Leaf Pack : Dobinson vs Boise Spring vs Alcan

I'm thinking of removing my airbags and adding extra spring to my truck. Last year, I replaced the leaf pack with a set of factory takeoffs with about 2k miles on the, and modified the leaf pack with an Icon 3 leaf add a leaf. Unfortunately, it's not enough spring without the air bags, so I'm looking at alternatives. The Icon's ride better, but they just barely engage the overload if air down my bags. I scaled my truck with some surprising results - the rear axle is only at 3640 lbs. I have a camper shell, bed slide, and bed full gear, but I tow often, so I need extra constant load, as well as the ability to overload gracefully.

Local off road shop recommended Dobinson L59-1212-R which is the middle load pack. 400+ LBS constant load (which I have) for 2" of lift. But I really only want 1" of lift. Still want a rake in the suspension, but not total stink bug. The leaf pack is under $1000, but I don't like that they nickel and dime you another $500 for bushings, u bolts, and greasable shackles. The leaf pack looks to have a two stage overload, which would give me more confidence in removing the air bags. 5 leaves + 2 Overloads. With shipping, looking at $1500 before install.

https://exitoffroad.com/product/dobinsons-rear-leaf-springs-toyota-tundra-2007-2020/

Boise Spring Works offers three different options to replace the overload section of the leaf pack: 500, 1000, and 1500 lb increments, I believe. It replaces the thick overload spring at the bottom of the pack. Costs about $550+ shipping, so less than half of the dobinson pack. I'm told the leaf pack upgrade is awesome for slide in campers, but I don't know how well it does going from 600 lbs in the bed to 1000 lbs in the bed plus 500+ lbs tongue weight. Turns a stock leaf pack in to a 7 leaf pack without a standard overload.

https://d3ciwvs59ifrt8.cloudfront.n...5604/846b6798-5dcd-463b-bcb5-5b57879e4f32.pdf

Alcan custom leaf pack is another option. I hear a mixed bag but mostly positive reviews. It's custom, so lead time is out there a month or two. Or three. Pricewise, its on par with the Dobinson pack - maybe even a little cheaper. I can spec it as needed and hope I give them the right info for what I think I need. I don't know if they will spec anything more than a 7 leaf pack (not that I necessarily want a higher leaf count, but such a pack should be more progressive and give a better ride).

https://www.alcanspring.com

I spoke with my local spring shop and they just said they would add a leaf to my existing pack for $500 or so. Don't think I'll go that route, but I've used add a leaves successfully in the past.

Last option is a franken-pack. I have essentially two and a half leaf packs in my shop that I could could cut and stitch together to make my own leaf pack. Sounds like some work and a bit of a gamble, but I'm only out some time.

Any experience with the above-mentioned options. Talking out loud, I'm leaning toward Alcan's.

 

I have the Dobinson leaf you mentioned above, it is a great addition if you have any additional weight in the back, I have around 500lbs of constant load and think it is just right, and definitely take another 200-300lbs without additional sag. I got mine all in for less than 1k last year when it was on sale.

 

What are you trying to avoid or cure by getting rid of the bags?

I'm in a very similar situation to you. I have a DC with a fiberglass topper and decked drawers. When i had stock suspension i had a good bit of sag. I had airbags on my last truck, but i'm not a fan of the ride the airbags provide.

What i have done thus far is add the RAS HD system and cranked it up so i can fit both washer snugly. I also like the rake when "unloaded" as i tow as well and load the back of the truck and topper roof with dogs, fridge, junk, kayak, roof box, etc. I've been happy with the RAS so far, i got my height back plus a smidge more. the ride is very good, no noises or anything. I haven't towed anything very heavy (as in a TT) yet, but towing my utility trailer loaded up it does fine.

I was debating if it come to it to add an "add a leaf" to my current pack and see what that does with the RAS, but haven't found a need yet.

The Boise spring idea does sound intriguing to me. I would be tempted to try that route.

I had OME HD springs on my last truck (which i added the air bags to for heavy towing). I really liked the springs, would totally go OME again, but i don't need the lift. Only other complaint i hear about aftermarket springs (and I experienced it with my OME) is the squeaking. Not sure if the add a leaf approach has that issue.

 

You'll have to get some made if you want just 1" lift with a full pack and the benefits they provide.

It's not nickel and diming. When you buy a full suspension kit, all components are broken down and adding leaf springs requires new bushings since the OE ones are pressed in and almost impossible to remove without destroying them. And the spring pack is thicker, taller, so new ubolts are needed to make them fit.

 

That’s right around what I would expect to pay for that setup. Did you get around 2” of lift with it as loaded? I never weighed my truck stock and empty but I recall the dump scale saying around 5600 lbs with me in it. Seem to recall the rear being 2400-2600ish empty according to some techs at the dealership. Since I'm currently at 3640, I'm around 1000 lbs in the bed.

 

Airbags are great for a lot a reasons. They've done their job for several years, but they do limit suspension up travel in the way that the bag pressure increases as the spring compresses - meaning the spring rate ramps up quickly. Leaf springs do the same thing, but typically at a slower rate (spring compresses more) until hitting the overload spring. The bags have a very small sweet spot where they are super smooth; in my experience, this point is where you start unloading the leaf spring and supporting the additional load AND part of the vehicle weight with the bags. This essentially lifts the back end a little bit. It may also just be that it's unloading the overload so the bag spring rate plus the leaf spring rate without overload spring is much lower. IIRC, the spring rate on our overload springs is somewhere in the 4000# / inch rate, while the rest of the leaf pack with all the leaves engaged is closer to 1000# / inch.

My old 5160 Bilsteins had a little rubber o ring on the shock shaft; it NEVER got closer than 3 or 4 inches or so away from bottoming the shaft. Yes, that means I never bottomed out the suspension which his a good thing, but it also means I was never using that additional 4" of up travel (shock and suspension compressing), even while low speed maneuvering through ditches and such. This gives credence to my statement above about the bags building spring rate very quickly and limiting up travel.

Ideally, I'd like a smoother ride with my standard load out while achieving ~ 1" of lift in the back to maintain rake (2+" of rake). While hitched up to a trailer (usually 800 lbs or less tongue weight, occasionally more, often 4-500 lbs tongue weight), I don't mind getting closer to level, but still would like to maintain a bit of rake while towing. IME, it makes for a better towing experience. And the soggy diaper truck pulling a trailer look doesn't work for me.

This is why I was looking at the Dobinson spring pack: it appears that there are two overload springs - the first to possibly engage after that 700 lb limit is exceeded, the second to engage later with what I'm guessing would be around 1500 lbs load with a spring rate I'm guess close to stock overload. Guessing by the design, that overload won't engage until about 3" or so of suspension travel has been used up, or approximately 2100 lbs additional on the rear axle. That's all purely speculation, but I'd guess the method is correct.

However, it sounds like I'm being advised against them.

Why do I want to limit the the rear lift height to 1"??? Lots of reasons. First, I limited my front height to around 2" (wanted 1", but I was told no by Dobinson) but since I want to maintain some rake, 1" of lift in the back would give me a perfect rake as normally loaded with 2" of additional sag before leveling out the vehicle. Past 1" of lift in the back, the handling dynamics of the vehicle changes; I've run the bags with that additional lift to get to the sweet spot of cushiness, and it made a noticeable change in handling for the worse. I frequent a curvy highway road next to a reservoir; most of those corners and fun sweepers that can be taken at speed (except three - BELIEVE the 45 MPH cautionary sign on those ones...) but with just the additional inch of lift, I had to slow down 5-10 mph on the other corners. I run a TRD sway bar, as well, so I believe the additional height puts the bar out of it's most effective range and defeats much of what the sway bar is trying to do. Also, at 1" of lift, I get very good weight transfer front and back, side to side, so fast braking, fast accelerating, and general cornering feels very balanced. Believe it or not, I'm almost 50/50 weight balance with the truck as it sits (for those payload-averse in the crowd, don't bother doing the math..). Yet another reason - I like to run stock tires and wheel size; as small as the tires look, they look even smaller with a 3" level kit and 2" rear lift. As it is, it still looks well balanced to me. Smaller tires also weigh less, so braking, accelerating, and handling are better - to a point, obviously).

 

Blenton, I just started down this rabbit hole this week. I live in Boise so I went to Boise Springworks and chatted with them. Their suggestion was to add a couple leafs. They said it would raise the rear of the truck about 2". To counter that, I'm due for new shocks so they suggested Bilstein 5100's with the front strut on the top notch. That would give me the same stance I have now. He said he would suggest an alignment and gave me a place to call. I called the alignment guy and asked his opinion as well. He said Springworks was great BUT by having to put the 5100 on the top setting it would likely ride like a buckboard.

So, I'm back to square one. I'm going to put 5100's all around and keep my airbags.

 

Any reason not to just have stock height springs made that can handle the heavier load and then just do something like a coachbuilder shackle to get that 1” of lift?

 

Don’t disagree but another option. Plus the benefit of the beefier shackles.

 

I have considered it. I had CB +1 shackles for a while and they were fine; the hardware froze in the bushing sleeve after a couple of years and I had to get new springs when I tried to remove them to add the icon leaf pack after heat, hammer, sawzall and grinder options were exhausted. I never ran them without airbags so I don’t know if this is just old wives tales, but I’ve been told that heavy loads on taller shackles without taller bump stops will flatten and destroy the leaves faster. I’ve seen several posts in the past attributing flattened leaves at 50k miles or so to the taller shackles. Like I said, I don’t know it’s true or not, but that is what I have found.

And honestly, if I’m going to have a new leaf pack made, I will have it made up with the lift included. I don’t see any reason not to. Besides, those shackles ain’t cheap anymore! I mean, they weren’t cheap cheap when I bought them, but they’ve doubled in price since then. That’s just a lot of extra dough to spend on something that could have been built in to the springs for free, or next to nothing.

 

Thanks for the input. What kind of load do you usually have in your truck? Generally speaking, the higher the preload on the front coil, the harsher the ride can become, so they aren’t lying about the possibility of the ride becoming harsh. This is part of why I have avoided lifts over 2” and why I settled back on 1-1.5” if desired ride height. BUT, that also depends on the load and stance of the vehicle. If you only lift the front, it takes some of load off of the front end while empty and LOTS of load off the front end when towing or hauling, as you have a negative rake.

Depending on what is loaded in your truck and how, that can cause a rough ride. If the truck is heavy and you still have rake, it is less likely to cause a rough ride. Empty, though, and you have a good chance of that. From scouring the inter webs and judging by my own experiences, 2” of lift on the front is about as much as you want to go without sacrificing some ride comfort on a stock or empty vehicle.

That all said, I just ordered some 700 lb/in front springs to replace my 650 lb/in springs. 700 lb/in is the stock load rating. After weighing my truck, I managed to put a decent amount of weight on the front end so I’m going to go back to a heavier coil. This was very surprising as I only have a CBI skid and SC up front; the rest of the weight is literally on or in the bed. But it appears that I’m getting enough weight forward of the rear axle to transfer some to the front. I’ve always tried to keep weight forward in the bed and it appears to have paid off.

Was BSW going to add some leaves to your primary leaf pack, or install their 2nd stage kit? Just curious?

 

I’ll throw another one in to the mix - I forgot that General Spring made an HD replacement spring for not a lot of money. My only two questions are: how much are the springs rated for, and are they just the standard leaf pack with an add a leaf, or completely different springpack?


https://www.generalspringkc.com/2007-2018-toyota-tundra-heavy-duty-rear-leaf-spring-5-4-1-leaves/

 

Dobinsons plus sumo springs is a nice low maintenance option as well.