Chinook E-350 4x4 swap

MoneyPit

New member
Im swapping my Chinook to a 4x4. So far i have a 2005 Dana 60 dually axle under the front using the Timberline Kit. I also install a new Hellwig swaybar, New endlinks, Reman steering box, New tierods, new draglink, new ford coil springs, Bilstein shocks, stainless brake lines, new brake pads, new calipers, etc.... I also eliminated the factory unit bearings using the Spyntec freespin kit. This kit made a night and day difference in the feel and drivability of this truck, highly recommend this swap regardless of whos kit you use. I also installed a Kelderman steering stabilizer kit.

I also used 2021 Dodge Ram 3500, 17 inch dually wheels. This required machining down the hubcentric shoulder on the dually adapters 1mm. Im ready to start on the rear end of the truck now and i am looking for opinions on who makes the best leaf springs to lift the rear of this heavy truck. I dont want to spend a bunch of cash on leaf springs just to have them start sagging a month after i install them.
Currently i have air suspension on the back with spacer blocks but i want to go back to leaf springs.

I considered using a shackle flip kit and utilizing factory ford springs to lift the rear, but im looking for maximum ride quality and i dont think the flip kit is the answer.
 

Attachments

68camaro

Any River...Any Place
Im ready to start on the rear end of the truck now and i am looking for opinions on who makes the best leaf springs to lift the rear of this heavy truck. I dont want to spend a bunch of cash on leaf springs just to have them start sagging a month after i install them.
Currently i have air suspension on the back with spacer blocks but i want to go back to leaf springs.

I considered using a shackle flip kit and utilizing factory ford springs to lift the rear, but im looking for maximum ride quality and i dont think the flip kit is the answer.
I I have a lifted 2wd Chinook with 4.5" front lift and used 2 inch blocks in rear plus raise MorRyde to get even, but after two years it has dropped in rear quite a bit. My rear axle is 7,200 which puts whole rig at 10,700 fully loaded which is 200 over max. I am looking to add 5" in rear & wondering the same things. My preference is to remove blocks and just go leaf spring.

However, I wasn't aware sagging with leaf springs is a real concern? Don't they use these on heavy duty trucks, dump trucks etc...way heavier than our Chinooks? I was looking at atlas springs (http://atlassuspension.com/) or local to make custom, Monday I will discuss with local guy. Atlas running 2-3 months but could be sooner, but like everyone their supply chain slow. Atlas was very helpful to talk to and not rushed.

I wonder if shackle flip is bigger question, the flip and shackles aren't cheap and if they do not work money may have been spend better towards leaf springs, but no idea if true.
 

MoneyPit

New member
Generally speaking heavy trucks like those use air suspension versus leaf springs. The sagging comes from the added arching of the spring required to give your vehicle that added 5 inches of lift. The trucks that do use leaf springs dont
have that kind of lift or arch to the springs and the springs they do use tend to be pretty stiff giving a less than quality ride. Its a coin toss really, thats why i posted asking for input from others who have already spent the cash for springs.
 

BritKLR

Kapitis Indagatoris
Beautiful rig! Awesome build. Kinda apples and oranges since our Tiger is on a IFS K2500 chassis but, my only observation is the front steering stabilizers. Depending on where you take your rig they maybe susceptible to damage. Pick a good line and shouldn't be an issue. Goodluck on your build!
 

68camaro

Any River...Any Place
My rear axle is 7,200 which puts whole rig at 10,700 fully loaded which is 200 over max.
Correction my GVWR is actually 10,700 not 10,500, so fully loaded (including 489lbs of water and gas) I am right at max.

When ordering leaf springs do people use max weight or does it make sense to back off some for gas and water usage (reduction) while on trip, or does it even matter?
 

marret

Active member
Don’t know about others, but I went with max weight and a few years later am glad I did. I think your use impacts the decision. I have progressive springs and feel the extra capacity is worth it. Don’t think I would notice the difference as we are only talking hundreds of pounds.
 

MoneyPit

New member
You should use your fully loaded weight when ordering springs, fill up with gasoline, propane, water, etc.... I tossed in all of the items i would normally carry in the rig as well, including my Dog, then we headed for the CAT scale.
You need to know what the vehicle weighs loaded, otherwise its pointless and you might as well just throw them a random weight number.

My Chinook new was rated at 10,400 pounds dry, meaning no water no nothing inside. I put a dana 60 under the front and all of the corresponding hardware that goes with that swap. That swap added 100's of pounds of unsprung weight to the vehicle versus the two I-beams i removed. The dually dana 60 front axle alone weighs right around 500-600 pounds. Im not sure how to break all of it down in terms of sprung versus unsprung weight, since unsprung weight plays no role in how much weight is on the springs.

Follow me? Lets say my rig weighs a total of 10,500 pounds. That weight includes water, fuel, tools, clothing, dogs etc.... But it also includes a certain amount of unsprung weight, such as 1100 pounds of front and rear axles, wheels, tires, shocks, rotors, calipers, etc....
 
Last edited:
Top