Do Shocks and Bars Matter for Towing? | Project Ford F-250

Update by Tom Suddard to the Ford F-250 project car
May 3, 2021

We’d been making fantastic progress outfitting our 2001 Ford F-250 to serve as the perfect tow vehicle. But each upgrade also added weight, and our truck was starting to show the strain.

It certainly wasn’t dangerous–turns out that doing the math and making sure we stayed within its factory ratings might not have been wasted effort, after all–but we knew every tow to the track would be much more comfortable with some suspension upgrades.

First, let’s define the problem: When fully loaded, meaning a slide-in camper and an enclosed trailer, our truck needed gentler inputs, and far more of them, than it did empty.

Picturing balancing a ball on your nose vs. rolling it on the ground, and you’ll have a working understanding of what our truck was like to drive loaded vs. empty. The air-filled helper springs fitted by the previous owner certainly assisted, but we knew we could do better.

Part of that was just simple physics: We were asking our chassis to operate near the limits of its design, and driving a big, top-heavy vehicle will always require a steadier hand than driving a Miata.

But we knew from past experience that a few simple upgrades could make our truck much more composed under load, so we rolled it into the shop and went to work.

 

Upgrading the Shocks on Our F-250

We wish we could say we used our extensive knowledge from racing to optimize our truck’s chassis to the nth degree. Yeah, uh, no.

Instead, we used our extensive knowledge driving old junk to realize on day one that our truck had four severely worn-out shocks.

How could we tell the suspension was underdamped? Simple: It. Just. Kept. Moving. Railroad crossings, pavement transitions, gusts of wind, pebbles: Almost anything seemed to send the truck on a wobbly journey as big oscillations gradually turned into small oscillations and finally tapered down to no oscillations.

Then the next bump started the process all over again. When empty, this meant a horrible, bouncy ride. When loaded, this meant constantly steering correction was necessary as the suspension kept bouncing around.

If anybody tells you, “That’s just how big trucks drive,” then slap that person and go buy some shocks anyway.

Sure, it’s true that our F-250 wasn’t built with track-ready handling in mind: Those solid axles mean it has a Miata-sized pile of unsprung weight underneath, and there’s three Miatas’ worth of body weight on top.

Those facts paired with the high spring rates necessary to haul a load mean we’d need trophy-truck sized (and priced) shocks to damp this suspension the way we’d like to if we were building a track car (Track Truck?).  

But F-250s like ours didn’t leave the factory with zero damping present. And because they’re so common, fresh shocks are inexpensive parts you should replace at the first sign of wear. Seriously, we found name-brand dampers for our truck for about $35 each, and installation takes about five minutes per corner.

We went as far as ordering those $35 shocks, then stepped back and thought it through a bit more.

We wouldn’t be caught dead on track with parts-store shocks. We put high-quality aftermarket shocks on everything we build. But we put way more miles on this truck than we’d ever put on the race cars, and even if it isn’t bouncing off curbs it’s still something that would benefit from better shocks.

This is especially true for our truck in particular, as those air-filled helper springs in the rear mean we’ve increased spring rate without increasing damping to complement it: A major no-no.

Hey, did you know Koni makes shocks for our F-250? Neither did we, but we found their new STR.T LT line listed at Tire Rack for about $70/each.

These aren’t the same Konis you’d put on your Miata: There’s no adjustment and they look and feel more like truck parts than car parts. But for the extra cost, they promise Koni build quality and more aggressive damping than the other options.

Sold. We changed plans and put those parts-store shocks back on the shelf. Installation took about 15 minutes on the ground; we didn’t even have to jack up the truck.

  

Adding a Rear Anti-Roll Bar to Our F-250

Worn shocks were certainly the lowest hanging fruit when it came to suspension improvement. But there was one more easy upgrade left to do: Add a rear anti-roll bar.

These are usually optional on ¾ ton trucks, and our F-250 left the factory without one. Why sell trucks set up like this? Because honestly, most trucks don’t need one. Thanks to stiff rear springs and a heavy front weight bias when empty, an anti-roll bar really doesn’t make much of a difference to the average truck buyer.

But we’re not average: We tow a heavy trailer while there’s a heavy slide-in camper in the bed, which means more rear roll resistance was definitely on the wishlist.

We thought about hitting the junkyard to find a truck like ours with the optional rear bar, but then we remembered we were working on a Ford truck, which means brand-new parts cost next to nothing.

Instead of crawling around on the ground hoping to find a bar, we ordered a brand new rear anti-roll bar kit from Addco. With a list price of $207.87, this kit includes the bar and all the mounting hardware necessary to install it on a truck like ours that didn’t originally have a sway bar.

At 1 inch in diameter, we’re pretty sure it lands somewhere between a stock F-250 bar and the monster fitted to F-350 duallies, so it should work fine for our application. We installed the sway bar while we were changing shocks, which added about 10 minutes to the job and didn’t require drilling any holes.

 

Driving Our New Tow Rig

After $500 in parts and 30 minutes of labor, we rolled the truck out of the shop and went for a test drive. And, yeah, we should have done this stuff the day we bought it.

The Konis made a night and day difference, and our truck went from stiffly sprung and miserable to just stiff. Even railroad tracks don’t scare us anymore!

But the real test wasn’t driving around in an empty truck: It was driving fully loaded, so we put the camper in the bed and hitched up our enclosed trailer. Had we tamed our truck’s wild manners?

As it turns out, yeah: We had.

That Addco bar significantly limits body roll, meaning we can now drive our truck and camper combination more quickly than we probably should.

We found ourselves needing to trail brake into our first cloverleaf off ramp. No, we didn’t go that fast on purpose: The truck was just so planted that we didn’t notice how close to the limits we were until we looked down at the speedometer.

And those new shocks mean that when we encountered uneven pavement or a bumpy bridge at 75 mph, there was no drama and nothing to worry about: Just leave the cruise control set and enjoy the ride.

Our truck was now driving better than ever, but there’re still improvements to be made. It’s time for some major surgery on the F-250; we’ll cover that in our next update.

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