Ooops, I meant to say 57 or later DISTRIBUTOR, not tach!  I,m 64, so I have an excuse. 

Bud in Northern Arizona on route 66 in Winslow (standin' on the corner)

If you're American, buy American

631/2 Galaxie 500XL 406   55 T-Bird

Rod,

Why don't you just borrow someone's 57 or later tach to see if it solves your problem. I assure you it is not too short as I have a Blue Thunder intake on my 55 Bird with a non tach driven dizzy (57 or later). I bought a Mooneyes 3 3/8" 0-6000 rpm tach to replace my old gear driven one. I had to modify it slightly to fit in the T-Birb bezel but it looks like it was made for the Bird. It is made by Classic Instruments.

With a little recurve on the stock dizzy, and a Pertronix installed, it works perfectly

Bud in Northern Arizona on route 66 in Winslow (standin' on the corner)

If you're American, buy American

631/2 Galaxie 500XL 406   55 T-Bird

Rod:

The tach gear is pinned to the same shaft as the drive gear and has nothing at all to do with the advance mechanism or the points mounting plate.  It only drives the tach.  Some large trucks in the '60s had tachometers but their scale only went to about 3500 rpm.

John - "The Hoosier Hurricane"

Everyone I have seen is like that as well.  I was surprised when I would hold onto the gear end I was getting movement at the top.  Now what I do not know is if this particular dist is actually made of more than one shaft because of the mechanical tach that is located about 4" down from the end of the rotor end.  The tach actually attaches to the side of the dist.  Do any other Fords have this?  My 60' ford with a 292 does not.

Hope to hear something from Midtown Service today.  Hopefully a simple fix.  Missing all this great Missouri summer weather to drive it and it is just not the same thing driving in a Saturn! ~Rod

1957 Thunderbird

312

I would have totally agreed with you except when they would close, I woudl try to move the unit with my hand, just to check for this, and the dumb things were tight as can be.  I do think there is a problem in the plate itself.  It seems to have some unusual movement in it.  Since this plate looks so much different than other plates I have seen, I am just not sure it is to move like this or not.  My initial guess is it should only move back and forth to allow for the vacuum advance.  Thanks for your help.  I will pass this onto Midtown Service.

Rod

1957 Thunderbird

312

I checked this by removing the plate and then attaching the points and condensor.  The plate on this particular car is almost 1/4" thick and there is no screw that protrudes far enough down to touch anything.  At least I did not think so.  I will pass this onto Terry's Midtown Service in Fort Collins. ~ thanks

1957 Thunderbird

312

Being in Colorado is undoubtedly the problem, no question. The rotor is SUPPOSED to move in relation to the shaft. It is two pieces, controlled by the weight and spring mechanism known as the mechanical advance. This moves the rotor ahead when the engine RPM inceases, which advances when the plug fires. This is because as the engine speeds up, there is less time for the mixture to fire, so they light the fire earlier in the cycle.

Frank/Rebop

Bristol, In ( by Elkhart) 

Doyou have a screw that is too long in the distributer so that it bottoms out and feels tight but is not really holdin the points tight to the plate. Seems like if there was that much slop in the shaft it wold be easy to pick up on.

When you hear hoofbeats you look for horses before you look for zebras.

That is your mechanical advance working. You have three advances on a regular distributor. The initial advance you check with a timing light, the mechanical advance and the vacuum advance. I have read this post and really believe there is something wrong with the bolts/screws that hold your points in place. That is the only thing that will allow them to change gap at the rate you state.

Ol'ford nutCentral Iowa

56 Vic w/292 & 4 spd.

RB~ That is a possible option. 

I picked the dist. up form the mechanic yesterday and I could hold onto the gear end and still rotate the rotor a good 10 degrees.  Now this one has the mechanical tach inside it so I guess it is possible there are actually 2 parts to the shaft but I always thought it was one long shaft.  Shows what I know.

Anyone have an exploded view of a 57' Bird 312 Dist? 

Will be in Colorado tomorrow.  Hopefully that is all the problem is.

R

1957 Thunderbird

312