1956 T Bird-The old balancer had serious groves, so I got a new old stock part. There is a ridge in the bore of both the old and new part. In trying to install the new part we "bottom out" in less than an inch. We just get in to where the key restricts the turning of the damper. When the damper stops, it sounds like we bottom out on solid steel?! We tried without the key to no avail. Any thoughts or suggestions would be greatly appreciated! Thanks in advance.

Welcome to the site fifty6tbird.  There are a number of 'Bird owners on this Forum.

The grooves in your original crankshaft damper & pulley assembly are likely caused by the two neoprene lips of the front seal in the engine timing chain cover.  It's amazing that a neoprene seal can do that!  There is a repair sleeve available that will repair the worn surface of your damper.  It is an interference fit and is installed manually with a hammer.  Auto parts stores stock them...

I've been told that several Thunderbird parts suppliers are selling reproduction crankshaft damper / pulley units.  Check to see if what you've got is a N.O.S. unit or an aftermarket reproduction replacement piece.  Look for the following on what you obtained...

• Do you see two hard-to-distinguish stylized FoMoCo script logos present in ellipses inside of a recessed rectangle (1 1/2 x 11/16 inch), 180 degrees apart on the back side of the donut weight?
• Do you also see two recessed rectangles with radius-ed ends measuring  1/4 x 1 1/4 inch long, 180 degrees apart and at 90 degrees to the FoMoCo script logos with the recessed part number ECJ631xB (the letters and numbers are hard to read, the 'x' I've indicated is impossible on mine, looks like a 5 or perhaps a 6...)
• Does the neoprene rubber seal that secures the donut have the identification markings B-126590  S.C. CO. showing on the perimeter edge on the back side of the donut
• Is the slightly larger bore surface at the chamfered mounting end approximately 1 3/16 inches in length?
  

NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

After sleeping on your question...  As you mentioned, there is a difference in the damper opening diameter some 1+ inches in as you install it.  That counterbore has no chamfer where the diameter changes.  I'm suspicious that with the weight of the 'Bird damper unit you've got to deliberately lift the nose of the damper to get it to step-up into the second diameter.  I know that the difference between the two bores seems very slight, but I think that's why you're hitting the dead end-stop as you go to slide it on the nose of the crankshaft.

Also, the fit of the damper on the crank nose, by design, is tight.  I've never had to do it myself, but it might go on more easily if you warm the snout of the damper with a hair dryer to make it slip on more easily.  Yeah, I'm serious.  

Hope this helps.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Even with the car and truck dampers, you need to kinda lift and wiggle a bit to make sure it is on the snout properly.  Ultimately, you need a damper installer to complete the job.  You should use some grease or anti-seize on the snout to help ease the installation.

Since the old one came out, and appears to be identical dimensionally to the NOS damper, we know that there should be no problem with the damper and nothing beyond the timing cover preventing the installation.

Like Charlie suggests, it is probably just that step in the damper that you are hitting.  You will need an installer to complete the job.  


Lawrenceville, GA

Fifthy6tbird;
Just to follow-up on what both Charlie's have said; To smooth out the seal to balancer area ask for a "speedy sleeve" at your parts store. They will likely also have the harmonic balancer installation/removal tool. They are not that expensive and worth their weight in gold! Welcome to the site!
Rono

  Ron Lane,  Meridian, ID

Hello 56,
To add to this I have the 57 bird same damper, mine can  barely get started by hand, I sent away to CASCO for the removal and install tools they sell, fair price and they work great with a little oil. Curious as to how you removed yours?

Gary