bertram31.com

does anyone know the appox cost of new damper plates
zf trans

Charlie,
Replaced mine last year when I had a Twin Disc gear rebuilt. I think it was in the low to mid two hundreds for the part. Transmission guy advised that flat idle with with the four cylinder Yanmars was deadly to this part. Increasing the idle underway by a hundred or so RPM's will vastly increase the life. Something about surge and vibration.
Harry

thanks harry

I was told to use the Vulcan Torflex damper for the 4LHA to ZF 63a on my install. 7 years and nearly 1000 hours and still quiet at idle speed. Not sure what part number or what I paid though. I'm sure Bruce would know the details.

Eddy G.

There was a service bulletin in 04 on the drive plates and upgrading. If I remember those vulcan plates are about $400 and up.

Nobody will admit it(of course) but depending on your prop, shaft length and a bunch of other variables it was very possible to set up torsional issues that ate non driving gear clutch plates and ZF after 04 I believe was building gears with beefier plates to prevent this.

Apparently the early drive plates took the abuse instead of the gear and particularly the stb side was noisy. The upgraded drive plates took the problem and transferred it to the gears possibly although no one ever admits anything due to liability issues.

Before I would upgrade my drive plate and I owned a ZF gear I would call ZF with a serial number to find out what you have and if there would be a possible gear issue.

There really is a lot of science behind strapping a flexible shaft, prop, inducing angles, variable drag coefficients and other neat pocket protector science stuff behind an engine and spinning it 1 to 2 krpms.

thanks bruce and ed
ill past this info on to the yard

I'm going to share this with my guys too.

I have Vulcan drive plates along with steel instead of alluminum sae adapters. No rattles,no shakes,no vibrations or rattling noice however when they are in there in! They grab instantly so the boat will jump into gear mainly with more torque from 6 cylinder. They are available directly from ZF in RI.