Leaf Spring Replacement - Standard or HD

[Aquaman]

I've read a number of the posts about leaf springs here and am close to buying new ones. I'm looking at ESPO and Eaton. ESPO pricing is better.

Question: Both offer Standard or HD. I am staying at stock height. Will ride quality be the same with the HD?

I hope to take some road trips when all is said and done and want to be able to "load her up" without sagging.

Thoughts and insights from those who have used the standard and HD rating on these will be appreciated.

 

[Big_John]

Refresh my memory about what car you have.

Yes, I think ESPO is a little cheaper and overall is going to be cheaper shipping because PA is closer to you.

IMHO, the leaf springs on your car are going to be enough to handle a trunk full of luggage. Start stuffing a lot of people in and maybe heavier camping supplies. it may sag.

The downside of HD springs is the car is going to ride harder the rest of the time.

I have stock springs in my cars, and I load them up with luggage and they don't sag.

 

[Aquaman]

Refresh my memory about what car you have.

Yes, I think ESPO is a little cheaper and overall is going to be cheaper shipping because PA is closer to you.

IMHO, the leaf springs on your car are going to be enough to handle a trunk full of luggage. Start stuffing a lot of people in and maybe heavier camping supplies. it may sag.

The downside of HD springs is the car is going to ride harder the rest of the time.

I have stock springs in my cars, and I load them up with luggage and they don't sag.

1968 Newport 4D Hard Top - 383

 

[Luke Pokrajac]

I just installed the HD leaf springs from ESPO on my 68 Sport Fury. THEY RIDE GREAT!! If anything they are a weee bit soft. I had an issue with the car where it would always wander on the road...even after much work to the front end and addition of Borgeson steering box. It turns out that rear spring bushings were so bad that the rear axle was steering the car enough to make it wander. I'm very happy with the new ESPO springs.

 

[CBODY67]

As I recall, the Eaton website has the spring specs (as to ride rate and such).

As to "sag", back in college, I volunteered to hawl beer kegs to a party from the beer distributor, in the 1966 Newport Town Sedan. Sag? Certainly with three kegs in the trunk. BUT not on the bump stops! I drove slow and easy, so they would not roll around (could have put a 4th one in there). Just that one time, about 15 miles on smooth roads.

With the HD springs, you might need to tweak the torsion bars up a bit to remain level.

I know that some might gnash their teeth, but IF the upper shock mount crossmember is not rusty/rusted, put some good air shocks on the back so you can level the car no matter the load in the back. Then, when done, let the air out, and you have a large-piston HD shock in the back.

As I recall, "Max Rated Load" is with 6 (150lbs, each) passengers and 500lbs of luggage. So, DO adjust tire pressures accordingly. The car WILL ride a bit lower with that weight, so ground clearance will be less, too.

Just some thoughts,
CBODY67

 

[Big_John]

1968 Newport 4D Hard Top - 383

Just for laughs, I did some poking around and found the Newport had 5 1/2 leaves and everything else had 6 1/2 leaves. The torsion bars have 2 options, one for cars without AC and one for cars without AC.

The HD rear leaf option for the Newport is 6 1/2 leaves which is the same as everything else.

Thinking about it, the HD might be a good option, although I'll stand behind what I said about a stiffer ride. It may not be enough to worry about or even notice. One thing that I always see is people comparing old worn junk to new. Leaf springs get a little rusty and they don't slide as well, so switching to a stiffer spring isn't going to make much change in ride. Bad rubber bushings will make the car ride harder too and again switching to new makes everything ride nice again.

So, it's up to you. It's not a bad idea and thinking about it, I'd consider it myself with a Newport. My reference to my own cars are 300s and one is a convertible, so their stock springs would be the HD springs for the Newport, so even my experience is "apples and oranges".

I know that some might gnash their teeth, but IF the upper shock mount crossmember is not rusty/rusted, put some good air shocks on the back so you can level the car no matter the load in the back. Then, when done, let the air out, and you have a large-piston HD shock in the back.

Gnash.. gnash... I'm not a fan of air shocks in general, but he does make a good point. As long as you aren't using them as a band aid to correct bad springs, it's not a bad idea. Too much load on the bit of frame that is made for attaching the shocks and not supporting the car is a bad idea, but a little leveling action on a car with good suspension isn't bad.

I'm still going to gnash my teeth just under general principal because I have had to repair a shock crossmember on a car years ago that was destroyed by air shocks that were used incorrectly.

 

[cbarge]

If I remember correctly, ESPO offers a 1" higher arch in the standard spring.
A luttle lift yet still nice ride- not harsh.
I did that on my 73 Satellite wagon.

 

[413]

These cars are so heavy and long wheelbase the HD would be money well spent. If it rides hard just keep tank full

 

[CBODY67]

NOW . . . I am NOT going to dismiss the fact that TX used far less salt on the roads in winter than what happened where @Big_John is in the winter, but my experiences with air shocks is much different and long-term. When the L60s were common on "hot rods", air shocks were used to raise the body above normal factory ride height so the tires would clear. Tires that were not needed as much as suspected. PLUS the raising of the rear body lessened the amount of weight back there, further making good "hook ups" elusive for some. As the added tire smoke made the car look more powerful than it might have been if it had had normal size tires with a stickier compound in them. But that was the style in the later 1960s!

As to the degrading of the shock mounting crossmember due to environmental issues (even salty coastal air in warmer climates!) could also happen with normal cars and really stiff shocks. Stiffer than normal Monroe Super 500s, back then.

The shock absorber is always putting "forces" into the upper mounting point. Usually more gentle than sharp. But I suspect a sharp force could compromise a further-compromised shock mounting location, too. One quick "bottom out" could do it. From the sudden spike in forces felt by the upper shock mount and what it attached to. Whether there might be an air shock under that mount or a normal XHD shock under it.

I saw several guys with their rear air shocks pumped up to the max, so they could put those L60s on the back. No doubt, the upper shock mounts took a beating, even down here. Which also meant those cars were riding worse than a buckboard. But the owners thought they "looked cool", and that was all that mattered. Usually, their later cars had normal tires at more normal ride height to them.

It was also in these times that we learned that longer rear shackles did not raise the rear end of a Chrysler product very much at all. Which was the other method of raising the rear of the car for tire clearance to look powerful. Worked well on Camaros, though.

Different places, different experiences.

CBODY67

 

[Aquaman]

Thanks all! This is a low / no rust car I bought out of Tennessee ~20 years ago. Very good overall condition body, "frame" and interior that I am updating and renewing tip to tail. My hope is to have many road trips when done.

I'm leaning toward the HD. Currently redoing the front end. Engine and transmission to come out some time between doing the front and back.

 

[HWYCRZR]

I ordered a set of “Stock” springs for my’68 Polara. Mine have 5-1/2 leaves the new ones have 6. They offered to do 5-1/2 for an extra $15 . Any way it seems that for Polara the heavy duty were on 440 cars and towing package. There seems to be a mid range one based on the part numbers for police and taxi. But couldn’t find the exact information.
Any way for me ESPO was about 1/2 of Eaton. I ordered them in mid January so hopefully get them in April.

This was the quote I got in late November. Likely up from that after the first of the year.

The 6-leaf springs are $410/pair. The 7-leaf are $420/pair. Our springs are all full leaves but we could do the last as a half leaf if you want, it'd be $15 extra for the pair. They are matched arch pairs and come with the front bushings pressed in. Rear shackles with bushings are $98/pair or bushings separate $20/set of 8; ubolts $24/set of 4 and front eye bolts $9/pair.

 

[Dsertdog]

I'm not sure what one would want on a four door

I ordered ESPOs with the 1-inch lift. As installed the rear was about two inches over where the car sat with the worn-out springs. It took about 2 or 3 weeks for it to settle.
I run 30-35 lbs. in my air shocks (the minimum is 25) and I'm happy with the ride, but even happier with both the look and handling. My wife and I are both big people and the car sets at a nice rake with both of us in it.

 

[68_fury_ragtop]

I went with the HD and stock height on my Fury. No issues with a rough ride. The extra capacity comes in useful going on road trips with luggage, tools and spare parts. I had a problem with ESPO's springs years ago on my Belvedere. After putting them on, it looked like the car had a cord of wood in the trunk. I think the 50 year old springs sat higher. I swore to never get anything from them again after the run around they gave me.

 

[wyrmrider]

Ii added a leaf starti ng with some Wagon springs stiffened up a little but handeled much better
I put the plastic interliners in spring width with an H shape sprayed some moly spray on them
I used a Cordoba rear sway
and get front torsion bars from a late cop car or wagon
wider wheels, I used cop wheelsi
springs are not hard to rebuild
clean them up with a belt sander and spray with zinkchromate no stiction

 

[volksworld]

i'd try to check with manufacturer to see exactly what the difference between std and hd...if they both have the same arch and leaf thickness, and the only difference is one extra leaf I'd go with the HD and if you don't like the ride you could just remove a leaf...(one of the long ones,not the short one on the bottom, it prevents wrap up and wheel hop...

 

[CaliFury]

I put on the ESPO springs on my 66 Fury about 6 months ago, with the 1" lift. It's an almost imperceptible rake and rides soooo nice! Do yourself a favor and throw in some new shocks while you're at it. Your car will ride like butter AND be able to go around a corner slightly higher than recommended speed for a change. Good Luck!