1969 - 1971 C body Stub Frame (subframe)

[sevnt300]

Rigidity and strength is the exact reason. All A, B, C and E body convertibles have extra supports to try to make up for the lack of the roof support. I assume that 1970 wagons use the rigid mount for extra strength which obviously wasn't needed due to the 1971's being fitted with the TQ frames. There is extra bracing on the 69 - 70 C body convertible door pillars and windshield frame that work along with the rigidly mounted stub frame to keep the flex to as little as possible. Even though C bodies have a bolt on fore structure they are still unibody cars so the body integrity is very important especially on convertibles. The rocker panels, floor pan and closed doors are the only support from the door pillars to the rear body and frame components. The body flex is probably the reason why the Chrysler convertibles all came with door edge guards as standard equipment. I don't think the Torsion Quiet frame on John's car will break the car in half but it does separate the components that are supposed to work as one. As soon as I saw the picture of the TQ frame under that car I was just waiting for the accident story from the past. I wasn't trying to ruffle anyones feathers with this posting I just wanted to show people that they have options to get the correct parts.

It is also true that you can use later model torsion bars in the earlier cars with the added benefit of beefier bars than were available in earlier applications to keep the yachts from listing side to side.

Good Luck

 

[commando1]

Has anybody ever bolted a 74-78 stub frame to a 71-73 body?
ANY pre-74 body

 

[Big_John]

Interesting comment about the door edge guards... I haven't experienced perceivable body flex. The doors have always opened and closed and stayed in alignment etc and the car doesn't creak and groan. I used to get that when the targa top was off my C4 Corvette.

So... the frame isn't mounted "rigidly", but how much difference does it make in real life? Maybe the car would handle better or be more responsive to steering input... That's not high priority on a car like this. I'm not going to be autocrossing this big tank. There may be an advantage in the frame being longer and the mounting point being moved back over a foot and "soft" mounts on a short frame may not work well. Then again, I'm not an automotive engineer..

I've driven a lot of miles in other C-body cars, but frankly this is the first C-body vert I've owned so I have no point of reference. I'll tell you the car does drive very nicely and goes straight. What more do I want?

 

[sevnt300]

Nothing I said was intended as a putdown of your car. Every unibody convertible I have ever driven in, if you look at the gap between the door and quarter as you drive down the road, the gap opens and closes over bumps (sometimes quite a bit) which makes you think that every convertible should have a full frame instead of just adding supports to the unibody. Who knows what advantage or disadvantage the TQ frame has? There's certainly no reason to change the frame if your car has been fine for all these years since that accident.

Its Funny that you mention that the “bodywork we've uncovered has been pretty good for the most part and of that era in methods. It wasn't unusual to piece cars together back them”. The piece together part describes the quarter panel replacement on my car with a ’69 300 2dr sedan brazed over part of the original quarter so it ended up crooked, they obviously didn’t know the wheel well was different between a convertible and sedan or feel there was any reason to attach the bracing in the trunk so they just left it all dangling.

I only know that the Newport and 300 convertibles came with the factory door edge guards, I am not sure if it was standard on the Dodge and Plymouth convertible models.

 

[polara71]

Nothing I said was intended as a putdown of your car. Every unibody convertible I have ever driven in, if you look at the gap between the door and quarter as you drive down the road, the gap opens and closes over bumps (sometimes quite a bit)

How would anyone know that?

 

[ceebuddy]

It probably depends on where you sit and where you look at... :happy7:

 

[polara71]

Well that's what I was thinking.......


Put the efin windows down

 

[kmccabe56]

Rigidity and strength is the exact reason. All A, B, C and E body convertibles have extra supports to try to make up for the lack of the roof support. I assume that 1970 wagons use the rigid mount for extra strength which obviously wasn't needed due to the 1971's being fitted with the TQ frames. There is extra bracing on the 69 - 70 C body convertible door pillars and windshield frame that work along with the rigidly mounted stub frame to keep the flex to as little as possible. Even though C bodies have a bolt on fore structure they are still unibody cars so the body integrity is very important especially on convertibles. The rocker panels, floor pan and closed doors are the only support from the door pillars to the rear body and frame components. The body flex is probably the reason why the Chrysler convertibles all came with door edge guards as standard equipment. I don't think the Torsion Quiet frame on John's car will break the car in half but it does separate the components that are supposed to work as one. As soon as I saw the picture of the TQ frame under that car I was just waiting for the accident story from the past. I wasn't trying to ruffle anyones feathers with this posting I just wanted to show people that they have options to get the correct parts.

It is also true that you can use later model torsion bars in the earlier cars with the added benefit of beefier bars than were available in earlier applications to keep the yachts from listing side to side.

Good Luck

Edge guards being standard on convertibles is gonna make me have to look that up. I'm not calling you on it, but I'm not signing up to it either. Until I check.

 

[commando1]

Can not see how door edge guards will prevent anything.

 

[Big_John]

Nothing I said was intended as a putdown of your car. Every unibody convertible I have ever driven in, if you look at the gap between the door and quarter as you drive down the road, the gap opens and closes over bumps (sometimes quite a bit) which makes you think that every convertible should have a full frame instead of just adding supports to the unibody. Who knows what advantage or disadvantage the TQ frame has? There's certainly no reason to change the frame if your car has been fine for all these years since that accident.

Its Funny that you mention that the “bodywork we've uncovered has been pretty good for the most part and of that era in methods. It wasn't unusual to piece cars together back them”. The piece together part describes the quarter panel replacement on my car with a ’69 300 2dr sedan brazed over part of the original quarter so it ended up crooked, they obviously didn’t know the wheel well was different between a convertible and sedan or feel there was any reason to attach the bracing in the trunk so they just left it all dangling.

I only know that the Newport and 300 convertibles came with the factory door edge guards, I am not sure if it was standard on the Dodge and Plymouth convertible models.

I never took anything you said as a putdown of my car. Not at all.... and no, I won't be changing my stub frame anytime soon.

I think we all want to know what fits what and we've learned something here.

I would really like to see what the core support differences are. I'm still not clear on that. While I think I know the answer, I would like to see a 69 floor pan to see if it has provisions for the longer TQ frame. It probably doesn't, but it would still be interesting to see.

On a side note, the great thing about some of the original collision work in my car, including quarter panel replacement, was everything was welded. The good, old fashioned gas welds looked really good and there was no bubbling of the filler or paint on any of this work. Later work, obviously by someone else, left something to be desired.

 

[Fratzog]

As usual coming to this thread way late. Thanks for the great info Sevnt300.

 

[sevnt300]

Edge guards being standard on convertibles is gonna make me have to look that up. I'm not calling you on it, but I'm not signing up to it either. Until I check.

I stand corrected, only the 300 convertibles came standard with the door edge guards, on the Newport's it was optional. The door edge guards were not available if the car was equipped with the vinyl body protective molding.


1970 300



1970 Newport

 

[sevnt300]

I would like to see a 69 floor pan to see if it has provisions for the longer TQ frame. It probably doesn't, but it would still be interesting to see.

1969 Fury convertible



1969 Polara coupe

It doesn't appear that the '69's had any provision in the floor pans.

 

[commando1]

Will a stub frame from a 74+ fit a 71-73 car?

Posted via Topify on Android

 

[Big_John]

It doesn't appear that the '69's had any provision in the floor pans.

Hard to tell from those pictures, but yes, that appears there is no locating dimple in the pan.

I think the real question is if there is the reinforcement under the floor pan for the frame horn to bolt to. It would not surprise me if that was there.

If the reinforcement is there on the 69 car, then an "upgrade" to the TQ stub would just be a matter of locating and drilling a couple holes.

 

[polara71]

I would really like to see what the core support differences are. I'm still not clear on that.

John, I did post a few photos of the differences though they may not be exactly clear on what is what. As I said, both the same height

 

[sevnt300]

John, I did post a few photos of the differences though they may not be exactly clear on what is what. As I said, both the same height

I would really like to see what the core support differences are. I'm still not clear on that. While I think I know the answer

View attachment 37736

Rigid frame radiator core support measures about 15 inches from where it mounts to the frame

View attachment 37738

TQ frame radiator core support measures about 14 inches from where it mounts to the frame

View attachment 37737View attachment 37739

Both measure the same in the middle of the radiator about 21 1/2 inches

View attachment 37740View attachment 37736

TQ frame Rigid frame

If you notice there is an extra gusset running from the top to the bottom and an offset bracket for the rubber isolator on the TQ frame.
The rigid support has no such provisions. The wheel houses bolt up to their respective core support or "yoke" so the rigid mount wheel
house would be too long for the TQ yoke and the TQ wheel house would be too short for the rigid mount yoke. Small difference but
enough to make your life hell when trying to assemble the car.

 

[polara71]

The Torsion Quiet radiator core support is about 2” shorter (top to bottom) than the rigid mount support to accommodate the rubber isolators.

View attachment 37736

Rigid frame radiator core support measures about 15 inches from where it mounts to the frame

View attachment 37738

TQ frame radiator core support measures about 14 inches from where it mounts to the frame

View attachment 37737View attachment 37739

Both measure the same in the middle of the radiator about 21 1/2 inches

View attachment 37740View attachment 37736

TQ frame Rigid frame

If you notice there is an extra gusset running from the top to the bottom and an offset bracket for the rubber isolator on the TQ frame.
The rigid support has no such provisions. The wheel houses bolt up to their respective core support or "yoke" so the rigid mount wheel
house would be too long for the TQ yoke and the TQ wheel house would be too short for the rigid mount yoke. Small difference but
enough to make your life hell when trying to assemble the car.

Just trying to be clear because that isnt what you wrote on page one. With all the confusion on front frames and all the misleading information it needs to be clear

 

[sevnt300]

Will a stub frame from a 74+ fit a 71-73 car?

Posted via Topify on Android

If I had manuals for the later cars I could help you and cross reference them but I don't have specs for those years.

 

[Big_John]

The attachments don't show.