. Then check that the bolts holding the damper plate in place are present and installed correctly. Verify that the Hurth or Borgwarner gear is not mis-aligned. Use a dial indicator to check for this. Finally, if the damper plate is worn and/or springs are missing, check to see that your Hurth or Borgwarner gear’s front bearing hasn’t failed. Worn damper plates can often cause the transmissions’ input shaft to wear and result in front bearing failure.
If your damper plate is worn, not to worry. We stock damper plates for most applications and have them ready for same day shipment anywhere in the world. We also have ZF/Hurth and Borgwarner Workshop Manuals and our Foley Hurth Hytork Fluid that we can send. As you can see, if you own a Hurth or a Borgwarner, we’ve got you covered!