Refining a British Tractor - BP51’s on the TD5

OME BP-51

Taming the Washboard Roads: Fitting ARB BP-51s to the Trusty TD5

There is an undeniable, rugged romance to the Land Rover Defender TD5. It’s a vehicle that looks like it belongs on the Serengeti or crossing the Simpson Desert, even when it’s just parked in the driveway. But any seasoned overlander knows the harsh reality beneath the romance: taking a fully loaded, solid-axle Defender over thousands of kilometers of corrugated dirt is a surefire recipe for spine realignment.

After our last trip through the red dust of the Cape, where the dashboard felt like it was trying to vibrate itself into a parallel dimension, and all the while thinking the roof was going to un-bolt itself, I knew something had to change. The landscape was breathtaking, but I was somewhat too busy gritting my teeth to enjoy it.

Fast forward a few weeks, back home on the Sunshine Coast now, next on the to-do list, stopping in and talking to the team at ARB Caloundra. Having a little poke around the suspension wall, the BP51 gear stood out, and why wouldn’t it, look at those beautiful pieces of automotive art. So after a little (a lot of) homework and research was had, consisting mostly of product videos, YouTube reviews, some blog reading etc, I think my mind was made up…

The good, the better and the best!

With a few emails back and forth, a price was set, and a deposit paid … Enter the ARB Old Man Emu BP-51 High-Performance Bypass Shock Absorbers.

This isn't just a suspension upgrade, to me and my evidence backed research (and deep inability to talk myself out of buying them), this was an investment. One I was Very excited for.

Here is the story of how we brought 21st-century damping technology to our classic British tractor, in preparation for the jam packed tour, recon, data capture, and travel schedule ahead.

The Anatomy of the Upgrade

Before we get our hands dirty, let's talk about why I chose the BP-51s. As a traveler, I don't want to think about my suspension; I just want it to work. But the engineering here is worth appreciating.

Unlike a standard shock absorber that forces oil through a single piston, the BP51 "Bypass 51mm" allows fluid to bypass the piston entirely during normal driving, providing a plush ride. When you hit a massive washout or a brutal rut, the bypass channels taper off, forcing the fluid through the piston and stiffening the shock to prevent bottoming out.

The Travel Translation: It rides like a luxury SUV on the highway, but eats up catastrophic potholes on remote tracks without breaking a sweat.

Add to that the remote reservoirs and independent adjustability for both rebound and compression, and you have a system tailored for varying travel loads—perfect for when the water tanks are full versus when we're running light on a weekend trip.

The ultimate value of OME suspension isn't that it is completely unbreakable; it's that when an issue arises in the middle of nowhere, ARB will support their customers to get them back on the road, and on with their adventure with minimal fuss. After suffering failed suspension components from other name brands I’ve used, and receiving the generic “send it back for inspection, so we can consider sending a replacement” it just doesn’t cut it any more. As a frequent traveler, this type of peace of mind is worth every penny.

The Shed Sessions: Installation

You don’t need to be a master mechanic to install these, but fitting anything to a TD5 that’s seen a few decades of mud requires patience, a hefty breaker bar, and perhaps a few cold beers. Or do what I did and hand the keys over to British Offroad to work their magic while I keep the GO4×4 admin wheels turning.

1. The Tear Down: Removing the old, tired coils and shocks was an exercise in archaeology. Years of hardened red dirt had to be wire-brushed away, with some bolts needing a little persuasion from the cutting disc. Tip: Soak your shock tower bolts and lower mounts in penetrating fluid the night before.

2. Routing the Reservoirs: The BP-51s are pieces of anodized aluminum art, and it almost felt wrong to put them in the dark, dusty wheel wells. The trickiest part of a remote res suspension install on the Defender is mounting the remote reservoirs, but not for the Old Man Emu kit. ARB provides vehicle-specific mounting brackets, which in the TD5's case, bolt neatly to the spring top and Chassis, coated in a quality black powder coat. 

The Fresh Install.

3. Springs and Shocks: With the Defender up on the hoist and the axles drooped, slipping the new Old Man Emu coils in was straightforward. Pushing the beefy 51mm shock bodies into place took a bit of wrangling, but everything bolted up with ARB's typical precision. Might I add the spring design and length at full extension is spot on for the Defender, even doing away with my old coil spring relocation cones. 

4. The Initial Setup:

We set the compression and rebound to the factory-recommended baseline. Adjusting the BP-51s requires slipping the provided C-spanner onto the ribbed collars on the shock body. While it takes a minute longer than a simple finger dial, the firm smooth pressure to rotate the dial assures you that the setting won't budge, no matter how harsh the outback roads get.

The Shakedown and the Ultimate Test Ahead

The true test of the BP-51 wasn't in the shed; it was during the initial shakedown runs through the local hinterland, all in preparation for this year's massive expedition up to Cape York.

The Highway Transit:

Immediately, the TD5 felt different. Whilst as expected it wasn’t a race car on rails, it still felt controlled yet plush. After a few tweaks, the highway ride was dialed in, and we were on our way. On the fresh springs, new shock absorbers, the truck was tall. It now had a presence about it, looking as tough as a Defender should look.

The Local Corrugations:

When the bitumen ended and the local forestry washboards began, the transformation was nothing short of miraculous. Where previously the tyres would skip and chatter across the ridges, causing the whole vehicle to drift, the BP-51s kept the rubber glued to the dirt. I found myself comfortably cruising over tracks that used to rattle our teeth. But not just the corrugated roads, the back tracks, potholes and small washouts were nothing now, and you find your cruising speed is now faster than usual yet remaining comfortable. What about potholes? The last minute potholes, that look deep and jarring, the ones you only hit because their depth and severity are obscured by fading light or the moving shadows of a breeze tickled canopy. Those pot holes are no longer as heart sinking or teeth gritting, thanks to the new bypass technology. A perfect example of not needing to worry about what your suspension is doing, just knowing it will do it’s thing when needed is a relief in itself.

The new suspension keeps the Defender cab very level over un-even ground.

Ready for the Cape:

The real magic of this kit will shine later this year when we finally hit the Tele Track. Halfway through our Cape York trip, as our load lightens, water tanks empty, and supplies dwindle, I know exactly how i'll adapt. We'll be able to pull over under the shade of a stringy bark, grab that C-spanner, and dial back the compression on those ribbed collars to bring the plushness back to the lighter truck. It is this adaptability that makes the kit an overlander's dream.

the 2025 trip, running on the old suspension. Can’t wait to try the new gear out.

Final Thoughts

At a premium price point, the ARB BP-51 kit is an investment. It’s hard to justify if your 4wd only sees weekend trips to the local beach. But if you are a traveler whose soul belongs to the long, unforgiving roads that stretch out beyond the horizon, this suspension kit is worth its weight in gold.

It didn't just change the way the Land Rover drives; it's about to change the way we tackle the Cape. I plan to arrive at camp less fatigued, less beaten up, and more ready to appreciate the wild far-north places we've driven so far to see.

The Every Day BP51 Settings for the Defender 110:

Currently with a medium load out -

Front - C4, R6

Rear - C5, C7.

Check Back here after the Cape and I we will see what my loaded long term travel setting is, or how much I have needed to change it.