Best way to tell if leaf springs are still good

[biomedtechguy]

For you guys with springs that are flat. Aren't you getting wheel hop when doing a burnout?

That's a great example. I never noticed any wheel hop (see/hear video) either on the BF GOODRICH T/A radials, which were hopeless in the attempt to grab tarmac in the presence of gobs of torque, nor the Toyo Proxes TQ drag radials, which will also spin but grab much better.
What I did notice, without any video evidence, was how bad the axle wrapped up under the force of a launch at the drag strip, but that only became evident when it bent the thick, strong "[ shaped" steel of the pinion snubber bracket.
EDIT: Here's a couple of videos from a few years ago with the old springs and the "slippery" BFG T/A radials. I can't hear, see, or detect any wheel hop:

AND

I bought a couple of "Go Pro" type cameras and a 180°/360° camera, but I haven't used them at the track yet, mainly because I haven’t been in WAY too long. My intention is to have a lot more videos, to share and diagnose my launch.
I have trouble with getting videos from the track, because when I ask my best friends to shoot a video, well, I get results like THIS:

 

[odin]

Look at how far back the shackle is on the next to the last photo. Those are flatter than the pics show.

yes exactly. that shackle angle is what made me most concerned and why I chose to reach out in this forum. It just doesn't seem like it would have much travel as is

 

[odin]

I'm gonna disagree with the masses. If those springs had more arch (with weight on wheels) , there would be many comments about the 'stink bug' stance it would have. Drive it, and see how it rides/ handles/ feels before throwing money at it.

I read in some places that the springs will be pretty close to appearing flat when under a load. I had never heard that before so I started reading as much as I could. I find both camps exist: flat springs are ok v. flat springs are shot.

 

[odin]

I gotta wonder if those springs are correct for that car. New axle perches, new u-bolts, and the rear shackles are pitched back that far ? Something ain't right there.

Dave Wise from MMC Detroit mentioned the same thing. He said the Plymouth springs in 1968 were about an inch longer than the Dodge springs and could cause this effect.

 

[hunt2elk]

Dave Wise from MMC Detroit mentioned the same thing. He said the Plymouth springs in 1968 were about an inch longer than the Dodge springs and could cause this effect.

The springs are the exact same Dodge vs Plymouth. The difference is in the rear spring frame mount. Dodge is 1" farther back than a Plymouth.

 

[dadsbee]

The springs are the exact same Dodge vs Plymouth. The difference is in the rear spring frame mount. Dodge is 1" farther back than a Plymouth.

Yep... and the Dodge front spring mount is an inch longer to the eye hole than Plymouth.

 

[biomedtechguy]

Dodge cars, E bodies and maybe others? had a longer wheelbase than the "more economical" Plymouth cars. Maybe that is a factor affecting the rear spring hangers?

 

[dadsbee]

Dodge cars, E bodies and maybe others? had a longer wheelbase than the "more economical" Plymouth cars. Maybe that is a factor affecting the rear spring hangers?

68 69 70 Dodge B body has a one inch longer wheel base than Plymouth. Only because the front hanger is one inch longer on the Dodge and rear shackle mount an inch further back. Springs are identical...

 

[Canadian1968]

68 69 70 Dodge B body has a one inch longer wheel base than Plymouth. Only because the front hanger is one inch longer on the Dodge and rear shackle mount an inch further back. Springs are identical...

So if I under stand this correctly ... longer wheel base was compensated by front hanger being longer still use the same spring? Or was the over all length between the front and rear mounting point different ?

 

[hunt2elk]

So if I under stand this correctly ... longer wheel base was compensated by front hanger being longer still use the same spring? Or was the over all length between the front and rear mounting point different ?

The springs are exactly the same. The front and rear spring mounting points are 1" farther to the rear on a Dodge, hence a 1" longer wheelbase compared to Plymouth.

 

[Charlie71rt]

Theoretically if the spring is flat and travels any farther, the eye to eye gets shorter the shackle will start to move forward and raise the back of the car although not as much as the reverse arch of the spring lower it.

 

[Canadian1968]

Theoretically if the spring is flat and travels any farther, the eye to eye gets shorter the shackle will start to move forward and raise the back of the car although not as much as the reverse arch of the spring lower it.

Say what ?

Maybe I miss understanding what you wrote , but as a spring sags or " flattens" . The ends of the springs do not get closer together .

And a worn spring does not raise the car

 

[khryslerkid]

I gotta wonder if those springs are correct for that car. New axle perches, new u-bolts, and the rear shackles are pitched back that far ? Something ain't right there.

Looking at all the other hardware and the dry cracked bushings, pitted springs, more than likely they're original.

 

[eldubb440]

shouldn't that car have an extra leaf on the pass side?

 

[WileERobby]

Looking at all the other hardware and the dry cracked bushings, pitted springs, more than likely they're original.

They're original from somewhere, not sure if those are RT springs from that car.

 

[myfeather626]

They sure look like they have see better days to me. I'm surprised the car isn't setting lower than it is. Give Laura at ESPO a call for new springs. They sell both the staggered XHD springs rated at 130 lbs. as well as matched 6 leaf HD's rated at 140 lbs. I have a set of each and no complaints.

I had mine re Arched at a local Spring Shop they put new spacers and the car really rides and hooks up nicely! The problem I see from your picture are the Bottom Shackle Plates and the U Bolts are incorrect!!! Pull one off and be sure your U Bolts have the x Hatching on the top inside of the U bolts? The Bottom Plates look like they are leaning back and not original? Just from what I can make out from the photos!

 

[myfeather626]

I recently picked up a 68 Charger RT and know very little about the car. I noticed the leaf springs are almost flat and straight when I was under the car the other day. The springs appear to be exactly the same on both sides with five complete leafs (no halfs). The rear shackles are leaning very far back leaving only about a half inch from the rear eye to the frame rail. I plan on replacing all the bushings, but wanted everyone's opinion regarding the flatness of the springs and the angle of the shackles. I read other posts and it would seem many people say the best way to tell if the leaf springs need replaced is by how the car drives and not necessarily from looking at the arch of the spring. Some folks on here also say there should be a positive arch in the spring while others say they should be flat when on the car.

Shouldn't RT cars have 5+half leafs on the left side and 5+two half leafs on the right side?

Do these springs appear too flat or not bad enough to worry about for now? (just appearance for now: I will drive it once I get the transmission replaced)


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Those are Aftermarket Brackets all wrong!

 

[hunt2elk]

I had mine re Arched at a local Spring Shop they put new spacers and the car really rides and hooks up nicely! The problem I see from your picture are the Bottom Shackle Plates and the U Bolts are incorrect!!! Pull one off and be sure your U Bolts have the x Hatching on the top inside of the U bolts? The Bottom Plates look like they are leaning back and not original? Just from what I can make out from the photos!

Not my car, so couldn't tell you......