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Stemco Wheel BearingsTractors and trailers exposed to water submersion require special consideration to be given to the work procedures used in salvage and/or rebuild of the units. STEMCO does not recommend putting any unit into service that has not had a complete wheel end inspection and/or repair as described below. If wheel ends are not properly repaired, wheel end performance may degrade, up to and including possible catastrophic wheel end failure.


CAUTION While handling units which have been submerged in flood water, caution should be taken to protect technicians and the environment. With these units exposed to flood waters of unknown chemical composition, STEMCO recommends:

  • Technicians wear personal protective equipment (i.e. face, hand, protective body equipment, etc.) while exposed to contaminated wheel ends.
  • Consultation with local EPA officials regarding proper handling and disposal procedures for the contents of contaminated wheel ends. All hazardous waste from affected wheel ends should be disposed of per EPA requirements.

1. Identify Wheel End Type and Conditions

  • Is the wheel end equipped with Sentinel hub cap technology? Refer to #3 or #4 below.
  • Is the wheel end lubricated with oil or grease?
  • Does the wheel end contain a pre-adjusted bearing package? Some pre-adjusted wheel ends have limited rebuild capabilities. If you have this type of wheel end, contact the pre-adjusted wheel end manufacturer for rebuild instructions.  

    NOTE: Water, especially salt water, is corrosive to wheel ends and may degrade lubricant and metal components

2. General Steps

  • Inspect all wheel ends, not just a random sampling.
  • Clean the exterior of wheel end, washing off potential chemical or other contamination in a location with approved drainage and run-off collection capabilities.
  • In all cases where the lubricant is drained or removed from a wheel end, properly dispose of that lubricant. Disposal may differ depending on level and type of chemical contamination in the lubricant.

3. Sentinel Type Hub Cap
STEMCO offers hub caps with Sentinel technology (Sentinel hub cap and ESP plugs). These products provide water resistance to the internal hub cavity via a filter membrane. It is identifiable by the word "Sentinel" written on the non-removable red plastic cap or "ESP" on the blue removable plug. Wheel-ends equipped with Sentinel technology are likely to have little, if any, contamination inside. However, under these extreme conditions, all wheel ends should be inspected using the following procedure.

  • Remove the hub cap.
  • Oil Lubrication - Drain the wheel end lubricant into an approved receptacle.
    • Inspect lubricant for water contamination, dispose of lubricant properly.
    • If no lubricant contamination is found, install the hub cap with a new gasket and refill to the proper level. (Refer to TMC RP 631B)
  • Grease Lubrication - Follow the recommended annual inspection procedure for grease wheel ends (Refer to TMC RP 631B). This involves removing the outer bearing and inspecting the hub cavity for proper lubricant level and condition.
    • If no contaminants are present assure proper grease level and reassemble. (ref: TMC RP 631B)
    • If the lubricant is determined to be contaminated, follow the complete disassembly practice listed in #4.

4. Non Sentinel Type Hub Caps
Other hub caps may not provide the same level of water resistance and, when submerged, it is likely that contamination will enter the wheel end. NOTE: Tire inflation systems hub caps in many instances look like the Sentinel system. These do not contain Sentinel technology. Treat these as you would a non Sentinel hub cap as described below.

  • Remove the hub cap.
  • Drain wheel end lubricant (OIL or GREASE) into an approved receptacle. Dispose of properly.
  • Disassemble the wheel end.
  • Inspect the bearings and races for any signs of rust or discoloration. If there is any sign of rust or pitting, both the BEARING AND THE CUP HAVE TO BE REPLACED.  Shop here for replacement wheel bearings.

    NOTE: On aluminum hubs, a special procedure is used to install bearing cups. Refer to the hub manufacturer for their recommended procedure.

  • Inspect the axle and hub for any signs of rust or discoloration. If rust is present, clean the surface with emery cloth to remove rust.  

    NOTE: This is especially important on the axle bearing journals and seal shoulder and in the hub bearing and seal bores.

  • Clean all components to be reused in solvent and properly dry these parts.

    NOTE: Never use compressed air to spin the bearing as this can cause injury to the technician and/or damage to the bearing.

  • Lubricate bearing rollers and axle with the same type lubricant (OIL or GREASE) to be used in the hub.
  • Reassemble the wheel end using proper assembly procedures.
    • Refer to TMC's RP 618B for bearing adjustment. NOTE: Verify that wheel end bearing adjustment is 0.001" to 0.005" end play using a dial indicator.
    • Refer to TMC's RP 631B for lubricant fill procedures.
    • Installation instructions reference material is available at www.stemco.com. Or call STEMCO at 1-800-527-8492. Ask for technical support.

**Tech Tip Provided by STEMCO.  

Posted By Class8TruckParts.com

Diagnosing Starter Cranking Problems

Jul 21, 2017 11:15:49 AM

Are cranking problems frustrating your fleet?

While cranking problems can be frustrating, identifying and correcting the root cause doesn’t have to be. The first step is to identify the symptoms. In a cranking system, you can divide your symptoms into one of three possible troubleshooting categories:

  • Slow Crank: The starter will crank, however, the engine RPM is slow to start the vehicle."REMY_STARTER_VOLVO_INPOST
  • Click No-Crank: The solenoid clicks but the starter doesn’t crank.
  • No-Click No-Crank: The solenoid doesn’t click, and the starter doesn’t crank.

Once you have identified the problem you’re dealing with, then you can start to remedy it. For all issues, the initial troubleshooting is the same – you start with the batteries.

STEP 1 – Begin at the batteries: Charge the batteries and perform a battery load test on the battery bank. If the load test fails, then individually test each battery and replace any faulty ones.

STEP 2 – Perform a voltage drop test: Once batteries pass muster, then perform a voltage drop test on the starter main cables. The starter voltage drop should be less than 0.5V drop total on cranking circuit. This is an important step and is often the cause of a slow cranking complaint. Yet, voltage drop also is a leading cause of click or no-click complaints because almost every vehicle manufacturer uses the heavy positive post, located on the starter solenoid, as a place to pick up the current used to supply the control circuit.

STEP 3 – Identify the specific issue: Until now, the diagnostic path has remained the same regardless of the complaint. Now is where you address the specific issue.

  • Slow Cranking: For the starter to crank, the control circuit would have to be working. So, if battery and cable checks are within specification and the vehicle still cranks slowly, then it’s a slow cranking problem, and it’s time to replace the starter.
  • Click No-Crank: Check the control circuit. If the starter does not contain an Integrated Magnetic Switch (IMS), then a voltage drop test will need to be performed on the vehicle control circuit. If the starter has an IMS switch function, the technician will have to verify that the vehicle’s control circuit is providing voltage to the starter IMS.
  • No-Click No-Crank: When this occurs, power is not being sent to the solenoid, making it very unlikely that the issue is related to the starter motor.

If all systems have been checked, and the starter is found to be the cause, the ring gear should also be inspected for damage that could cause future starter damage.

View Remy’s step-by-step video on “Diagnosing Starter Cranking Problems.”

If you need to replace your starter, check out our selection of Delco Remy Heavy-Duty Truck Starters

Posted By Class8TruckParts.com


Broken lights are among the most visible of all Compliance, Safety, Accountability (CSA) violations and can result in a loss of up to six severity points in CSA for each violation.

Watch the above video on what enforcement officers look for during an inspection, the consequences of non-compliance and how you can prevent lighting-related CSA violations.

If you need lights for your truck, check out our selection of truck lights from Truck-Lite and Grote

We also recommend these CSA Lighting Kits from Grote and TrucK-Lite

Posted By Class8TruckParts.com

Summer Maintenance Tips

Jun 8, 2017 11:18:39 AM

Hot summer weather is coming soon. While many of us will relax outside a picnic, or visit the beach because of the warm weather, don't forget about maintenance you need to perform for your truck for the hot weather.Volvo Truck Summer Clouds

Most people forget to prepare their truck for the hot weather, even though they remember to winterize their truck. Preparing for the hot summer weather can be critical to ensure you don't experience unexpected downtime.

We recommend the following checks:

  • AC System - While this seems obvious that you want your AC system to work properly in the summer, A lot of people assume if the truck is blowing cold air that everything is ok.  We recommend ensuring your AC condenser is cleaned.  Ensure there is not dust or debris covering your condenser.  Also, check your cabin air filter, a restricted cabin air filter can force your system to work harder than necessary.  
  • Batteries - Hot summer weather can actually cause more damage to batteries than cold weather.  Inspect your battery cables for corrosion and clean these connections.  Inspect your batteries for cracks, or bloating.  If possible, load check your batteries to verify if they need to be replaced.
  • Tires - Hot summer weather can cause tires to wear quickly.  Verify your tire pressure is correct (not under, or over inflated).  Check the tire wear to ensure they are wearing evenly.
  • Belts and Hoses - The hot summer weather will give your truck's cooling system more work.  Inspect your hoses for any issues.  If the hose has any deformities or cracks, consider replacing them.  Check your belts that they are aligned properly on the pulley, and have proper tension.  Check your tensioners to ensure they operate correctly.  A blown hose or broken belt can mean big repair bills.  Some people carry a spare set of belts for their truck in the event of a problem.  Belt Tensioners and Pulleys for Volvo Trucks.  

Be sure to contact the heavy truck parts professionals at Class8TruckParts.com to help you find the correct parts for your truck.


Posted By Class8TruckParts.com

5 Signs Your Clutch May Be Failing

Jun 7, 2017 7:33:05 AM

While technology has brought vast improvements to truck transmissions and electronics, the job of your clutch remains the same. It’s the “middleman” that links your engine’s flywheel to the transmission gearing.Clutch

Industry data suggests that the average lifespan of a clutch ranges from 350,000 miles, or four years, to 500,000 miles, or five to six years, depending on the truck and its application. Or course, driving habits are a big factor, too. Riding the clutch, upshifting before reaching top gear speed, and engaging the clutch while coasting will all wear a clutch out faster.

A failing clutch will show signs that it’s near the end of its life, so pay attention to the following:

  1. Noise – Most people know to listen for grinding noises, but growling noises are a concern too, as they may indicate a bad release bearing.
  2. Hard to shift – Difficulty getting a truck in gear, even after a recent clutch adjustment, can indicate that a disc spring is broken, among other things.
  3. Unexpected engine revving – If the engine revs in higher gears when you’re on the throttle and under load, your clutch is slipping and may need to be replaced.
  4. Creep – Your truck may creep forward when the clutch pedal is pushed all the way down because the clutch isn’t disengaging.
  5. Drivability – Even after a clutch adjustment, your truck is still difficult to control. It launches with the slightest movement of the clutch pedal or doesn’t engage until the pedal is at the top of its release point.

When it comes time to replace a clutch contact the pros at Class8TruckParts.com.  Don't wait until your clutch has failed completely and you're stuck on the side of the road.  Use these tips to diagnose the problem in advance to prevent downtime.

Posted By Class8TruckParts.com

The time to diagnose a compressor is while it is on the vehicle and a failure can be determined by using a few simple steps. In many instances, compressors are removed due to low refrigerant or a blown fuse.

Step 1— Is compressor rotation smooth?

With vehicle off, turn the compressor shaft with a 14mm socket to check for smooth rotation. Grinding or hanging during shaft rotation is caused by broken components within the compressor.
If the answer is yes, continue with steps 2 – 4.
If the answer is no, replace the compressor.

Step 2 — Is field coil receiving greater than 11.5 volts?

This test should be conducted with the engine running and clutch engaged.
If the answer is yes, continue with steps 3 – 4.
If the answer is no, check and correct vehicle electrical system.

Step 3 — Is field coil resistance between 2.8 and 4.4 ohms?

The coil resistance outside of this range will not engage or will cause fused circuits to open.
If the answer is yes, continue with step 4.
If the answer is no, replace the compressor.

Step 4 — Is the compressor capable of producing 350 psig or more?

Excessive high pressures can be artificially produced by preventing air flow across the condenser, thus minimizing heat removal from the system. This can be best accomplished by disconnecting the fan switch / relay, or simply blocking the condenser with a sheet of cardboard.
If the answer is yes, the compressor is functioning properly.
If the answer is no, use the flow chart below.

AC Compressor Troubleshooting




If you need to replace your AC Compressor, Class8TruckParts.com has a great selection of AC Compressors available to purchase online here

Posted By Class8TruckParts.com

Wheel bearings are some of the smallest components on a heavy-duty truck, but they play a big role. That’s because bearings support the weight of the tractor and trailer, allowing the hub assemblies to turn freely, and the tires and wheels to rotate smoothly.

Wheel BearingsWheel bearings typically last for hundreds of thousands of miles, and the signs they are failing are minimal – at most a grinding or grating noise. But if you don’t address the problem quickly, a failing bearing can drive up fuel costs, decrease stopping distances and cause the truck to feel loose while steering. Even worse, a broken wheel bearing can cause damage throughout the wheel end assembly and lead to a dangerous wheel-off situation.

Fortunately, it’s easy to prolong the life of your wheel bearings and ensure your safety while out on the road. Here are three easy steps you can take today.

  1. Make sure your bearings are properly adjusted – When it comes to wheel bearings, setting the correct amount of end play is critical. In fact, the difference between a too loose or too tight bearing is between 0.001 and 0.005 of an inch – the width of just one or two human hairs. The Technology & Maintenance Council has a great nine-step protocol, Recommended Practice 618, to guide technicians when they adjust bearings. Make sure your shop or local repair facility is following it.
  2. Lubricate – Inadequate or improper lubrication can speed up bearing wear, leading to spalling or fatigue. Always follow your bearing manufacturer’s recommendations when choosing a lubricant and for proper fill quantities.
  3. Avoid contamination – Contamination is the most common cause of bearing failure and can lead to the development of dents or impressions in bearing rollers or raceways. One of the leading entry points for contamination is a failed wheel seal, which can let foreign material in but still hold lubricant in the hub cavity. To avoid contamination, always leave bearings in their original packaging until the time of installation, install them in a clean environment, and replace wheel seals at the first sign of failure.

When it’s time to replace your wheel bearings or seals, turn to Class8TruckParts.com.

*Information courtesy of Road Choice Truck Parts

Posted By Class8TruckParts.com

Simple Reasons and Easy Fixes for Failed Truck Lighting

One of the most common reasons a driver is pulled over and cited is for a faulty lamp; whether it’s completely out, flickering has a broken lens or housing or is mounted improperly. There are many reasons for a lamp to fail. Sometimes the cause for lighting failure can be involved or complex when the problem lies within the electrical system. However, sometimes the cause for lighting failure can be fairly simple, and easy to prevent. The following are just a few situations to watch out for, and suggestions to avoid them.


Not Replacing the Lighting Connections– Corrosion on old lighting pigtail connections can lead to corrosion on the pins of the new lamp. When possible, pigtail connections should be replaced when the lamps are replaced to avoid corrosion build up, which can cause lighting failure.

Positioning Lamps in the Correct Direction

– The bulbs or LEDs within a lamp are positioned in a particular direction, and/or use reflective surfaces within the design of the lamp, to emit light in a specified direction in relation to its function. When a lamp is positioned incorrectly, it is not performing its job properly, offering poor or inadequate lighting. In most situations, proper positioning of a lamp can be determined if text on the lens is right side up. It’s also important to note that there are those lamps that can be mounted in any direction and perform their job function properly.

Over-Torqued Mounting Hardware

– Too much stress placed on the polycarbonate material of a lamp, over time, can lead to cracks in the lens. Mounting hardware should be torqued to no Installation/Replacement/Maintenance Not Replacing the Lighting Connections Positioning Lamps in the Correct Direction Over-Torqued Mounting Hardware more than the manufacturer’s specifications, typically between 8 – 20 In. Lbs. and mounting holes should be periodically checked for damage.

Operating an Incandescent Lamp Above It’s Designed Voltage

– Operating an incandescent lamp on an overvoltage has the potential to create a fire as well as significantly reduce the life of the lamp. By operating an incandescent lamp at just 5% over it’s operating voltage, the lamp life has the possibility to be decreased by half. LED’s are a little more forgiving since they usually operated within a wider voltage range.

Lenses Coming Into Contact with Harsh Chemicals

– Harsh chemicals that come into contact with the lenses on a lamp can weaken the integrity of the lenses over time, leading to damage. Avoid using harsh chemicals when washing a trailer since it’s inevitable that the exterior lighting will most likely come into contact with the cleansing solution.

Parking in Padded Docks with Lamps On

– Heat is created from the light, reflecting off the padding and back onto the lamps, which can cause lenses to melt and even shorten the life of the light bulb or LED. Turning off the trailer lamps when parked in a dock with a padded frame will help avoid this.

Shock and Vibration From Multiple Sources

– Road vibration is a known culprit for premature lighting failure as some bulbs/filaments may break, or become disconnected. However, damage from shock or vibration can also occur during loading an unloading, (including containers onto trailer chassis), when backing in too hard to a loading dock or brunt force contact with stationary objects. So it’s always good to check the exterior lighting after aggressive/heavy loading and unloading, or after a hard jolt with a loading dock. Information courtesy of Phillips Industries
Posted By Class8TruckParts.com

Commercial Truck drivers will log substantially more miles than the average driver does in a year. Today’s modern truck is safer than ever, with improved safety technologies in trucks, allowing shorter stopping distances, stability control equipment, improved ABS. Even with all of these improvements, unfortunately, accidents can still happen, and often it is not the fault of the truck driver. You need to be prepared before you get into an accident, so you know what to do.

The following is 11 steps that will help you get through the immediate aftermath of a crash, and to help you protect your professional reputation and your livelihood as a professional driver.

  1. STOP! When involved in an accident, even if it is minor, do NOT leave the scene until speaking with the other driver, the police, or both. If the incident involves damage to property, not a vehicle, ensure you are able to notify the property owner.
  2. Stay Calm. Try to remain as calm as possible, and do not react in anger.
  3. Is everyone safe? Ensure everyone involved is safe, and contact the authorities immediately to come to the accident. They can dispatch the emergency help needed. The basics in first aid training is, do not move anyone unless there is a danger of fire or future injury if they remain where they are. If anyone in the accident is bleeding, feels lightheaded, or has any physical injury contact emergency medical help.
  4. Safety First. If the accident is minor with no injuries, move the vehicles to the side of the road and out of other traffic. If the vehicle cannot be moved, remain in the vehicle with seat belts fastened until authorities arrive. Walking around in traffic can be dangerous.
  5. Contact the Authorities from the crash site. If you are unable to contact the local authorities, instruct someone to call the local police, or state highway patrol. Do NOT leave the scene until the police officer authorizes you to leave.
  6. Dangerous Cargo? If you are hauling cargo that is dangerous or hazardous, ensure you know the protocols for your cargo to keep everyone on site, and the environment clean.
  7. Prevent another accident. Setup road flares or warning triangles to warn other drivers to prevent another accident. If you have a safety vest or other brightly colored clothing to stand out to other drivers.
  8. Do Not Admit Fault. Do not discuss the details of the accident with anyone by the police. Stay calm, and be polite. Do not admit fault to the other driver or the police. Do not sign any documents or statements, other than what the police require.
  9. Contact Your Employer. Call you dispatcher or fleet manager as per your company’s procedures.
  10. Document the Accident.
  • Photos: When it is safe, take photographs of damage to all of the vehicles, and property involved. Include any photos that also show road conditions, intersections, traffic signs, traffic lights.
  • Report: Write a detailed report of all the details of the accident including time, date, weather and traffic conditions. Keep your driver's logs with this report information.
  • Involved Parties: If possible, ask for the contact details of the other drivers involved in the accident, including their insurance company, and insurance policy numbers, and driver’s license number.
  • Witnesses: Also identify any witnesses or third parties to the accident, and record their contact information for reference.
  • Police Officers: Record their names, badge numbers, and instructions on where and how to obtain the police report, and/or any issuance of citations.
  • Dash Cams: If you have invested in a dash cam, ensure you keep this video footage safe for evidence
  1. Cooperate with authorities. You may be subject to blood and alcohol test that authorities will administer. Remember always stay calm and cooperate with local police and authorities.
Posted By Class8TruckParts.com

SPN, MID, PID, FMI, What do they mean?

Mar 5, 2017 11:05:30 AM

The check engine light illuminates in your dash. Now what do you do?

You see the codes and they are another language. What does the code mean? There are many ECU's on your truck, which one is the problem?

Here is a guide from Volvo to help you interpret those SPN, MID, PID, PSID, SID codes.

Volvo Truck Diagnostic Trouble Code Guide


Volvo Truck ECU Diagnostic Codes Guide

Posted By Class8TruckParts.com
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Wheeling Truck Center
23rd & Market St., PO Box 6808
Wheeling, WV 26003 USA

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