Extended shackles vs lift blocks vs new springs

You've lifted the front of your ute, or you're about to, and now the back needs to come up to match. On a leaf-sprung rear there are three ways to do it, and they range from under two hundred dollars to well over a thousand.

The cheap options work, within limits. The limits are the part people skip.

First, why is the back low?

This question decides everything else. There are two different situations.

In the first, the ute sits fine and you just want it higher, to match a front lift or clear bigger tyres. The springs are doing their job.

In the second, the back has dropped because of weight: a canopy, drawers, a water tank, a towball load. The springs are overloaded or worn.

Shackles and blocks suit the first situation. Only springs fix the second.

Extended shackles

The shackle is the swinging link at the rear end of each leaf spring. A longer one lowers that end of the spring relative to the chassis, which raises the body.

ATI's extended greasable shackles have two mounting positions that give about 25mm or 50mm of lift, and they have grease nipples on the pins top and bottom. The serviceable pins are a real upgrade on their own, because factory shackles can't be greased and their bushes get noisy with age.

What to know:

• They keep the factory spring, so the ride stays much the same.
• They don't add any load capacity.
• A longer shackle tilts the axle slightly, which changes the pinion angle. At 25mm to 50mm that's rarely a problem, but a driveline vibration after fitting them is the sign to look for.

Kits are listed by vehicle, including the 2016-on Hilux, the Ranger and BT-50 and the 2020-on D-Max.

Lift blocks

A lift block is a machined spacer that sits between the axle and the leaf spring, held by longer U-bolts. The axle moves down by the height of the block, so the body sits higher.

ATI's lift block kits are machined aluminium in 25mm and 50mm heights and come with the extended U-bolts. As with shackles, the spring isn't touched, so the ride doesn't change.

What to know:

• They're the cheapest way to get a set amount of lift, and the lift is exactly the height of the block.
• They don't add load capacity either.
• A block moves the axle further from the spring, which gives the axle more leverage to twist the spring under hard acceleration or braking. That's called axle wrap. It's why blocks are kept short, and why you never stack them.
• Blocks are for the rear axle only.

There are kits for the Hilux, the PX Ranger and BT-50, the Next Gen Ranger and Amarok, the Triton, the D-Max and Colorado, and more.

New leaf springs

Replacement springs are built with a taller arch and a rate chosen for the load. They're the only option here that carries more weight without sagging, and they're the right answer for a ute with a permanent load or one that tows heavy.

They cost the most and take the longest to fit. Choose the rating honestly: a spring rated for 300kg of constant load will ride hard with an empty tray.

If your load comes and goes, an airbag load assist kit alongside the standard springs can be a better match than heavy springs you only need some weekends. It helps the springs when loaded and doesn't change your legal payload.

Side by side

Which should you choose?

For a lightly loaded ute that needs the tail brought up to match a front lift, shackles or blocks will do it. We lean toward shackles when the factory ones are old, because you get the greasable pins as well.

For a ute that carries weight all the time, buy springs. Lifting an overloaded spring with a block or a shackle leaves it overloaded.

Whichever you choose, check your brake hose length and your total lift against your state's rules afterwards. Our guide to what you need after a 2-inch lift covers the checks.

Common questions

Can I use extended shackles and lift blocks together?

It's possible, but the lift adds up and so do the side effects. Once you want more than about 50mm at the rear, new springs are the better way to get it.

Are lift blocks legal?

The ATI kits are described as ADR compliant within the height limits of VSB14, the national code for vehicle modifications. Your total lift still has to be within what your state allows.

Do extended shackles make the ride worse?

Not noticeably at these heights. With fresh bushes and greased pins, an older ute often rides more quietly than before.

Will these work on a coil-sprung rear?

No. Shackles and blocks are for leaf springs. Coil-rear vehicles such as the Navara NP300 need taller or heavier-rated coils.