Generic question regarding leaf springs

[Kern Dog]

If a vehicle sits at an acceptable ride height but bottoms out easily, is that a matter of weak shocks or weak springs?
My 2007 Ram 1500 rides nice and sits at the same height it has for the nearly 13 years that I have owned it but the rear axle hits the bumpstops too easily.
I ask because my logic tells me that if a spring supports a vehicle, it is not weak. Am I wrong?
I suspect that I actually need new shocks.

 

[khryslerkid]

I think your suspect is correct

 

[66 Sat]

Hmmm, has it always hit the bump stops too easily or has this happened over time? More likely worn out shocks if it's only happening now. Could the leaf springs be strong in their unladed curved shape, but then weaken as they flatten when you hit a bump? Maybe add some weight to the tray when the truck is static and see how much it sags?

 

[Jerry Hall]

I think you're thinking is correct. You need new shocks.
I'm fixing to buy shocks at all 4 corners on my 2004 Dodge 2500 CTD. 300K miles. I don't actually have the same problem as you so here goes. The truck rides OK, unloaded and the springs support the load when towing or heavy loads in the bed. For about the last year especially when towing it will beat you to death in ride quality. My bumpers do not indicate that they are bottoming out.

 

[steve340]

Shocks only damp oscillation I would say springs. Most stock springs have a fairly low spring rate - the amount it takes to compress the spring.
However the springs and shocks probably both need replacement. 13 years is a pretty long service time. I am assuming it has done a few miles.

 

[khryslerkid]

The old test is to bounce the vehicle. If it bounces twice you need new shocks. It should stop the second you stop bouncing it.

If they show signs of wetness, leaking fluid, they're definitely bad. That's how I found one on the rear that acually wore a tire.

 

[Kern Dog]

I called a local spring shop today. The man said that it is possible for the springs to be capable of maintaining the ride height but be worn enough to compress easily BUT he has never seen it happen in 7 years in the trade. He did suggest new shocks and to check back with him if the problem persists.
It is great when a business has the integrity to steer you right instead of just reaching for your wallet.

 

[kiwigtx]

My limited understanding of springs and shocks is basically this...

The Springs determine the ride height and carry the load.

Shocks control the rate at which the springs are allowed to travel - flex or whatever you want to call it.

 

[Kern Dog]

I've finally had some success here so I thought I'd respond with an update.
Yesterday I bought a pair of stock rear bumpstops and cut them down a bit. I looked at the overload spring at the bottom of the leaf spring packs and it looked to have a downward curve to it. I figured that if I flipped it over, it might provide a little bit of lift. It did not....in fact, after getting home from my 214 mile round trip commute, the truck was 1/2" LOWER in back! What??
I did stop at a Pick-N-Pull yard and get two spring packs from a fairly clean 2005 Ram 1500 short bed. I got lucky too....Someone had alread taken the rear axle so the springs were an easy grab.
Back at home, I swapped in the springs along with new shocks on the back. I ordered a set of Bilsteins on Saturday and they were here this afternoon.
The ride height came up to over 1/2" above what it was before I did anything. There is a decent amount of suspension travel and these shocks are fantastic. I have Bilsteins in my '70 Charger and the Wife's 2015 Challenger.
The ride feels like a new truck. No wallowing, no bouncy response to bumps and the general loose feeling is gone. I still need to replace the front shocks but this was a great victory!

 

[Kern Dog]

The Bilstein shocks helped a great amount but the rear still bottoms out too easily. Today something occurred to me.
Originally, I was questioning if it was possible for a spring to be able to hold it's shape and support a vehicle but still bottom out easily.
This is what occurred to me:
A slant six torsion bar can support a B body with an all iron Hemi if it is cranked up enough. Wouldn't the same apply to a leaf spring if it is arched enough? The slant six torsion bars would likely result in a more bouncy ride with greater suspension movement compared to a 1.15 torsion bar.
I am thinking that what I need is to add spring rate without adding much to the ride height. The stock leaf spring pack has a thick overload spring that is installed with the arch pointing down so it really only comes into play once the suspension has travelled a great deal. I am thinking of reversing the overload spring to see if it will help.

 

[steve340]

You would be best to remove the springs from the vehicle and take them to a spring maker and have a leaf added to the spring pack.
As I mentioned in my earlier post you need to increase the spring rate.
You can get the spring set back to the same ride height it will just be stiffer to compress.

 

[Kern Dog]

However the springs and shocks probably both need replacement. 13 years is a pretty long service time. I am assuming it has done a few miles.

Miles.....
How about 338,000 ??

 

[Curiousyellow71]

I think your not noticing your ride height drop is because the back of a1500 pickup isn't very heavy. If you put a load on it now vs when it was new I bet it would sag. I have experienced springs that looked fine/stood fine and wouldn't carry weight and would bottom out easy. Maybe consider adding air bag load helper kit that bolt on outside the frame rails. They are easy to install.

 

[Cranky]

Yup, shocks damp oscillation but when the shocks get old, they don't control the oscillation very well. Run it without shocks and you'll find out just what a shock does!! It'll act like a basket ball or any kind of a aired up ball for that matter. Just bought a 96 Dakota and it had a stiff but bouncy ride in the rear. It acted closer to just having the tires as a suspension. It had overload coils/shocks on it so I cut the coils springs off and put the same shocks back on. The rear height came down a good 1 1/2" which is more close to stock. The ride is still a bit stiff but that bouncy crap is gone.

You can add a leaf if you want more carrying capacity rather than turn over the overload leaf. Usually if you add spring, you need to go with a bit more shock to help control the higher spring rate but your Bilsteins will probably be fine. You can go overboard though if you want a 1 ton ride Had a single wheel 1 ton years ago and that thing didn't need shocks so long as it was empty lol

 

[Dennis H]

You get a Medal for spending 338k miles behind the wheel of the truck. I can’t comprehend.
54k on the 06, 14k on the 09.

 

[Cranky]

Until the other day, I had 4 registered vehicles....a 95 Dakota with 101k miles but it looks and feels like 300k! Just bought a 96 Dakota with 130k but it feels and runs like it has 25k miles and a 97 diesel with 140k miles. Just sold a 98 Jeep with 238K miles but only put about 1000 miles on it. I only put 76k miles on the 95 and about 40k on the diesel. Just don't do much driving anymore. Had the 95 since 98 and the 97 since around 2001......

 

[69a100]

40+ years ago when I was learning to drive, I was told that shocks have a lifespan of about 20,000 miles. Don't know if that still holds true in today's world??

 

[Jerry Hall]

I have 2 2500 Dodge diesels. 2004 that likes less than 100 miles to be at 300K. An 2006 that is at 130K. The springs on both perform like they did when new. The front end of the 04 was just totally rebuilt along with 4 new OE shocks. The 06 has had nothing done. Both ride and perform as new. I cannot relate to the springs on a 07 1500. The picture posted of the trunk tells me that it hasn't been beat or abused. I understand shock wear, but springs I cannot explain.

 

[kiwigtx]

40+ years ago when I was learning to drive, I was told that shocks have a lifespan of about 20,000 miles. Don't know if that still holds true in today's world??

Less if they're Chinese made.

 

[Cranky]

40+ years ago when I was learning to drive, I was told that shocks have a lifespan of about 20,000 miles. Don't know if that still holds true in today's world??

Cars of the 60's.....had shocks on them that were more or less.....a 2 dollar shock. The 66 Belvedere I got in mid 69 still had the factory shocks and that was the first thing I replace. Made a huge difference in the way the car rode and handled. The car was still riding pretty much like it did when it was new because it was bought new by my dad.