Repair – Clutch Job
This is an overview of what happens during a clutch job at Art’s Automotive.
This is a picture of the transmission in the car before the work was started. The yellow arrow points to the top of the transmission. The transmission must come out to replace the clutch. As you can see, there is a lot of stuff blocking access to the transmission.
This next picture is the transmission viewed from under the car after the splash shield was removed. The yellow arrow is pointing to the lower control mount on the sub-frame. The transmission will not come out past this mount, so the sub-frame will need to be removed.
Below is the sub-frame removed from the car. It spans the front of the car, going all the way from the left wheel to the right wheel.
Theses are the parts that are replaced when we do a clutch job.
This is the clutch disc. It rides on the transmission input shaft. The clutch disc is squeezed between the pressure plate and flywheel to transfer power to the transmission.
This is the pressure plate. It bolts to the flywheel, which bolts to the engine. It provides the pressure to squeeze the clutch disc and a friction surface.
This is the clutch release bearing. Since the pressure plate is always spinning and the clutch release fork is stationary, the bearing is necessary absorb the spinning motion.
Below is the flywheel grinder. The flywheel is quite expensive, so it is usually not replaced unless it’s absolutely necessary. The flywheel friction surface is every bit as important as the pressure plate surface, so it does not make sense to reinstall a worn part without repairing the surface. Most shops either do nothing to the flywheel or send it to a machine shop to be resurfaced. Art wisely realized that even though a flywheel grinder is an expensive piece of shop equipment, it will pay for itself fairly quickly. The cone is made from an abrasive material and spins very quickly. The flywheel is bolted to the table, which turns slowly, just like a turn table on a record player.
Here’s the flywheel grinder in action.
This is the flywheel after grinding. The friction surface has been ground perfectly flat and the “step” (the area the pressure plate bolts to has also been ground to maintain the original flywheel dimensions.
First the flywheel is installed on the car, then the clutch disc, then the pressure plate. Since it’s hard to take pictures of this with these parts on the car, I took the pictures on the bench.
After the flywheel is bolted to the crankshaft, the disc comes next.
Next the pressure plate is installed and bolted to the flywheel.
The release bearing is next in line. The release bearing is actually installed on the transmission, but I thought this picture helped to illustrate where it connects with the pressure plate.
This is a picture of the inside of the transmission bell housing The yellow arrow is pointing to a pivot point for the release bearing fork. The release bearing fork is like a teeter totter. On one side the lever is a hydraulic slave cylinder or clutch cable that will move when you step on the clutch cable. On the other side is the release bearing that presses against the pressure plate release levers to disengage the clutch. The red arrow is pointing to the release bearing sleeve. This is where the release bearing rides. The blue arrow is pointing to the input shaft splines. All of these points must be lubricated with high quality grease to prevent noise or stiffness in the clutch.
This is the inside of the transmission bell housing after the release bearing and fork have been installed.
Once the clutch is replaced the transmission is put back into the car. When I asked Erick why he didn’t use one of the $1000 transmission jacks we own, he said he could have the transmission installed in the time it would take to pull the jack out and mount the transmission to it, and he was right. It took 20 seconds from the bench to the car.