When you consider how often you have to use your clutch in your semi, it’s not surprising that eventually, it will wear out. Depending on the type of driving you do (mountain vs. flat, rush hour vs. open road, etc.), you may discover your semi-clutch needs to be replaced sooner rather than later.
The actual cost of the clutch itself is not high, but the labor involved in replacing the clutch adds a significant amount to the overall price. Moreover, the mechanic who replaces your clutch has an impact on the cost as well.
The total semi-truck clutch replacement cost is between $1,000 and $5,000, which includes the cost of the new part and between eight and 10 hours of labor. There may also be some variance in cost based on the type of clutch that needs to be replaced.
If you purchase the clutch assembly and replace it yourself, you’ll spend between $500 and $1,800, so you can save quite a bit of money if you know how to replace your own clutch.
However, the replacement process is complex and if not installed properly, it could lead to bigger issues down the road. Since the clutch is responsible for allowing you to change gears when you’re driving, you can’t get away with not replacing it if it’s going bad.
There may be some instances when a clutch can be repaired instead of replaced, but with the low cost of the actual clutch, replacement is almost always a better option.
Factors in the Cost of a Semi Clutch
There are several factors that go into determining how much your semi-clutch replacement will cost. The first is the part itself, which can vary in price based on the manufacturer.
Different clutch models cost different prices, so the brand of truck you own determines the clutch you need, which then determines the cost of the part.
OEM Vs. Aftermarket Parts
Second, the vendor you purchase your clutch from will affect the price. If you buy the clutch online, you may pay less than if you purchase it from a dealership.
Check around to see if there are different price points for the clutch you need so that you pay the lowest price possible. Typically, OEM parts are going to be the best for your truck because they are specifically designed for the model, but they’re also going to be more expensive.
You can get these parts from the dealer, and if you get your clutch replaced at the dealership, they’ll automatically use OEM parts.
Type of Transmission
The type of transmission that’s in your truck is another determining factor in price. Automatic transmission clutches for semis are significantly more expensive than manual transmission clutches.
Automatic transmission clutches run upwards of $1,500, while manual transmission clutches hover between $600 and $1,000. However, you can find even more expensive manual transmission clutches depending on the brand you choose.
For example, a heavy-duty 15.5-inch ECA clutch from New Eaton Fuller is over $2,500.
The third factor that can affect the semi-truck replacement cost is who does the actual replacement. Mechanics set their own rates, which means you’ll be quoted different replacement costs for your clutch.
A mechanic at a dealership will charge a different rate than an independent mechanic, but you should also take care to ensure the mechanic you choose has the right experience working on your truck. Otherwise, a cheap clutch replacement could turn into a more expensive major repair.
Signs of a Failing Semi Clutch
If your clutch fails entirely, it could cause an extremely dangerous situation while on the road. For this reason, you need to learn to recognize the signs that your semi-clutch is failing. This way, you can get it replaced before it goes out entirely.
The most obvious sign of a failing semi-clutch is slipping. When your clutch is new, the friction plate, flywheel, and pressure plate are all tightly compressed together so that when the clutch is engaged, your gears shift immediately.
When a friction plate is worn, though, there isn’t enough friction between the flywheel and pressure plate to instantly engage the clutch or to keep it engaged while you’re in gear.
If you feel the clutch slip out of gear without input from you or you notice it’s disengaging more quickly than usual, your clutch is probably wearing out and will need to be replaced soon.
Slipping gears can be a major issue if you’re driving down a steep grade or if you’re trying to accelerate to get past other vehicles. Another sign that your clutch is wearing out is a sticky clutch.
You may be having trouble disengaging the clutch when you press on the pedal. This is typically an indication that the rod, cable, or hydraulic is failing. A sticky clutch should be investigated right away and either repaired or replaced.
Unusual noises coming from the transmission or a burnt smell when you shift gears are other signs of a possible clutch issue. Any time you hear or smell something odd, it’s better to have your truck fully inspected to ensure it is in safe operating order.
While you can drive on a worn-out semi-clutch, the performance of your truck is going to be severely compromised. You’ll have trouble changing gears, staying in gear, slowing, and accelerating. It can create a dangerous event if you’re unable to change gears or slow down when you need to.
Other than driving and performance issues, continuing to use a worn clutch can result in damage to other parts, including the flywheel. When a clutch slips, it generates a significant amount of friction on the flywheel and will eventually cause it to crack. A flywheel for a semi is much more expensive than a clutch assembly, which you’ll also have to replace.
The labor costs for installing a new flywheel are similar to the labor costs associated with replacing a semi-clutch, but since both parts will require repair or replacement if you let the flywheel gets damaged, you’ll end up paying more than necessary. Paying attention to your clutch and getting it replaced as soon as it becomes worn will save you money in both the short and long term.
How to Extend the Life of a Semi Clutch
The best way to extend the life of your semi-clutch is to make sure you’re driving your vehicle properly. First, don’t “ride the clutch,” which is the term for keeping the clutch partially engaged when it doesn’t need to be.
This creates more friction on the internal clutch components and causes them to burn up more quickly. Keep your foot away from the clutch when you’re not actually shifting gears.
When you’re stopped at stop lights or at street crossings waiting for traffic to clear, put your truck in neutral rather than sitting with first gear engaged. There’s no need to put pressure on your clutch when you’re sitting still.
Finally, change gears quickly and decisively. The longer you keep your clutch depressed, the more pressure you’re putting on its internal components. Usually, this is only a problem for inexperienced truck drivers, but if you’re taking longer than a couple of seconds to change gears, you’re adding unnecessary wear on your clutch.
Be decisive and make the shift as quickly as you can.
DIY Semi Truck Clutch Replacement
Some semi-truck drivers can perform the semi-clutch replacement on their own so that the only cost they have is the price of the new clutch assembly. However, clutch replacement on 18-wheelers is more complex than on typical cars and trucks and usually requires special tools that most drivers probably won’t have.
To replace the clutch you’ll have to remove the transmission to gain access to the clutch assembly, which includes the clutch brake, clutch, non-captive disc, release bearing, captive disc, and flywheel. The transmission will be set aside while you work on the clutch but will have to be reinstalled once you’ve replaced the clutch.
Also involved with replacing the clutch is aligning the release bearing, captive disc, and flywheel. This process requires a special alignment tool that you may not have access to.
Without this tool, you won’t be able to install the clutch properly, leading to additional problems later on. If you do have the tool, aligning the clutch should not be difficult, but will be time-consuming. Once you’ve replaced the clutch and reinstalled the transmission, you can proceed to adjust the clutch so that it shifts quickly and smoothly.
You’ll need a friend to help you complete this task since someone has to be inside the cab pushing the clutch pedal all the way to the floor so you can use a socket wrench to turn the adjuster bolt.
DIY Cost Vs. Dealer-Installed Cost
If you’re able to replace your own semi-clutch, you’ll save about half what you would pay to have a dealer or mechanic install one. If the average semi-truck clutch replacement cost is $2,500, you can expect that the clutch assembly cost you about $1,250 and the installation cost you about $1,250.
This is just an estimate, though. In some cases, the clutch assembly may be more than half the cost, while the mechanic’s charges are lower. In other instances, you might pay more for the actual installation while the clutch price is reduced.
Overall, however, you can expect to double the price of an aftermarket clutch to have it professionally installed.
Choosing the Right Clutch
If you take your semi to a mechanic or dealer to replace the clutch, they’ll take care of getting the right part for your truck. However, if you buy the clutch yourself, whether you intend to install it yourself or not, you need to make sure you purchase the right one.
Otherwise, you could end up paying more for a second replacement sooner than necessary.
To determine the correct clutch for your semi, you’ll need to know:
- Whether your truck has a hydraulic linkage
- Your truck’s engine torque rating
- The size of clutch that you’re replacing (in inches or millimeters)
- Your truck’s shaft diameter and number of splines
- The number of damper springs on each clutch disk
- Whether you want a pre-damper to eliminate idle noise
Once you know the answers to those questions, you can look up the clutch you need to purchase on a semi-truck parts vendor website or in a parts book. Then, shop around until you find one at a reasonable price.
The clutch is a critical component of an 18-wheeler, and without it, you won’t get very far. To save yourself money and hassle in the long run, get your semi-clutch replaced at the first sign of failure.