If you're looking into a 5th gen cummins lifter conversion, you've likely realized that the factory hydraulic setup isn't all it's cracked up to be. When Ram updated the 6.7L Cummins in 2019, they made a massive change that ruffled a lot of feathers in the diesel community: they ditched the traditional solid lifters and went with a hydraulic system. On paper, it sounded like a win. No more valve adjustments every 150,000 miles, a quieter engine, and a more "refined" driving experience. But for those of us who use our trucks as trucks—towing heavy, adding power, or just expecting that legendary Cummins longevity—the reality has been a bit different.
The truth is, those hydraulic lifters have become a significant weak point for many owners. Whether it's a mysterious ticking sound at idle or a catastrophic failure that sends metal through the engine, the 5th gen lifter situation is something you can't really ignore if you plan on keeping your truck for the long haul.
Why the factory hydraulic lifters are a problem
The move to hydraulic lifters was mostly driven by emissions and the desire for a quieter cabin. In an older Cummins, you have that iconic mechanical "clatter." That's the sound of the overhead valves having a tiny bit of clearance, or lash. In the 2019+ models, the hydraulic lifters use oil pressure to automatically take up that gap. It makes the engine run smooth and quiet, but it introduces a lot of complexity.
The big issue is that these lifters are prone to bleeding down or failing to pump up correctly. If you've ever started your 2019+ Ram and heard a loud tapping that eventually goes away (or doesn't), you're feeling the pain. Even worse, if a lifter fails completely, it can damage the camshaft lobes. Once that happens, you're not just looking at a simple fix; you're looking at a full engine teardown. This is why a 5th gen cummins lifter conversion has become one of the most popular reliability mods for these newer trucks.
What does the conversion actually do?
Essentially, a 5th gen cummins lifter conversion backdates your valve train to the older, more reliable mechanical style. You're essentially swapping out those finicky hydraulic units for solid lifters. It's like going back to the basics—back to what made the Cummins famous in the first place.
When you do this conversion, you're eliminating the variable of oil-pressure-dependent lifters. Solid lifters don't "collapse." They don't care if your oil is a little cold or if you're pushing 60 psi of boost. They provide a direct, mechanical link between the camshaft and the pushrods. This means your valve timing stays consistent, your engine can handle much higher RPMs, and you lose that "ticking time bomb" feeling in the back of your mind.
What's included in a conversion kit?
Usually, if you buy a complete kit for this, you're getting more than just the lifters. Since the height and travel of a solid lifter are different from a hydraulic one, you can't just swap the lifters and call it a day. Most kits include:
- Solid Lifters: These are the heart of the swap. They're usually made from high-grade tool steel and are designed to handle much more abuse than the stock parts.
- Adjustable Pushrods: Since you're going to a solid setup, you need a way to set the valve lash. High-quality heavy-duty pushrods are a must here anyway, as the stock ones are notoriously thin.
- A New Camshaft: In many cases, it's highly recommended to swap the cam at the same time. The lobe profile for a hydraulic lifter is different from a solid lifter. While some guys try to reuse the stock cam, most reputable shops will tell you to put in a "drop-in" mechanical cam to ensure everything wears correctly.
The performance benefits of going solid
While most people do a 5th gen cummins lifter conversion for reliability, there are some serious performance perks too. If you're planning on adding a larger turbo, bigger injectors, or a custom tune, the hydraulic lifters are going to hold you back. They tend to "float" at higher RPMs, which means the valves don't close exactly when they should. This leads to a loss of power and potential engine damage.
With solid lifters, you have total control. The valve train becomes much more stable. If you're building a high-horsepower street truck or a dedicated towing rig, that stability translates to a broader powerband and better throttle response. Plus, let's be honest, most Cummins owners actually miss that mechanical sound. After the conversion, your truck will sound like a real diesel again.
Is the installation a DIY job?
I'll be straight with you: this isn't a project for a Saturday morning in the driveway with a basic socket set. To get to the lifters on a 6.7L Cummins, you have to pull the cylinder head. That's a lot of work. You're looking at disconnecting the fuel system, the cooling system, the turbo setup, and then lifting a very heavy head off the block.
Because the head is coming off, most people take the opportunity to upgrade their head studs at the same time. If you're already in there, it's a no-brainer to toss in some ARP studs to prevent head gasket issues down the road. If you aren't comfortable timing an engine or pulling a head, this is definitely a job for a professional diesel shop.
The trade-off: Valve lash adjustments
The only real "downside" to a 5th gen cummins lifter conversion is that you're bringing back a maintenance item. With solid lifters, you have to manually check and adjust your valve lash every so often. Most guys check them every 30,000 to 50,000 miles just to be safe, though many find they don't move much after the initial break-in.
Is it a bit of a hassle? Sure. But compare a couple of hours of maintenance every few years to the cost of a catastrophic engine failure because a hydraulic lifter decided to quit on the highway. Most of us would take the manual adjustment any day of the week. It's a small price to pay for the peace of mind that comes with a bulletproof valve train.
Making the decision
If your truck is bone stock, you have low miles, and you don't hear any weird noises, you might be tempted to leave it alone. And hey, some people go 200,000 miles on the hydraulic setup without a single hiccup. But if you've already started hearing that dreaded tick, or if you're planning on turning up the heat with some performance mods, the 5th gen cummins lifter conversion should be at the top of your list.
It's one of those "do it once, do it right" kind of mods. It fixes a fundamental design flaw and returns the Cummins engine to its roots. You'll get a truck that's more reliable, sounds better, and is ready to handle whatever you throw at it. In the world of diesel performance, there aren't many mods that offer that much value across the board. If you're planning on keeping your Ram for a decade or more, this is probably the best investment you can make in the engine's future.