Going Undercover on Mitsubishi Undercar Service -

Going Undercover on Mitsubishi Undercar Service

Let's take look at the Mitsubishi line of cars and some of the more common problems you’ll see while investigating the undercar area.

0-opening-art--FrAt times, the life of an auto technician is much like a detective, as you look for clues to solve driveability issues. For this article, we’re going to take look at the Mitsubishi line of cars and some of the more common problems you’ll see while investigating the undercar area.

Since this automaker offers a solid vehicle lineup at a reasonable price, there are plenty of Mitsubishis on the road, and it’s safe to assume that they will find their way to a shop you will work in. And, there’s no reason they shouldn’t be welcomed.

The brake and suspension systems on Mitsubishi’s popular line of cars and SUVs are undercar systems where problems can be detected during routine maintenance.

From loose ball joints to worn-out brakes, it’s all there to be checked while the vehicle is on the rack for service and, oftentimes, the driver has no idea there’s a problem.

That’s why it’s so important that we recommend routine maintenance to our customers. Preventive maintenance not only helps your shop’s bottom line, but also lets the customer know that the safe operation of their vehicle is your primary concern.

Keeping Quiet
If the driver has a noise concern, many times, the best tactic is to have a tech road-test the car with the ­customer to help pinpoint the noise you’re chasing. At the same time, it’s a good idea to do a thorough safety inspection.0-23-Prototype-X-Action

As stated earlier, many times the owner is not aware that they have a worn suspension component, or need to have the brakes replaced. It’s up to us to point out these problems and advise the customer on the best course of action.

Get a Grip
Grab the wheel at the 9 o’clock and 3 o’clock ­positions and shake the wheel side-to-side, checking for looseness in the steering system. It doesn’t take a violent shake to feel the looseness, just a firm input. If you feel some play, have an assistant look for the movement, concentrating on the inner and outer tie rod ends, side movement of the ball joint, control arm bushings and wheel bearing play.

Move your hands to the 12 o’clock and 6 o’clock positions and do the same thing. Here you’ll pick up play in the strut shaft or mounting, ball joint and control arm bushing, and if there was any wheel bearing play in the shake test, it will also be noticeable. Finally, spin the wheel to check for noises and brake drag.

If play in the bearing is noticed, it should be taken care of whether it’s quiet or not. Check the torque on the axle nut; if it’s loose, you’ll have to make a judgment call — has someone been in there or is the ­bearing or hub showing wear? If the play is excessive, retorquing has no effect and the bearing isn’t ­growling, it would pay to be sure a hub is available before the car is disabled on the lift.

While doing your visual inspection, keep an eye out for rust around the mounting hardware. Where there’s rust there is movement, and where there’s movement there will be noise.

Suspension noises will usually present themselves in a couple of ways; knocking, squeaking and creaking are the most common. Squeaking noises are often the result of tie rod ends and ball joints binding up as a result of rust buildup. Tie rod ends can be checked with the car in the air by twisting the rod; ball joints can usually be confirmed with a knee to the bumper or rocking the vehicle side-to-side.

While you’re pushing, you can’t help but check the struts’ dampening condition, but it’s rare to have a noise caused by the strut itself. Using your technicians’ stethoscope, it’s not difficult to find the offending joint and don’t overlook the sway bar links.

Mounting Evidence
Many Mitsubishi models use ball-and-socket-type links that are also prone to the same type of failure and creaking noise. Like the tie rod end, a quick twist with the pliers should pick it up.

0-33-Lancer-Evolution-MRWe’ve had cases where putting the car up on a frame contact lift and allowing the suspension to droop, temporarily eliminates the noise.

Don’t overlook the sway bar and its attaching hardware. Any looseness here will result in a noise that is louder than you’d expect. Check the chassis mounting bushings by gently prying against the sway bar and look for any movement; there should be none.

Same with the links; any ­movement will result in a very noticeable knocking noise.

The only repair warning on the mounting bushings is to be ­careful when removing the bolts that secure the horseshoe bracket to the subframe. Don’t be stingy with penetrating oil and use heat, if necessary.

Breaking the bolts will turn a good job ugly in a hurry.

Removing the nuts on the links might be a challenge, as the rust on studs will cause the stud to spin. If faced with that situation, separate the joint exposing the ball end of the stud. A strike with a well-placed pry bar or air chisel is usually all it takes. With the ball exposed, grab it with a pair of locking pliers, making quick work of the replacement.

While doing your visual inspection, keep an eye out for rust around the mounting hardware. Where there’s rust there is movement, and where there’s movement there will be noise. When checking for tightness, always loosen the bolt, then retighten to the proper torque so you’re not tricked into thinking it’s tight, when it’s actually stuck in the threads.

Suspension Under Suspicion
There are some other common suspension issues that will drive customers to your shop, the most common of which are vibration, drifting or pulling complaints. If the tires are in poor condition or are mismatched, or if you notice excessive or uneven wear, suggest that they be replaced.

Like noise complaints, it’s always a good idea to road test vibration complaints with the customer because a vibration can be ­interpreted differently among ­customers.

Even after you ask all the right questions — When does it shake? Where do you feel it? Is it in the steering wheel, or through the seat, on the brakes, under load or while coasting? — there’s still a good chance for miscommunication, but a road test will help clarify things.

Since Mitsubishis have a FWD configuration, we have to keep in mind that axle problems will be presented as suspension complaints. The customer only knows that he/she hears a noise or feels a shake that seems to be coming from under the car.

That’s why the initial road test is so important.

When road testing, make note of when the shake occurs and how it reacts to driver inputs. If you can drive through the vibration, suspect a tire balance problem. If the vibration seems to change with the load, look for worn inner CV joints. On high-mileage cars, it can be difficult to pick out the offending joint. If both inner joints show excessive wear, the best course of action is to replace both.

Most poor-handling complaints will have the customer requesting a wheel alignment. Hyundai gives us very little alignment adjustment; on most models, only toe is adjustable. Of course, having the proper toe setting is important to handling as well as tire wear. But, it won’t usually change enough to cause a handling problem.

Ask if there were events that led to the car’s handling problem. Were the tires recently replaced or rotated, or did your customer have a flat repaired or put air in the tires? Here in the Northeast, suspension-damaging potholes are a very real threat, but it ­sometimes takes a reminder for the customer to relate them to their problem.

Handling complaints can vary, but most come down to the car doesn’t go straight or it wanders. The first place to look is at the tires’ condition and pressure. Don’t overlook tire sizing; it takes minutes to measure the circumference and the ideal situation is they’ll all match. But anything more than a 1/8-in. variance will cause a pulling problem. Wandering problems, caused by loose parts, should have been found during the initial inspection, but if nothing was found there, check the toe.

Squeaking By
Another undercar system that can be responsible for more noise complaints than the suspension are the brakes. Most complaints will be squeak-related, with the ­common metal-on-metal grinding taking a close second. Both of these noises relate to the pad.
The grinding noise is almost always the result of worn pads and the backing plate contacting the rotor, and we all know how to deal with that. To a lesser extent, you’ll also get some knocking complaints.


Squeaking can be the most ­challenging and is often evident after the brakes have been ­serviced. The best way to deal with brake squeal is to prevent it in the first place. While we’re all familiar with brake service, it never hurts to review good practices.

By now, I’m sure we’re all aware of the risk involved with pushing contaminated brake fluid backward through the anti-lock brake system. The risk of creating blockages in the ABS modulator is just too great to overlook. There’s really no reason not to open the bleeders and slowly retract the pistons, catching the bad fluid in your bleed bottle.

You’re going to bleed and flush the system as part of the service, so you might as well get rid of the most abused fluid right off the bat.

No matter where you live, there’s no debating that brakes live in a hostile environment that results in rust and corrosion that have to be taken care of to ensure a quality and quiet repair.
As the pads are being removed, it’s important to look for anything that isn’t moving freely and for pads that are worn evenly. Anything else indicates that the workload isn’t being distributed evenly and there’s a good chance that the pads are ­hanging up.

Up for Inspection
As the pads are being replaced, the system inspection should continue. Open the bleeder and push back the pistons on the calipers. On the front, we use a C-clamp between the outer pad and the back of the caliper. It should take little effort to retract the piston and move the caliper away from the outer pad.

If excessive effort is required, don’t force it; instead look for an indication of what’s binding and remove the caliper to further investigate. If the slides are frozen, it will be evident if the piston retracts easily with the caliper removed.

Make note if the pads are ­sticking in the carrier; either way, lubricate and service the sliders as well as the carrier. Be sure to remove the anti-rattle hardware in the bracket to clean the rust behind them; it’s that rust that will bind the pads, and any binding will result in noisy operation, as well as poor brake performance. When installing the new pads, be sure to lubricate any area where the pad contacts the bracket, and insulate the pad backing from the piston and caliper.

Squeaks are the result of the pads vibrating against the piston and bracket when the brakes are partially ­applied. If possible, always ­install new insulator shims with a little brake lube between the shim and the pad.

It’s always a good noise-­prevention practice to ­replace or machine the rotors when pads are replaced. Of course, we live in the real world and that’s not ­always possible. If you’re installing new pads against the old rotors, be sure the pads aren’t going to contact an area of the rotor that the old pads didn’t. In some cases, the unused area of the rotor can be cleaned up. In others, it’s best to advise the ­customer and note on the invoice that without replacing the rotors noisy operation is a possibility.

You’ll also see many of these cars equipped with drum brakes in the rear that will add to the noise issues. The most common is a grinding noise caused by ­accumulated brake dust that’s most noticeable when the vehicle’s driven after a prolonged stop. The debris will collect at the bottom of the drum causing a noise that will go away as the car is driven. The repair is as simple as cleaning the drums and brakes, and giving the system a good visual ­inspection.

Don’t overlook the hardware in that inspection. You can avoid a future noise complaint caused by broken hardware being ground up in the drum by identifying any bad hardware now. Another ­concern is a buildup of rust on the drum that causes interference with the backing plate. Depending on the extent of the rust, it can be cleaned off, but it’s often more cost-effective to simply replace the drums.

The last noise we’ll talk about is a knocking noise, and it’s caused by the brake pads rattling in the brackets. It takes very little movement to result in a fairly big noise.

Hitting the Road
Diagnosis is straightforward and can be performed on the initial road test.
As you’re driving over that potholed road, apply light pressure to the brake pedal; not enough to slow the car, but just enough to hold the pads tight.

If the noise is gone, you can bet the pads are moving. This driving scenario will also highlight any brake squeal noises you weren’t able to ­duplicate.

If the pads are moving, a hardware kit should provide you with all the parts you need to quiet the noise.

You May Also Like

Threadlocking Compounds For Vehicle Corners

To get the most out of these “liquid” tools, you first need to know how they work.

You might be seeing more blues, reds and various other colors on the threads of bolts when working on drivetrain, suspension and brake components. OEMs put these threadlocking compounds there for a reason, and not servicing them could get you into trouble. To get the most out of these “liquid” tools, you first need to know how they work.

Chassis Parts and Alignment Angles

Knowing why the adjustment is required is critical to performing the total alignment.

Ball Joint Inspection

It’s important to remember not to miss a worn joint. If a ball joint fails, the driver loses control of the vehicle.

Five Spark Plug Service And Replacement Tips

Most articles will tell you to use a torque wrench, but they never explain why.

Brake Rotor Quality Check

The brake rotor might look fine, but the problem could be internal.

Other Posts

Air Ride Suspension Diagnostics

The key to understanding the embedded logic of air ride systems is using service information.

Electric Power Steering Diagnostics

Load management for steering systems.

Steering Angle Sensor Service

Ninety percent of the time when a steering angle sensor code is active, it means the sensor needs to be calibrated.

Properties of Pistons

Pistons are perhaps one of the more sophisticated chunks of metal in the picture. Here’s what you should know.