The tale of 3 GT500 dampers

[shelbydoug]

Here's a pic of mine off the car. It's like it's been machined with a notch.

Explain to me how the engineering works where this isn't caused by the edge of the balancer cutting itself in and is caused by the flat of the balancer? That makes no sense what so ever?

How thick is the shim/spacer on the 68 GT500 from the factory? I presume that "Ford" noticed these anti-sway bar issues on the '67 GT500 and offered them as a quick, inexpensive solution?

This bar is original to the car but I'm questioning the safety of running it?

[The Going Thing]

Hello, Doug. The spacer was used on the 68 model year. My assumption would be that the change in diameter from the all cast iron pulley/damper to a large diameter harmonic balancer necessitated the change/modification. Because my damper was wiped where the timing marks are about midway I had spoken to Arnold Marks at Mustangs Etc who told me about the spacers used on the 428CJ to eliminate this exact issue. I bought the set he had.  They are reproduced and offered via NPD these days.

[Bob Gaines]

Here's a pic of mine off the car. It's like it's been machined with a notch.

Explain to me how the engineering works where this isn't caused by the edge of the balancer cutting itself in and is caused by the flat of the balancer? That makes no sense what so ever?

How thick is the shim/spacer on the 68 GT500 from the factory? I presume that "Ford" noticed these anti-sway bar issues on the '67 GT500 and offered them as a quick, inexpensive solution?

This bar is original to the car but I'm questioning the safety of running it?

I am not saying that it couldn't but have never heard of a sway bar snapping because of the notch. The 68 CJ spacers were the quick fix.they were only used in 68 . I know this has never been brought up before but the permanent fix was the redesign of the swaybar for 69/70. The 69/70  swaybar was a service replacement for the 67/68. The subtle contour difference is hard to distinguish unless you know where to look  (sway bar bracket area) and even then it still can be missed . Many are not aware their swaybar has been changed. There are many more of the 69/70 version in circulation because of more applications using them compared to the relatively rare 67/68  competition suspension version. I will post a picture of the difference when I get to my files if someone doesn't show my old picture first.

[shelbydoug]

Here's a pic of mine off the car. It's like it's been machined with a notch.

Explain to me how the engineering works where this isn't caused by the edge of the balancer cutting itself in and is caused by the flat of the balancer? That makes no sense what so ever?

How thick is the shim/spacer on the 68 GT500 from the factory? I presume that "Ford" noticed these anti-sway bar issues on the '67 GT500 and offered them as a quick, inexpensive solution?

This bar is original to the car but I'm questioning the safety of running it?

I am not saying that it couldn't but have never heard of a sway bar snapping because of the notch. The 68 CJ spacers were the quick fix.they were only used in 68 . I know this has never been brought up before but the permanent fix was the redesign of the swaybar for 69/70. The 69/70  swaybar was a service replacement for the 67/68. The subtle contour difference is hard to distinguish unless you know where to look  (sway bar bracket area) and even then it still can be missed . Many are not aware their swaybar has been changed. There are many more of the 69/70 version in circulation because of more applications using them compared to the relatively rare 67/68  competition suspension version. I will post a picture of the difference when I get to my files if someone doesn't show my old picture first.

Probably any aftermarket bar will do. I don't have a '69 production bar to compare it to but do have a '68 bar.

The thickness of the shims still has not been stated. Another 1/2 answer I suppose?

Personally, I'd prefer to keep the original bar with the car. It just adds to mystique of the marque.


I'll have to let the suspension hang, and go measure and cypher a solution. Normally, being from NY, I'd say calculate but I want to stay in context.

What the heck is a cypher anyway? Is it some kind of a venereal infection?



Since the suspension hangs at a different level depending on the shocks, I'd presume that the interference happens with the Ford shocks, not the Koni's and probably when they are worn in a little? Any confirmation on that? Hum?

The shop manual pictured suspension supports I think will not be necessary for this?

I'm still waiting for a tank of original air to come up for the tires.


So I'm trying to remind myself what the point of this discussion was? I don't know...first base! Hum? Exactly! 

[pbf777]

     This is an interesting topic, as it challenges us, decades post the original production to attempt to determine the intent for a component modification by Ford. 

     First I assume that no one here apparently is either a first hand witness, nor holds any documentation or is aware that any currently exists describing the reasoning, so we are all speculating?

     If so, I am a little at a loss to actually believe that the real engineers at Ford, after concluding that there was interference between the damper's' outer diameter and the sway bar would choose to bevel the edges of the damper solely as to avoid a perhaps more aggressive notch from being formed from the corner edge of the damper into the sway bar, but still permitting this interference otherwise?  If one considers the impact (pun intended) of this event upon the components directly involved, and the resultant effect upon others even if only indirectly, then I say: no way!           

     As far as a secondary bevel to the rear of the inertia ring perhaps for the purpose of balance, I don't feel there is any credence in this, as a symmetrical material removal at the face would not cause a change or imbalance of the component (as relevant here), therefor a like removal at the rear has no purpose in this arena.  But what is accomplished, and I believe the intention, in the change (reduction in this case) of the inertia ring mass is a change of the harmonic vibration dampening effect, or "tuning" of the damper for the 428 P.I. engine requirements versus the 427 application from which the dampers' engineering originated, and such a change otherwise I believe would not have been approved by those responsible for such, with other simpler solutions for chassis fitment purposes available.           

     The sway bar spacers and change of the profile of the bar both appear to be a response to the apparently overlooked issue of the interference, and it is feasibly reasonable to me to believe that this issue was just that, and that the dampers' profile change had nothing to do, nor was intended to address this interference, as it was ineffectual for such.

     Well, I wasn't there, and my ears are not deaf to other's, but that's my speculation on the matter, for whatever it may be worth.           

     Scott.

     

[Bob Gaines]

Here's a pic of mine off the car. It's like it's been machined with a notch.

Explain to me how the engineering works where this isn't caused by the edge of the balancer cutting itself in and is caused by the flat of the balancer? That makes no sense what so ever?

How thick is the shim/spacer on the 68 GT500 from the factory? I presume that "Ford" noticed these anti-sway bar issues on the '67 GT500 and offered them as a quick, inexpensive solution?

This bar is original to the car but I'm questioning the safety of running it?

I am not saying that it couldn't but have never heard of a sway bar snapping because of the notch. The 68 CJ spacers were the quick fix.they were only used in 68 . I know this has never been brought up before but the permanent fix was the redesign of the swaybar for 69/70. The 69/70  swaybar was a service replacement for the 67/68. The subtle contour difference is hard to distinguish unless you know where to look  (sway bar bracket area) and even then it still can be missed . Many are not aware their swaybar has been changed. There are many more of the 69/70 version in circulation because of more applications using them compared to the relatively rare 67/68  competition suspension version. I will post a picture of the difference when I get to my files if someone doesn't show my old picture first.

Probably any aftermarket bar will do. I don't have a '69 production bar to compare it to but do have a '68 bar.

The thickness of the shims still has not been stated. Another 1/2 answer I suppose?

Personally, I'd prefer to keep the original bar with the car. It just adds to mystique of the marque.


I'll have to let the suspension hang, and go measure and cypher a solution. Normally, being from NY, I'd say calculate but I want to stay in context.

What the heck is a cypher anyway? Is it some kind of a venereal infection?



Since the suspension hangs at a different level depending on the shocks, I'd presume that the interference happens with the Ford shocks, not the Koni's and probably when they are worn in a little? Any confirmation on that? Hum?

The shop manual pictured suspension supports I think will not be necessary for this?

I'm still waiting for a tank of original air to come up for the tires.


So I'm trying to remind myself what the point of this discussion was? I don't know...first base! Hum? Exactly! 

I am not sure if different shocks will have a effect or not given the travel most likely is the same . Given the spacers were designed  around the 68 smaller diameter balancer it would probably be prudent to go ahead and take measurement for spacers with your larger diameter C6AE balancer. I would like to point out that many problems with sway bar contact are caused by using the MPC called for 65-67 regular Mustang end link kit. The 67 competition suspension used a different end link kit regardless of GT350 or GT500. Not going into detail nuance differences in hardware (which there are)it is basically the same endlink kit used on 68-70 Mustang.This can be substituted successfully and fine for all but concours considerations. The bolts and the tube are longer . The regular 67 Mustang tube is shorter. The longer tube tilts the bar down more giving additional clearance. With the wrong end links you make the problem under spirited driving over bumps and jumps even worse!! The correct end links are not enough for the Spirited bumps and jumps but the point is that you need the correct end link before taking measurements to confirm spacers for adequate clearance . If you already have the longer endlinks (sorry I know them by sight but don't have tube measurements at the moment) then proceed to taking spacer measurements. 

[shelbydoug]

I think they knew there was contact and the balancer would just spin around a little on the bar. I don't think they realized it would polish off the timing marks?


The other alternative is that they did the bevels for esthetics? Want to bet on that one?


This is one of the old managerial procedures that it only required 15 minutes of analasis. 30 minutes is too long. Put the car in production and fix it in service.

After all, the bar only hits when the front suspension is hanging. You are supposed to use the supports shown in the shop manual if it is on the lift and how air born is a driver likely to get?

The simplest answer is shim the bar until it clears?

[Bob Gaines]

     This is an interesting topic, as it challenges us, decades post the original production to attempt to determine the intent for a component modification by Ford. 

     First I assume that no one here apparently is either a first hand witness, nor holds any documentation or is aware that any currently exists describing the reasoning, so we are all speculating?

     If so, I am a little at a loss to actually believe that the real engineers at Ford, after concluding that there was interference between the damper's' outer diameter and the sway bar would choose to bevel the edges of the damper solely as to avoid a perhaps more aggressive notch from being formed from the corner edge of the damper into the sway bar, but still permitting this interference otherwise?  If one considers the impact (pun intended) of this event upon the components directly involved, and the resultant effect upon others even if only indirectly, then I say: no way!           

     As far as a secondary bevel to the rear of the inertia ring perhaps for the purpose of balance, I don't feel there is any credence in this, as a symmetrical material removal at the face would not cause a change or imbalance of the component (as relevant here), therefor a like removal at the rear has no purpose in this arena.  But what is accomplished, and I believe the intention, in the change (reduction in this case) of the inertia ring mass is a change of the harmonic vibration dampening effect, or "tuning" of the damper for the 428 P.I. engine requirements versus the 427 application from which the dampers' engineering originated, and such a change otherwise I believe would not have been approved by those responsible for such, with other simpler solutions for chassis fitment purposes available.           

     The sway bar spacers and change of the profile of the bar both appear to be a response to the apparently overlooked issue of the interference, and it is feasibly reasonable to me to believe that this issue was just that, and that the dampers' profile change had nothing to do, nor was intended to address this interference, as it was ineffectual for such.

     Well, I wasn't there, and my ears are not deaf to other's, but that's my speculation on the matter, for whatever it may be worth.           

     Scott.

   

Of course you are welcome to your opinion . I would like to point out that the other 427 balancers were straight cut and only the C6AE was beveled. What more reasonable explanation for the bevel then? Given the clearance issue being discussed I think that the  OCCAM'S Razor principle of the simplest reason tends to be the most correct or as another more modern Logician our own Special Ed Meyer says "That's just the way it is" .

[shelbydoug]

     This is an interesting topic, as it challenges us, decades post the original production to attempt to determine the intent for a component modification by Ford. 

     First I assume that no one here apparently is either a first hand witness, nor holds any documentation or is aware that any currently exists describing the reasoning, so we are all speculating?

     If so, I am a little at a loss to actually believe that the real engineers at Ford, after concluding that there was interference between the damper's' outer diameter and the sway bar would choose to bevel the edges of the damper solely as to avoid a perhaps more aggressive notch from being formed from the corner edge of the damper into the sway bar, but still permitting this interference otherwise?  If one considers the impact (pun intended) of this event upon the components directly involved, and the resultant effect upon others even if only indirectly, then I say: no way!           

     As far as a secondary bevel to the rear of the inertia ring perhaps for the purpose of balance, I don't feel there is any credence in this, as a symmetrical material removal at the face would not cause a change or imbalance of the component (as relevant here), therefor a like removal at the rear has no purpose in this arena.  But what is accomplished, and I believe the intention, in the change (reduction in this case) of the inertia ring mass is a change of the harmonic vibration dampening effect, or "tuning" of the damper for the 428 P.I. engine requirements versus the 427 application from which the dampers' engineering originated, and such a change otherwise I believe would not have been approved by those responsible for such, with other simpler solutions for chassis fitment purposes available.           

     The sway bar spacers and change of the profile of the bar both appear to be a response to the apparently overlooked issue of the interference, and it is feasibly reasonable to me to believe that this issue was just that, and that the dampers' profile change had nothing to do, nor was intended to address this interference, as it was ineffectual for such.

     Well, I wasn't there, and my ears are not deaf to other's, but that's my speculation on the matter, for whatever it may be worth.           

     Scott.

   

Of course you are welcome to your opinion . I would like to point out that the other 427 balancers were straight cut and only the C6AE was beveled. What more reasonable explanation for the bevel then? Given the clearance issue being discussed I think that the  OCCAM'S Razor principle of the simplest reason tends to be the most correct or as another more modern Logician our own Special Ed Meyer says "That's just the way it is" .

I see the brilliance in his statement. I stand enlightened.

[gt350hr]

   The spacers on my 68.5 CJ are 1/4" . The spacer has no affect other than increasing bar to dampner clearance. The same thing "could" have been done with a longer link BUT that "can" (or could) get the bar too close to other things under compression. Changing the "bar angle" has no effect of bar function.
    "I" don't see a functional reason for the bevel in the rear but at Ford "everything had a reason" or it would not have been changed. Changes were NOT random nor dome without a blueprint change. I do not have much of the XE information and the only way to solve the mystery is look at the blueprint for the dampner.
    Randy

[The Going Thing]

Randy: I wasn't discounting it either. I was just noting where mine was damaged and several sold on Ebay in recent history.

[shelbydoug]

   The spacers on my 68.5 CJ are 1/4" . The spacer has no affect other than increasing bar to dampner clearance. The same thing "could" have been done with a longer link BUT that "can" (or could) get the bar too close to other things under compression. Changing the "bar angle" has no effect of bar function.
    "I" don't see a functional reason for the bevel in the rear but at Ford "everything had a reason" or it would not have been changed. Changes were NOT random nor dome without a blueprint change. I do not have much of the XE information and the only way to solve the mystery is look at the blueprint for the dampner.
    Randy

TY Randy. Now the secret is out of the bag.

FYI, I went to 6" x 1/2" od bolts on the '68 end links. The stock bolts were bending up.

[JWH]

This is a timely topic as I am just dropping the 428 into my '67 GT500. I have noticed that the balancer sits right on top of the sway bar and I have wondered how to solve for this issue. From this thread, I read there are three solutions:

1) install the spacers for the sway bar
2) install the longer hardware links for the sway bar
3) install a '69-'70 sway bar with a slightly different shape

Of these three, which is most effective to make sure the balancer and sway bar never make contact?

Will just one of these solutions solve the problem or is a combination the best way to go? For instance, install both the spacers and the longer links?   

Thanks in advance.
Jeff

[shelbydoug]

This is a timely topic as I am just dropping the 428 into my '67 GT500. I have noticed that the balancer sits right on top of the sway bar and I have wondered how to solve for this issue. From this thread, I read there are three solutions:

1) install the spacers for the sway bar
2) install the longer hardware links for the sway bar
3) install a '69-'70 sway bar with a slightly different shape

Of these three, which is most effective to make sure the balancer and sway bar never make contact?

Will just one of these solutions solve the problem or is a combination the best way to go? For instance, install both the spacers and the longer links?   

Thanks in advance.
Jeff

They can all be part of the solution but I think, the simplest and safest solution is just to shim the bar down.

You can play with the end links but from what I see, they do not solve the problem.

Others who have worked on this will likely have different perspectives.

[The Going Thing]

There is a real easy fix for it. Buy the aftermarket 1" sway bar, put your original away.  If you do order one, be sure to make sure it's for an FE car. The small-block units also don't clear oil filter on an FE either. 
As for the sharp edge. If you had a 67 500 you'd know the OE 15/16 bar is nowhere near either edge of the damper. The rub is almost dead-center on the damper.
I am still inclined to believe that it was done for tooling purposes. Rolling the timing marks on the damper. The earlier 427 damper doesn't have any degree/timing marks. It simply has a V notch on the front edge of the incorporated pulley, which necessitates a timing pointer with the degree mark on it.