Leaf spring selection for minimal consistent load

So I'm just around 20K on the truck, have +2 CB shackles in the back with factory leafs and a 3 inch coil over spacer in the front. My leaf springs are ridiculously flat, so much so that I have a little bit of reverse rake with my set up and when I put anything it in, it droops real bad. I have been looking into alternate leaf spring options (icon, deavers, dobisons, add a leaf, etc). I tow every once in a while some heavy equipment, and will do a few loads of mulch a year with some paver stones, rocks, things like that. I probably have about 40 or 50lbs of weight in the back consistently with my tools, but nothing more. Icon's are on sale right now at $303 per spring, but it seems like there's not a whole lot of feedback on people using option 1 on the icons either unloaded or at a low load, and option 2 may be too much rake for a consistent load of only 50lbs (I'm okay with a little bit of rake) and it could make my ride pretty rough if not loaded. I was actually leaning more towards just adding a leaf for a little bit of extra support and lift while maintaining a smooth ride, but wanted to see others opinions for those that have gone either the add a leaf or new leaf spring route unloaded or with minimal load. Thanks.

 

If your going the leaf spring route I would bite the bullet and do it right with deavers. If you tow or do heavy hauls, adding ras might be good too

 

I was afraid someone would say that ha. They certainly are pricey. But probably with my use they’ll last a real long time. I wonder if the CB shackles are compatible with them.

 

Deavers says you have to use the total chaos shackles because they are longer than stocks but I am sure there are people on here that can let you know for sure. Deavers is close to me so I plan to go there and have them look at my setup in person and do the install themselves. I would definitely call them and talk all the details.

I've never heard anyone say their deavers flattened out but I have heard people say that about icons and OME.

 

Yeah it sounds like they are the way to go for sure. I’ll give them a call. Thanks.

 

Another plug for Deaver. I’ve got about 30,000 miles on my fat pig CrewMax since installing my U748 packs. I tow as heavy as anyone should with this truck, and have over 3,000 miles towing my travel trailer since putting these springs in.
They’re still perfect. They ride amazing. They perform well and carry the loads I need without issue.

The only hard part is the cost. You need to process that part and convince yourself that it’s the right choice. Look at it like this…. They’re cheaper than new wheels, which many of us buy without much thought. They’ll likely provide more benefit than new wheels…


Additionally, I’ve only heard great things about Alcan springs. I do not have first hand experience with them though.

 

I figure with the removal and install and refurb, I could buy a used set of stocks from the forum and plus, stock leafs suck anyway lol

 

Another option you might want to look at is Roadactive Suspension.

 

I was under the impression that Deavers are not a good option for vehicles used for towing - unless they are consistently used for towing. If you go from empty street machine to loaded tow rig then Deavers might not be your first choice? From what I’ve seen, Deavers, Alcans, and the like are typically built for a specific setup: overland ER with constant load, high speed desert chaser that never tows, etc. Reason being, they don’t typically build in a lot of overload like the factory spring. They build a progressive curve for a constant load. I’m not saying they can’t build such a spring, but building overloads in to a spring packs limits the travel as the spring rate ramps up quickly. And that is exactly what the factory leaves do and why it gives a “pickup truck” ride - because it’s a pickup meant to do truck things.

This supposition is further evidenced by the suggestions above of adding a secondary load device such as air bags or RAS to supplement the Deavers. I have to scratch my head at having a custom set of springs built only to muck around with it after the fact by adding a secondary load device. Shouldn’t a custom set of springs get you where you want to be in the first place? But by adding overload capacity, doesn’t that just put you back to where you are at with a stock setup?

I’m not trying to bag on anybody or poopoo their suggestions, just questioning the logic.

If it were me, I’d thing about removing the factory overload from the pack, then adding air bags or RAS. Possible a 3 leaf add a leaf from Icon or ……(who’s the other place besides Wheelers??); they retain only the main leaf and overload, but suggest removing the overload for an improved ride.

But first, I’d look at the shock absorbers. Ditch the factory shocks and look for a plusher option like Fox floats or custom valves adjustable. factory shock absorbers are sufficient, not ideal. The shock absorber, IMO, will make a much bigger difference in the ride and handling than the spring. Used in conjunction and you have a total system change.

Personally, I didn’t like the cushy feeling of the Fox 2.0’s or Eibach pro truck rears because they were too comfy. I know that sounds strange, but it’s true. And that might be perfect for your setup as my truck is never empty. I run around loaded and trailering, and I take the twisties at speed, so I’m ok with the stiffer ride trade off. But for all of $300 a pair, they are an inexpensive way to make a significant change to the ride.

Lastly, fiddle with your tire pressure. That’s the first part of your suspension. Air up when towing, air down while unloaded. Portable inflators are pretty cheap. If you are a big red tool junkie like me, Milwaukee makes a pretty slick m18 inflator that can be worth its weight in gold. It’s fast, too. I had to let my tires down to 20 psi to get my truck and trailer out of a fun little inclined spot I’d parked on in the middle of nowhere as a snowstorm rolled in dropping several inches an hour (not blizzard by any means, but when you started with 6” of wet snow and falling temperatures on top of at least a foot of hard pack snow/ice it made for a fun evening by myself in the middle of nowhere without cell service). Once I made it back to better conditions, took me all of 10 minutes to push the tires back up to 43 psi.

 

Custom deaver pack here on the old man’s rig. Awesome pack. They’ve felt better than the custom Alcan pack previously.

 

I’d think any issues with Deaver being able to periodically pack a load would have come to light by now in my situation. 10% of my use since installing has been heavy.
That said, I use a WDH that is set up well. Maybe it’s different if folks were putting all the weight on the rear suspension.

 

If your factory leafs are flat, you need new springs. I’ve been told the 2.5” Tundra leafs just don’t have the longevity that all the other 3” truck springs have, so regardless of your replacement choice they will likely fail at some point if you tow/haul heavy. I went with Dobinsons, and the Roadmaster Active Suspension HD to go with them. Dobinsons are rated about +150lbs cargo capacity than stock, and the RAS makes the suspension behave like I wish it had come from the factory while hopefully keeping the springs from failing as quickly. It got me about a 2.5” lift from stock, bit of a guess as my factory springs were already sprung when I replaced them.

There are tons of reviews on the RAS on this site, a couple of them are mine. It tows great, rides great unloaded, and may or may not have caught some air earlier today and came down nice and smooth with the family on board.

 

It's not that the springs are defective or have issues, it's just that the application appears incorrect. Using a leaf spring calculator, lets look at a few scenarios. Whether or not the numbers are entirely accurate is less important than the pattern that we see. Lets start with the factory leaf spring, which I went out and roughly measured. The first screenshot is the spring rate without the overload since it is not engaged with the primary load . The second is with the overload fully engaged (which I suspect is probably close to where the bumps start to contact axle and frame). The third screenshot would be thinner leaves with a linear digression of 4" shorter per leaf (2" shorter on either side of the axle). The fourth screenshot is for leaves every 4" from the factory leaves longest leaf to the overload leaf.

Note: the assumption of thinner leaves of .25" thick is made. The original leaf pack would be ~1.8375" thick from just the leaves, or 1.0625" thick without the overload. The first aftermarket leaf pack would be 1.75" thick (slightly thinner than the factory pack with the overload). The second aftermarket pack would be 2.5" thick.

Factory Leaves, no overload



Factory Leaves With Overload




New Leaf Pack with .25" thick leaves, ~4" digressive leaf length



New 10-Leaf pack with ~4" digression from factory main leaf length to overload length



I'm not an expert in the field but I do try to learn what I can about whatever I can. I have done a few suspension upgrades to my rig over the years to accommodate my changing needs including shackles, air bags, icon 3 leaf pack, and multiple sets of shock absorbers. Some things worked as planned, some not so much. Almost all of them were recommended by this site or other tundra sites. Many of the changes included emails and/or phone calls with manufactures to try and find the best solution to my needs.

But this is the point I'm trying to illustrate: calibrating suspension for a specific load or small range load is much easier than calculating it for a large range of loads - at least when it comes to suspension compliance and ride quality. Most 3/4 ton and 1 ton trucks come with one or two sets of overload springs so as not to knock the fillings out of your head while driving around unloaded. As with everything, there are tradeoffs. Are you accomplishing what you set out for, or compromising too much for the expensive, shiny stickers that come in the new swag?

*EDITED last chart as I had some erroneous data entered

 

I like what you’ve put together and certainly can’t argue with science.

From my personal experience, hauling any decent load with factory springs was unpleasant. Even with 4 men and about 500# of gear in the bed. We did that for a fast run down to San Diego for fishing, and the fellas in the back seat were crying the whole way down I-5 because we were slamming bump stops. I put bags on, which helped a lot. I even left the bags in place after installing the Deaver springs, but took them out after a few months because I never used them. What they did at that point was act as bump stops and prevent my nice shocks from doing their job completely. I removed the bags and put hydro bumps in. Suspension is much happier now, as that weird rate build that is inherent with bags is gone.
With my WDH set, the rear suspension squats less than 2” from trailer tongue weight. The front goes down a little over 1/4”.

I’m sure you’re correct that it’s tough to build a spring that does it all. That 100% makes sense. I’m not convinced that the Deaver U748 is the perfect spring for everything, but it sure does everything I ask of it a heluva lot nicer than the OEM set.

I do bang into my hydro bumps on occasion, but haven’t compressed them beyond 50-60% yet. Every once in a while, I’ll slide the rubber bands back up to monitor activity.