It should come as no surprise that suspension parts, (i.e.: bushings, shocks, bearings, and wheel hubs) all need frequent maintenance. Unfortunately, this is often overlooked mainly due to the, “it’s working, so don’t mess with it” philosophy. But eventually, that mindset will definitely cause you to hear a noise or feel something strange happen from the front end of your ride.
Instead of waiting until something starts making noise or actually breaks, we thought it prudent to get some solid information about suspension maintenance and reached out to the folks at Strictly Diesel and MaxTrac Suspension about what to look for and even upgrade when it comes to the suspension under your diesel rig.
Rubber OE bushings might be okay when the truck leaves the factory, but how many miles do you have on your truck?
Let’s Talk OE Suspension Parts
While it was not planned for this article to take a GM focus, it just so happened when we hit up Strictly Diesel’s General Manager, Gary Maschner, he told us they had two Duramax trucks in for suspension work. That means we get to take a look at real-world wear on a GM suspension. All jokes aside, look anywhere on the internet, and it seems GM has been a focus for suspension failures — justified or not.
Maschner started by stating, “This picture [above] is a lower control arm bushing. OE bushings are no match for our dry climate and high summer temperatures, no matter what they’re made of. These are commonly the first bushings needing replacement and are very important as they can affect alignment.”
In the image below, you can see the yellow bump stop that has been worn away, an old shock that is worn out, and even though you can’t see how bad, the upper ball joint is also worn out.” Maschner continues, “Ball joints are probably the most commonly replaced suspension part we replace. They all wear out. Ball joints are not a part you want to go cheap on. Spend the money on quality parts that will last, especially on trucks that see any off-road use or have oversized wheels and tires.”
Diesel Army: What have you found are the most common wear items in a suspension?
Maschner:
“I’d say the most commonly worn suspension items we see include ball joints, shocks, and various bushings. Worn ball joints can be a major safety item if ignored for too long.” Many OE parts do not have a provision for adding grease so they cannot be maintained with any regularity. Aftermarket parts almost always have a grease fitting and making sure to keep the part greased will extend life.
Sulastic shackles are basically rubber isolators that take the heavy spring rate off 3/4 and 1-ton trucks when driving down the highway or city streets when not towing or hauling a load. In a way, these shackles are making your factory spring into a “progressive” style ride without reducing your spring weight capacity.
Let’s Talk Upgrades
Diesel Army: We understand these are trucks, but is there any way to get a better ride with your truck?
Maschner:
Improving ride quality can be done in several ways, and which way you choose depends on the truck. A good set of shocks will typically make a great improvement. I run the Bilstein 5100s on my LLY, and it rides great for a 3/4-ton truck. However, trucks with front leaf springs typically won’t have the smoothest of rides, and shocks will only do so much for them.
Adjusting your tire pressure when not towing can help as well. I normally run 65 psi up front and 55 psi in the rear when I’m not towing. There’s no need to run 80 psi in my rear tires without a trailer attached. However, you don’t want to run them too low as it can cause uneven wear.
Ball joints are typically one of the first suspension parts to wear out and need to be replaced.
If you have leaf springs on the rear of your truck another cool product is Sulastic shackles. I had them on my ’07 Duramax, and they were great and helped smooth out bumps and made freeway expansion joints less annoying.
Front coil springs are another area that can smooth out the front. For example, check out Thuren Fabrication springs. If it’s a torsion bar front suspension, then making sure the bars aren’t cranked up too high will keep it smooth and not feel jarring over speed bumps. In short, I typically suggest starting with shocks, adjusting tire pressures, and then adding other upgrades in steps from there.
Diesel Army: How do you help with squatting/sagging when pulling heavy loads?
Maschner:
Preventing the rear end from sagging comes down to personal preference and budget. I run a set of AirLift airbags on my Duramax. They give me adjustability for anything I’m hauling. An onboard compressor can be used to adjust the pressure but is not required. Other methods include a helper spring For these, check out Roadactive Suspension, or SuperSprings International Sumo Spring. Most of these methods will also help reduce body roll on trucks without a rear sway bar.
We also asked Jeff Simpson of MaxTrac Suspensions what he felt are the first common wear items on a high mileage truck that should be inspected right away.
Simpson:
All wear and tear items, including (ball joints, tie rod/drag link joints, wheel bearings, suspension bushings, and shocks) should be inspected frequently. If greasable suspension parts are used, they should be given a couple of pumps of grease every 5,000 to 7,000 miles.
Diesel Army:
If someone adds a lift, what changes can they expect from ride quality and load handling?
Simpson:
Our kits aim to achieve a ride quality as close to stock as possible. Although this is what we aim for, the new ride height and suspension range of motion are both huge factors in ride quality. Typically, when lifting or lowering a truck, you can expect a firmer than stock ride. On a lifted truck, this is how the lift is derived and creates more stability at the taller ride height. On the lowering side, a firmer ride helps keep the truck out of the bump stops since there is less suspension up-travel while also giving the truck better handling.
Most of our kits do not replace the factory springs, so the payload per what the springs can handle is not changed. When lowering, there is less suspension up-travel, so any suspension squat due to adding load can put a truck into its bump stops, so overload bags are always a good upgrade if planning on towing or carrying additional weight after lowering.
This is a torsion bar crossmember that rusted out and broke. “Fortunately for us here in the southwest, we don’t have to deal with rust, so this is not common. But for those that live in areas where it snows, it’s important to thoroughly inspect the underside of your truck from front to back,” Maschner explains.
Diesel Army: How do you recommend a customer decide what shocks they need?
Simpson: The decision of what shock to go with is ultimately up to the customer’s budget and personal preference. Our MaxTrac shocks are cost-efficient and reliable. Our Fox shock upgrade is more costly but aesthetically pleasing and offers a better quality ride. Our soon-to-be-released Vulcan Series 2.0 is the best of both worlds, offering a premium look and ride quality, but they are available at a more affordable price.
From the factory, trucks come with a slight rake as the front end is lower than the rear end. MaxTrac makes leveling kits for Super Duty (left) GM (middle) and Ram (right) to bring the nose up a couple of inches to create a level stance.
Diesel Army: What would you consider to be the first suspension upgrade a reader should consider?
I believe customizing and upgrading a suspension is a personal preference, so I cannot give a direct answer to this question. I can say that most customers are not happy with the factory rake of a stock vehicle, so a level stance is typically the first criterion customers are looking for. All of our kits, whether lift, leveling, or lowering, aim for a level or close-to-level stance.
Keeping It Together
We hope this short introspective about suspension parts helps you have a better understanding of how important regularly checking your suspension is. Doing so will make your diesel truck less prone to breaking parts and catastrophic failures. Likewise, if you constantly beat on your truck, parts will wear out much faster. So always keep that in mind when you put the suspension components of your rig under a high-stress situation.
