I am wondering if I should have my dampener rebuilt or replaced on my 56 Mercury Montclair 312. Anyone have an opinion of whether to rebuild or get a new manufactured one? I have already contacted the Damper Dudes, they said they can rebuild mine, they did not have one on the shelf so rebuild is my only option from them. I see "new" ones, made in Mexico, but I am wondering if keeping mine would be the better option. Mine shows no sign of slipping, no wobbling, but it is a 1956 and I have no way of knowing if it has ever been rebuilt. Should I leave it alone or is it worth the time/money to address it now? If the original ones are barely adequate, should I replace it with a better one?  The car is not driving daily, it is just a weekend driver for a few months a year due to our beautiful Minnesota winters.
All info is appreciated.

Fortunately, for you, it's not a Tbird damper. Having said that, you do have more options. If your engine will remain stock, runs well, and there's no sign of damper issues, I would leave it alone. If you still have concerns, or you intend to rebuild the engine in the not-too-distant future, go ahead and send the damper to Damper Dudes. Ted Eaton recommended them, and I sent my 55 Tbird damper to them. They have a fast turnaround and will use cheapest return shipping, unless you request otherwise. 

Note: The timing marks are very hard to see and should be located on the outer edge of the pulley (they are on my Tbird damper). 

I’m in California and mine was back to me in three days from Damper Dude. They did not remake the tdc line but I edge filed it deeper and added additional lines I could see at 5-10-15-20-25-30-35-40* with a protractor that way I could see total advance.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

If it’s any consolation, the harmonic damper on my ’55 Customline is still the original and has never been rebuilt.  With over 300K miles on the engine now, that damper has held up well.  No oil leakage at all though so that has a lot to do with the damper holding up like it has.

As the harmonic dampers age, the rubber elastometer holding the damper ring in place does get harder and increases the potential for the damper ring to slip.  I recently put together a Y using a NOS 3 belt damper and that damper ring slipped after just a few dyno pulls.  It was a three sheave damper so it was worth getting it rebuilt.  Had it been a one belt damper, a new replacement would have been considered.  That 3 groove damper was sent to Damper Dudes for the rebuild and it has held up well after being stressed on a 400HP Y.  Turnaround time for the rebuild was about 10 days including shipping.

The one part of your damper that may have you rebuilding it rather than replacing it with a new damper is the belt size.  Check your Mercury and see if it uses a ½” belt.  If so, then rebuilding the damper is a better option.  The new ‘Made in Mexico’ dampers use the 3/8” belt which are used on the ’57 and newer Y-Block engines.

Lorena, Texas (South of Waco)

On the Merc, the marks are on the ring, not the pulley.  TBird have the marks on the pulley





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Well, after the comments and some more research reading, I have decided that I will mark the ring/hub and keep an eye on it for any sign of slipping and leave it alone. Thanks for the info. I will have more questions....