AfterMarketNews AfterMarketNews Auto Care Pro AutoCareCareerHub Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service Speedville

Ford: Smoke From Vehicle When Starting

Vehicle: 2005 Ford Taurus SE, 3.0L Complaint: The customer says smoke comes from vehicle when starting. Cause: Confirmed the customer’s complaint and found smoke coming from the vehicle when the engine was started. Inspected the vehicle and found...

Read more...

R-1234yf Safety Procedure Checklist

Remember that R-1234yf is only mildly flammable. To become flammable, the mixture of air and refrigerant in a closed area like a vehicle cabin would need to be between 6.5% and 12.3% of the chemical vapor. This mixture must then experience a significant...

Read more...

Refrigerant Revolution: What R-1234yf Means for Service, Equipment, Safety

The new R-1234yf refrigerant is more than just a new jumble of numbers and letters on a label. For your shop, R-1234yf means several new procedures, a certification and new equipment in order to properly handle these new systems. Why the difference...

Read more...

Pontiac Grand Am: P0442, Replaced Gas Cap

Year: 2003 Complaint The customer states the check engine light is on. Cause Connected a scan tool and found code P0442 - Evaporative Emission System Leak Detected (small leak). Performed a visual inspection of the evaporative emissions system, but...

Read more...

Converter Codes: How Long Will the Light Stay Out?

A moral dilemma that many shops encounter on a regular basis: A good customer comes in with the engine light ablaze. Running the usual diagnostics, you encounter a catalytic converter efficiency code, a slow to respond oxygen sensor or some proprietary...

Read more...

Weak Air Ride Compressor Diagnostics

Air ride systems always used to have two diagnostic paths: either the vehicle was riding low or the compressor blew a fuse. Today’s modern vehicles have computer-controlled air ride units at all four corners that can pose a unique diagnostic challenge...

Read more...

Pinpointing the Source of Mercedes-Benz Fuel Leaks

If you’re paying attention, there are more and more European cars on the roads these days. And, if you’re doing repair and service on ­European vehicles, there’s a good chance you’ll see several Mercedes-Benz E-Class cars in your shop. Between...

Read more...

Engine Coolant Temperature Diagnostics

While old-school cooling system service often ­focused on coolant leaks and overheating engines, let’s begin thinking “new-school” by looking at modern cooling systems through the eyes of the engine coolant temperature (ECT) sensor. Coolant temperature...

Read more...

Volkswagen: Parking Indicator Sounds Off with No Obstacle

Customer complains that the parking assistance issues warning sounds for both the front and/or rear of vehicle with no obstacle in range. Water intrusion into sensor holders is causing corroded plug contacts and sensor electrical pins, which results in...

Read more...

The Right Diagnostic Tools Save You From Extensive Disassembly Time

By Andrew Shulgin, Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   A frequent reason for ­customers showing up at a vehicle repair facility is...

Read more...

Know the Specs for Your Social Media Accounts

By now, we should be well past the things I heard as recently as two years ago: “Social media is just a fad,” “No one will follow a (repair) shop on Facebook” and “I don’t care what you had for dinner, and I’m sure you don’t care where...

Read more...

MAHLE Service Solutions' New R1234yf Recovery Machine Named 'Best Use Of Technology' At MACS 2015

The ArcticPRO ACX1280 machine from MAHLE Service Solutions received the “Best Use of Technology” new product award at the 2015 Mobile Air Conditioning Society (MACS) Worldwide Trade Show. The award was selected by an impartial panel of automotive...

Read more...

Print Print Email Email

By Larry Carley
Technical Editor

Like brake pads, shock absorbers and tires, chassis parts wear out and eventually have to be replaced. But before you sell any chassis replacement parts, somebody has to discover the parts are worn.

Worn chassis parts can cause a variety of symptoms, including suspension noise, rapid or uneven tire wear, or a noticeable change in the way a vehicle rides, corners, handles or steers. If a vehicle has any of these symptoms, the steering and suspension should be carefully inspected to determine the cause.

A prealignment inspection is another time when many worn or damaged chassis parts are discovered. The chassis must be inspected because worn parts cannot hold the wheels in proper alignment.

WHAT TO LOOK OUT FOR
The technician doing the inspection should be looking for things like worn tie rod ends, loose ball joints, worn or deformed control arm bushings, worn or broken stabilizer bar links, sagging springs, loose or broken steering rack mounts, power steering fluid leaks, any play or looseness in the steering, and so on. Any problems that are found may have to be corrected before the wheels can be aligned.

Worn tie rod ends can be dangerous because a failure could cause a loss of steering control. Worn tie rid ends will also cause a rapid increase in toe wear on the front tires. The steering will also feel loose, causing the vehicle to wander at highway speeds. As a rule, tie rod ends should have no visible play when the steering is rocked back and forth.

Other items that may also have to be replaced include the inner tie rod sockets on rack and pinion steering gears, the rod adjustment sleeves on recirculating ball steering gear steering linkages, and maybe even the tie rods themselves. Replacing these items can make toe adjustments easier, especially if the old parts are badly rusted or frozen.

Another chassis part which is frequently replaced is the idler arm on rear-wheel drive vehicles that don’t have rack and pinion steering. The idler arm is a pivot point that helps maintain proper toe alignment as the wheels are steered.

A center link connects the idler arm to the pitman arm on the steering box, and tie rods on both sides tie the linkage to the arms on the steering knuckles. A worn idler arm will usually cause toe wear on the tires, as well as contribute to looseness in the steering.

Ball joints are another item that can be dangerous if they are badly worn. A ball joint failure can allow the suspension to collapse and also cause a loss of steering control. If a joint has more play than specifications allow, it needs to be replaced. Also if a wear indicator on a ball joint shows the joint has reached the end of its useful service life, it needs to be replaced.

On ball joints, acceptable play varies depending on the type of joint and vehicle. There are no standard rules of thumb.

Technicians should always refer to the wear specifications in a manual, and check ball joint play using the recommended procedure. Jamming a large crowbar between the control arm and knuckle and prying with all your might is not the way to check for wear. Pry hard enough and even a new joint may show excessive wear.

If one ball joint is worn or loose, the best advice is to replace the joints on both sides of the suspension (because both have the same mileage). The same goes for worn tie rod ends.

Tire wear, chassis noise and alignment problems can also occur if the bushings that locate the control arms are cracked, deformed or worn out. The bushings serve as the pivot points for the control arms, and most are made of synthetic rubber. Excessive compliance in the bushings can increase torque steer on front-wheel drive cars and minivans.

KEEPING IT STABILIZED
If a vehicle has excessive body sway when cornering, feels unstable in heavy crosswinds, or just does not handle well, the links and bushings for the stabilizer bar may be worn or broken. The stabilizer bar ties the left and right sides of the suspension together.

Most vehicles have a front stabilizer bar, and many also have a rear bar as well. When the body rolls, the twisting motion is countered by the stiffness of the stabilizer bar. If the bushings that hold the bar are loose, or the links on the ends of the bar are worn or broken, the suspension will feel loose and the body may experience too much roll.

On applications where the vehicle owner may want to improve handling, installing a larger diameter or stiffer aftermarket sway bar can make a noticeable improvement in cornering agility — without affecting ride harshness.

Springs are another item that are often overlooked but affect both wheel alignment and ride quality. Weak, sagging springs may allow the suspension to bottom out over bumps. Spring sag isn’t always obvious, so ride height needs to be measured to see if it is still within specifications. An inch or more of sag can place the chassis at or below its minimum ride height specifications, and cause undesirable changes in wheel alignment.

Springs may also need to be replaced to upgrade the suspension, too. If a vehicle is used for towing or hauling heavy loads, it might benefit from stiffer, stronger springs, or variable-rate springs. Any vehicle with a trailer hitch is a potential candidate for stronger replacement springs. A minivan is another vehicle that can often benefit from spring upgrades, typically variable-rate springs that don’t make the ride any stiffer, but increase the cargo carrying capacity for weekend projects.

HOW WORN CHASSIS PARTS AFFECT TIRE WEAR AND FUEL ECONOMY
When chassis parts such as tie rod ends, control arm bushings and ball joints are worn, it causes undesirable changes in wheel alignment that can increase tire wear dramatically and also reduce fuel economy. With gas selling for more than $3.50 a gallon in many parts of the country, who wants to waste gas?

Worn tie rod ends typically change toe alignment of the front wheels. Toe refers to the parallelism of the wheels. Both should point straight ahead when the chassis is properly aligned. This minimizes rolling resistance, which affects both fuel economy and tire wear.

Even a small amount of toe misalignment, say only 1/8th-inch, can increases the sideways scrub the tires experience as the roll along, causing them to wear much faster than normal. Only 1/8th-inch of toe misalignment will drag the tires sideways the equivalent of 28 feet for every mile traveled. The greater the misalignment, the greater the scrubbing and the faster the tires wear. Tires that might normally go 70,000 to 80,000 miles before they need to be replaced might be worn out in half that mileage if the toe rod ends are loose.

As a rule, all tires should wear evenly across the full face of the tread when wheel alignment is within specifications, the tires are maintained at the recommended inflation pressure, and the vehicle is driven sensibly.

Heavy outer shoulder wear on the front tires and/or a feathered wear pattern across the tread are classic symptoms of toe misalignment caused by worn tie rod ends. But camber misalignment can also cause shoulder wear on front or rear tires.

Camber is the vertical alignment or tilt of the wheels. Camber is measured in degrees from the vertical axis, and should usually be within a couple degrees of zero (perpendicular to the road). If camber differs more than about half a degree from one side to the other, it can cause the steering to pull to one side.

Underlying causes of camber misalignment include things like bent struts, misaligned strut towers (structural misalignment in the body), bent spindles, bad control arm bushings, and/or even weak springs.

Latest articles from our other sites:

Origins of the ‘Bendix’ starter

Every now and then you will run into an old-timer who uses the term “Bendix” in reference to the starter. You may think brakes when you hear this term, but there is some interesting history behind...More

GM: Eliminating Air Conditioning Odor

Models: 2014 and prior GM passenger cars and trucks Some customers may comment about musty odors emitted from the HVAC system at startup in hot, humid conditions. Cause This condition may be caused...More

Pontiac Grand Am: P0442, Replaced Gas Cap

Year: 2003 Complaint The customer states the check engine light is on. Cause Connected a scan tool and found code P0442 - Evaporative Emission System Leak Detected (small leak). Performed a visual...More

Converter Codes: How Long Will the Light Stay Out?

A moral dilemma that many shops encounter on a regular basis: A good customer comes in with the engine light ablaze. Running the usual diagnostics, you encounter a catalytic converter efficiency code,...More

Pinpointing the Source of Mercedes-Benz Fuel Leaks

If you’re paying attention, there are more and more European cars on the roads these days. And, if you’re doing repair and service on ­European vehicles, there’s a good chance you’ll see several...More

Engine Coolant Temperature Diagnostics

While old-school cooling system service often ­focused on coolant leaks and overheating engines, let’s begin thinking “new-school” by looking at modern cooling systems through the eyes of the engine...More

Jenny Products Offers Line of Electric Two-Stage Stationary Air Compressors

Jenny Products, Inc. offers a line of electric two-stage, horizontal-tank stationary air compressors. Ideal for applications requiring greater pressure, the line displaces between 9.1 and 107.0 cfm at...More

Oil Eater’s Tuff Rug Is Resilient In High Traffic Areas

The new Oil Eater Tuff Rug from Kafko International affords long-wearing durability for high-traffic areas such as maintenance departments. The absorbent pad provides safety by quickly soaking up oil,...More