Best way to tell if leaf springs are still good

[odin]

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)

 

[ckessel]

Side view of the car looks ok but the shots of the shackles, plus flat springs, say it's time for new ones. They don't last forever. Same goes on the t-bars. I gifted my old ones to a guy to forward on to people making knives. Great material for those. I put in the XHD units, purchased from Firm Feel several years ago. I have no feedback to offer on ride, ride height etc as the car is still under construction.

 

[Canadian1968]

Mine are looking about the same... interested in what other people say.

 

[toolmanmike]

Side view of the car looks ok but the shots of the shackles, plus flat springs, say it's time for new ones. They don't last forever. Same goes on the t-bars. I gifted my old ones to a guy to forward on to people making knives. Great material for those. I put in the XHD units, purchased from Firm Feel several years ago. I have no feedback to offer on ride, ride height etc as the car is still under construction.

I agree there. It sets ok but I can't see what size tire is on it. If the springs are flat or have a reverse arch you need some new ones. I have dealt with ESPO with excellent results.

 

[hunt2elk]

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.

 

[toolmanmike]

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

 

[roadrunnerh]

...sweet looking 1968 Charger!

 

[WileE]

Your springs are shot.

 

[Dako]

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.

 

[dadsbee]

Amazing what new zinc interleafs and plastic wear pads will do....

 

[ckessel]

Toss some people in the car and take it for a drive on some country roads. Somewhat rough would be good. When you get back and the car is unloaded, look to see if the rear spring eye has kissed the frame. If yes, spring for some springs. Ha. If no, something to watch for in the future.

 

[4speed68rt]

I think R/T has 7 on one side and 6 on the other. Are you sure that is an R/T? Somebody may have changed them out at some point and put the 5 and 5 setup from a non R/T. I'd say that if you are open to changing them, now is as good of a time as any. They are old and flat. It could only improve the car.

 

[WileE]

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.

 

[Photon440]

The springs should have some arch when there's nothing in the trunk, BUT it also mentions in the Mopar book on suspensions that the best handling is achieved when the springs are flat

 

[WileE]

The springs should have some arch when there's nothing in the trunk, BUT it also mentions in the Mopar book on suspensions that the best handling is achieved when the springs are flat

 

[ckessel]

There were some springs offered through the Kit Car program that had +1", 0+[flat] or -1" on the arch. They of course had a higher spring rate, would have to look in my books to see what they were. I had the 0 units on my 70 Challenger.

 

[Canadian1968]

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.

Not quite as bad as the OP but these are mine in my real 68 R/T with its original leafs.

Feel like my shackles are pretty far rearward as well

 

[WileE]

Not quite as bad as the OP but these are mine in my real 68 R/T with its original leafs.

Feel like my shackles are pretty far rearward as well

View attachment 1528468

View attachment 1528469

View attachment 1528470

Hard to see in pics by my ol' eyeballs, but the op's springs appear thin.

 

[biomedtechguy]

All of the comments are interesting, but the decision for me, the only indication I could recognize my springs needed replacing was after getting Mancini's top of the line pinion snubber. That heavy gauge mount bent on my first launch at the drag strip! I decided to make another pass, and that bent it badly enough to have to remove it right away.
It didn't take Columbo to figure out the springs were torque wrapping so badly as to bend the snubber mount.
This is similar to other posts in that it required actually imparting mechanical forces to decide.

 

[hunt2elk]

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