1969 Imperial progress thread

[detmatt]

If the stub isn’t out of square I would just order the new bars a 1/4” shorter and run with it.

 

[vdk2010]

I agree! I just asked Firmfeel if it's too late the order the torsion bars a 1/4 shorter then the stock 50".
I hope that's still possible.

Nonetheless, I'm going to make some new isolators. Since all models except the Imperial doesn't even have these Isolators, I'm fine with stiffening them up.

 

[detmatt]

If those rubber isolators are good I’d leave them. It’s an Imperial for crying out loud! I’m serious.

 

[vdk2010]

If those rubber isolators are good I’d leave them. It’s an Imperial for crying out loud! I’m serious.

Oh, you're gonna hate some of my future decisions

But, initially, my plan was to reuse the original isolators, but after further inspection, they are not as good as I thought they are.

The rubber has cracks and got pretty soft over the years, they are not evenly high and they are deformed.

 

[detmatt]

These folks will refurb your original.
Nors Vulcanized Motor Mounts & Rubber Products | Then and Now Automotive

 

[Big_John]

These folks will refurb your original.
Nors Vulcanized Motor Mounts & Rubber Products | Then and Now Automotive

I've done business with them... I think they were specializing in old Mopar trucks for a while and overlapped into other parts. They seemed to be in flux at the time but I think they were Roberts Motor parts.

I'm in agreement to refurb the parts. I think that is most of your issue.

I also would not spend the money on new torsion bars... But that's me. The Firm Feel stuff is just made to stiffen the ride and it's an Imperial... It's supposed to ride soft. Unless the old bars are banged up or broken I would reuse them without hesitation. In fact, I'll even say that the 50 year old bars are probably as good as the new ones.

To make up the difference (if any after the refurb), I would shim the isolators back a little. I think you have some "stack up", as we used to call it, of tolerances that are affecting it, but most of the issue looks to me to be in the isolators.

 

[vdk2010]

I've done business with them... I think they were specializing in old Mopar trucks for a while and overlapped into other parts. They seemed to be in flux at the time but I think they were Roberts Motor parts.

I'm in agreement to refurb the parts. I think that is most of your issue.

I also would not spend the money on new torsion bars... But that's me. The Firm Feel stuff is just made to stiffen the ride and it's an Imperial... It's supposed to ride soft. Unless the old bars are banged up or broken I would reuse them without hesitation. In fact, I'll even say that the 50 year old bars are probably as good as the new ones.

To make up the difference (if any after the refurb), I would shim the isolators back a little. I think you have some "stack up", as we used to call it, of tolerances that are affecting it, but most of the issue looks to me to be in the isolators.

My original Torsion Bars are heavily pitted, I don't feel comfortable reusing them. I talked to a spring specialist of a spring manufacturer here in Germany. In a nutshell, he told me that springs can lose up to 70% of their rigidity due to heavy rust pitting because they loose their surface tension.
I don't know how much truth and how much marketing there is in this statement, but it concerned me enough to order new torsion bars. The other point is that the left torsion bar is bent.
I'm so deep into this project that a set of new torsion bars don't set me back by much anyway ;)

And I don't think they are much stiffer. They have the same diameter as the stock ones.

 

[Big_John]

My original Torsion Bars are heavily pitted, I don't feel comfortable reusing them. I talked to a spring specialist of a spring manufacturer here in Germany. In a nutshell, he told me that springs can lose up to 70% of their rigidity due to heavy rust pitting because they loose their surface tension.
I don't know how much truth and how much marketing there is in this statement, but it concerned me enough to order new torsion bars. The other point is that the left torsion bar is bent.
I'm so deep into this project that a set of new torsion bars don't set me back by much anyway ;)

And I don't think they are much stiffer. They have the same diameter as the stock ones.

I will 100% agree with the spring mfg.

But the "bent t-bar" catches my eye.

They don't bend unless some outside force bends them. That may be the source of your problem. Whatever bent the bar pulled things out of alignment.

 

[vdk2010]

I will 100% agree with the spring mfg.

But the "bent t-bar" catches my eye.

They don't bend unless some outside force bends them. That may be the source of your problem. Whatever bent the bar pulled things out of alignment.

The Sway bar mount was broken off on the lower control arm on the driver side where the torsion bar is bent. Maybe the previous owner hit something with the LCA!?

 

[70bigblockdodge]

The Sway bar mount was broken off on the lower control arm on the driver side where the torsion bar is bent. Maybe the previous owner hit something with the LCA!?
View attachment 476196

Tow truck driver. I put them up with police officers, don't ever want to deal with one again in my life, or only making your life worse in the long run.

 

[saforwardlook]

I can only expand on John's comments a little bit by saying that after all the detail you have suffered through, I can not understand why you would want to add new stiffer rubber mounts to your Imperial. The mystique of an Imperial is that the 69 and up models exude a ride quality and quiteness, while maintaining good control as well, that is unmatched in any other vehicles of this era. No New Yorker or Cadillac or Lincoln had the perfect balance that Imperial did. Unless you never plan to drive the car because it is so perfect, carrying out this plan would be unfortuante at best.

To change the mounts/isolaters to anything that varies at all would totally ruin your otherwise brilliant restoration efforts. I truly believe to make such a move would be a catastrophe - I am serious!!

 

[Big_John]

I've done business with them... I think they were specializing in old Mopar trucks for a while and overlapped into other parts. They seemed to be in flux at the time but I think they were Roberts Motor parts.

I'll walk that comment back. I was confusing the two, although Roberts may be selling Then and Now's products. Similarity in the location, website and product. Roberts is still in business.

Sorry for any confusion... No sleep last night.

 

[Big_John]

Tow truck driver.

A likely culprit, but more likely it was a buddy with a 4WD pulling it out of a ditch.

My '73 NYB had the front frame, were the brake struts fasten, torn away by that type of abuse from a PO.

 

[vdk2010]

You got me wrong. My ultimate plan is not to stiffen up the entire Imperial. I would use stiffer mounts if that's the only reasonable solution I have, but if there is a affordable solution to get original rubber mounts, I'll try that first, obviously.
What Then and Now Automotive does looks pretty awesome, but also pretty expensive with building a special high pressure mold and all that. I asked them for a quote, so we will see.

On the other hand, building poly urethane mounts with a relatively low shore hardness isn't that bad either. It's not like these "performance bushings" you can buy for modern cars..!
My new K-Member bushings are poly urethane as well and they are as flexible as the original rubber!

 

[detmatt]

I had them do the mounts in my silver car about 6 or 7 years ago and it cost me about $260.

 

[commando1]

Sadly, I never had an Imp.
Fortunately, I never had a Imp.

You guys are true enthusiasts!

 

[Big_John]

On the other hand, building poly urethane mounts with a relatively low shore hardness isn't that bad either. It's not like these "performance bushings" you can buy for modern cars..!
My new K-Member bushings are poly urethane as well and they are as flexible as the original rubber!

Thinking about it, that may really be a good solution.

At first blush, having the rubber mounts rebuilt sounds good, but my questions would be if they could really duplicate the rubber used by the OEM in building the mount. They are using a best guess with hand poured/mixed compounds. That "best guess" should be better than the old rubber, I think that would be a given, but would it be as good as it was when it was new? When I look at repop rubber items, I always see blocks of rubber and when I see OEM rubber, I see tapers, internal cavities etc.. So there's that aspect of how the rubber behaves... along with the durometer and durability.

Going to a "soft" polyurethane could be just as good. If you don't get it right, you can redo it in another poly or modify the design.

I would be torn... (bad pun not intended)

 

[saforwardlook]

You got me wrong. My ultimate plan is not to stiffen up the entire Imperial. I would use stiffer mounts if that's the only reasonable solution I have, but if there is a affordable solution to get original rubber mounts, I'll try that first, obviously.
What Then and Now Automotive does looks pretty awesome, but also pretty expensive with building a special high pressure mold and all that. I asked them for a quote, so we will see.

On the other hand, building poly urethane mounts with a relatively low shore hardness isn't that bad either. It's not like these "performance bushings" you can buy for modern cars..!
My new K-Member bushings are poly urethane as well and they are as flexible as the original rubber!

If you were referring to comments about using polyurethane to make the mounts, you said "Oh, you're gonna hate some of my future decisions " in response to Matt's input above.

Every time I used poly urethane anything it made the car miserable to drive because it absorbed nothing.

 

[Big_John]

Every time I used poly urethane anything it made the car miserable to drive because it absorbed nothing.

I think if the urethane was the correct durometer, it might be a good choice. Not knowing what the OEM spec'd, I think even redoing with rubber is a shot in the dark.

From what I've read, the urethane bushings that people buy for "improving" (note quotes) suspension is from 90A to about 70D. Here's a chart for reference. Cast Urethane Hardness Chart - Urethane Physical Proper | Precision Urethane

For reference a hockey puck is 90A (90 on the Shore A scale) and they are harder than the rubber I've seen in any bushings I've seen used in on engine mounts etc., based on my edumacted fingernail imprint test. A shoe heel is 70A according to the chart and that's probably closer to what we see used.

So, the right urethane just might work... Gotta stay on the low end of the scale and make sure there's enough strength.

 

[bigmoparjeff]

I suspect that the softer urethanes have durability issues.

When VTA redid the drivetrain in my bus, they installed aftermarket urethane engine mounts, and the mounts ended up failing in less than 15K miles. They were a much softer material than you typically find with the aftermarket suspension bushings.

Jeff