Changing The Clutch On A Semi Truck: A Brief Overview

Automotive Blog

Moving parts eventually wear out on semi-trucks and will have to be replaced. A common problem that develops after tens of thousands of miles on the road is that the clutch will typically wear out. You need to get to a mechanic shop right away so they can replace the old clutch with a new one, and you can get back on the road to make money. This is a job for the experienced mechanic with the right set of tools. Here is a brief overview on how a mechanic will replace the clutch on a semi-truck.

Step 1: Remove Transmission

The mechanic has to remove the transmission to gain access to the clutch assembly on a semi-truck. The truck is raised in the air on a truck lift. A hydraulic jack is placed under the transmission to support the weight of the transmission while the mechanic unbolts it from the clutch assembly. The transmission will stay on the jack when the mechanic moves it to the side so he can work on the clutch.

Step 2: Remove Clutch Assembly

The clutch assembly is removed in the following order:

  1. Clutch brake
  2. Clutch
  3. Non-Captive Disc
  4. Release bearing and Captive Disc
  5. Flywheel

Installing New Transmission

Here is how a mechanic will put the transmission back together.

Main Flywheel: The main flywheel is typically resurfaced and checked for deformities. The flywheel is placed back onto the truck and bolted to the crank flange. Blue thread lock is placed onto the bolts to protect the bolts against rust and corrosion. The thread lock also prevents the truck's vibrations from loosening the bolts.

The bolts are tightened using a torque wrench to manufacturer's specifications.

Two threaded studs are placed at the top of the flywheel into the holes where the clutch will bolted later in the process.

Release Bearing & Captive Disc

The mechanic will place an alignment tool through the center hole in the release bearing and captive disc (the release bearing is built into the captive disc).

A non-captive disc is placed over the alignment tool with the flywheel side of it facing away from the captive disc. The assembly is then slid over the two threaded studs on the main flywheel to hold it in place as the mechanic installs the mounting bolts through the clutch assembly and into the main flywheel - blue thread lock is used on these bolts, too.

The two threaded studs are removed after all the other mounting bolts have been installed. Mounting bolts are then placed where the threaded studs were located. These bolts are also tightened according to manufacturer's recommendations with a torque wrench.

The alignment tool is removed once all the parts have been securely bolted in place.

Install Transmission

New brake pads are placed over the input shaft on the transmission and clipped into place. The transmission is then raised and the input shaft is slid into the clutch assembly. The mechanic then bolts the transmission housing to the clutch housing.

After the mechanic has reinstalled the transmission onto the clutch, he can then proceed to adjust the clutch so everything works well to get your truck back on the road.

To learn more about semi truck repair, contact a company like Arizona Fleet Service


9 November 2015

Driving a New Vehicle Style Was Easier Than I Expected

I drove small compact cars for over a decade. After I got married and had children, I began to realize that we could use more room than we had in my small car. I was considering buying an SUV or a small van, but I hesitated on making the change for quite a while due to thinking that it would be very difficult for me to learn to drive a new automobile style! Finally, I got up the nerve to test drive an SUV at a local dealership, and I was shocked at how easy it was to drive! I felt a little higher in the air, and that was the only difference. I decided to start a blog to share my story with other people afraid to switch vehicle styles and share other auto tips I have learned! I hope I can help you!