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LML Duramax Problems

What are common LML Duramax problems? Find out here!

Common Problems found on LML Duramax Trucks & Solutions

LML Duramax Suspension & Steering Problems

The independent front suspension on the LML Duramax provides an excellent ride, but it leaves much to be desired as far as longevity is concerned. Many of the steering and suspension components aren’t up to the task of larger tires and aftermarket wheels. Steering component durability isn’t just one of the LML Duramax trucks problems, it’s an issue across the board on all Duramax trucks including the LB7, LLY, LBZ, LMM, and L5P. Cognito and Kryptonite are two well known and respected companies that offer solutions to all of the LML Duramax steering and suspension problems.

Weak Tie Rods

Have you ever looked at your factory tie rods? Weak is an understatement! Duramax trucks are notorious for breaking factory tie rods. You can strengthen the OEM tie rods by adding tie rod sleeves. If your tie rods are already worn out, replace them with aftermarket ones! Cognito and Kryptonite both make replacement tie rods that are vastly stronger than their oem counterparts.

Ball Joint & Upper Control Arm Problems

If you leave your truck stock, you likely won’t need to replace your upper control arms or ball joints. When you crank the torsion bars, you increase the stress put upon your ball joints and other front-end components. This throws factory steering geometry out of whack. Aftermarket upper control arms help bring factory steering angles back while also bringing back factory ride quality. Longer shocks also improve ride quality. Cognito and Kryptonite both offer bulletproof UCA kits. I prefer Kryptonite as they offer a lifetime, no questions asked warranty on all of their products.

Pitman/Idler Arms

Worn pitman and idler arms can cause irregular and early tire wear. They’re often the cause of broken tie rods! By adding pitman/idler arm support brackets, you can extend the life of your front-end components! Kryptonite and Cognito also offer kits to support these components! They even offer replacement Pitman and Idler Arms that are much more durable than the OEM components!

Injection Pump Failures

The Bosch CP4.2 injection pump on the LML Duramax is coined a “Ticking time bomb” by many people familiar with the LML platform. It’s extremely susceptible to failure from bad diesel fuel or lack of lubrication. When it breaks, it often takes the injectors out with it. The LML Duramax also didn’t come with an OEM lift pump! This means the injection pump has to work extremely hard to supply the engine with fuel. This is why we recommend an aftermarket lift pump from Fass or Air Dog. The use of an aftermarket fuel filtration system and lift pump can help prolong the life of the injection pump and also improve fuel quality. The only complete solution to the problem is by replacing the CP4.2 with an aftermarket injection pump. You can find out more about the new fuel system on our LML Duramax Specifications page.

LML Duramax Emissions Problems

Although emissions are necessary on diesel trucks today, they frequently cause issues, especially when they are first released. LML Duramax emissions included a new Selective catalytic reduction system. Early LML Duramax trucks 2011-2012 have well-documented issues with Nitrogen Oxide (NOx) sensors that are a part of this SCR system. Other issues have also occurred regarding the DEF system. Emission repairs are often expensive! Replacing the DPF alone can cost thousands of dollars!

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Founder of Diesel Resource and a complete diesel head. Has a little bit of problem buying too many trucks. Learn more about him by checking out his truck.