Hub Unit Case Study: Shop Owner’s Perspective

Hub Unit Case Study: Shop Owner’s Perspective


I read a lot of “case studies” written by technicians online and in magazines. Rarely do I see case studies written by a shop owner who works at the front counter. Here is a story of how high-quality parts can make the customer, technician and me happy.

7:00 am

It was a Monday morning. A customer dropped off one of his work trucks over the weekend. The 2019 Ford F-150 was sitting in the parking lot. The owner called on Friday afternoon to ask if we could look at a truck because the driver reported a ratcheting noise and grinding from the right front. He also said he needed it back on Tuesday for a big job. After a quick write-up, I fished the keys out of the drop box and assigned them to a technician.

8:12 am

According to the technician, the test drive revealed something interesting. The ratcheting noise only occurred in 2WD and changed when 4WD was engaged. However, a grinding noise remained no matter what mode was engaged and depended on the vehicle’s speed. Back at the shop, the visual inspection revealed nothing unusual. From previous experience, we knew that the ratcheting noise could be a symptom of an issue with the Ford Integrated Wheel End or IWE.

The system applies vacuum to the actuator when in 2WD. It shuts off the vacuum when in 4WD to engage the hub and axle. This is the reverse of how most locking hubs operate. If there were a vacuum issue, it typically would cause noise from both wheels. But, the noise was coming from only the right front.

The Ford IWE 4WD system does something no other truck can perform. The system not only disengages the hub, but also the axle from the hub. This improved the fuel mileage when the truck is in 2WD. To do this, the IWE actuator moves a collar over a sprocket mounted to the hub unit.

8:30 am

We decided to make sure there was vacuum at the wheel with the engine running. The vacuum gauge revealed there was vacuum being delivered to the IWE actuator. The unit would not hold a vacuum when a vacuum was applied to the actuator using a hand-held pump. We now confirm the IWE actuator at the wheel is malfunctioning. With the vehicle running on a lift, it was easy to tell that the passenger side bearing was making noise compared to the driver’s side. The technician wrote his diagnosis and recommended replacing the actuator and hub unit.

9:15 am

Now, it is time to write the estimate and find the parts. Looking at my suppliers, I can see many options for the wheel hub. Some shops will sort the results by price or delivery time. But I know these are secondary considerations for my customer, who wants the truck to operate with the least possible downtime.

The unit we selected was BCA’s  WE61945 from our local WD. It was not the least expensive nor the one with the fastest delivery, but I know the BCA unit has the highest quality that meets or exceeds the original unit. The IWE actuator was also sourced from the same WD.

9:15 am

Now, it is time to write the estimate and find the parts. Looking at my suppliers, I can see many options for the wheel hub. Some shops will sort the results by price or delivery time. But I know these are secondary considerations for my customer, who wants the truck to operate with the least possible downtime. The unit we selected was BCA’s WE61945 from our local WD. It was not the least expensive nor the one with the fastest delivery, but I know the BCA unit has the highest quality that meets or exceeds the original unit. The IWE actuator was also sourced from the same WD.

9:30 am

We contacted the customer with the estimate for replacing the hub unit and IWE actuator. He texted us back with the two-word response, “Do it.”

12:30 pm

When the parts arrived, we examined the hub unit from BCA. We have ordered other brands of hub units and have had problems. We first noticed that the wheel speed sensor wiring harness was the same length as the original and had the correct connector. We have found that these harnesses can be too long or short on economy units. Many companies will try to go to a length that might fit multiple years or applications.

The other thing we noticed was the sprocket that engages with the axle. The BCA unit uses the same manufacturing processes as the original unit, which secures the cog to the hub unit. The process is called orbital forming, which attaches the cog to the unit. It rolls the lip of the inner race with extreme force to secure the cog to the hub unit. It also sets the pre-load of the tapered roller bearings.

Some manufacturers use alternative processes to secure the cog and set the preload. But, some of these methods do not create a strong bond.

The other issue we have found with IWE units can be the roller bearings inside the axle bore. These allow the axle and hub to move independently. While they don’t support the vehicle’s weight, they keep the axle aligned so 4WD engages effortlessly. Low-quality hub units might develop play that can damage the IWE actuator. Which is what I suspected happened to this truck.

1:04 pm

We started the job once we received the parts, and the technician was free. I knew I had the truck for only a few more hours, so I was dismayed when I saw the technician on his phone in the middle of the job. When I stopped by the bay, the technician wanted to show me something on their phone. This never ends well. I was stunned to see this

All he had to do was scan a QR code included inside the box. I guess this means one less trip to the information station to look up the torque specifications. With the IWE, the torque specifications are critical. This is especially true for the bolt that secures the axle to the flange. This small bolt has a torque specification of only (30 ft/lbs).

2:30 pm

At our shop, the front counter staff must perform a test drive as part of the quality control process. I took the truck for the test drive. The ratcheting and grinding were gone, and the truck shifted into 4WD effortlessly.

4:05 pm

The customer came to pick up the truck and was satisfied. He asked if we could handle a wheel bearing and ball joints on his F-250 next.

This Article is Sponsored By: BCA Bearings by NTN





Automotive

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