If you are boating in deep fresh water and suddenly feel vibrations due to the crankshaft pulley wobbling, you should worry about your boat and engine.
Don’t worry because the topic under discussion today is why the crankshaft pulley wobbles and does it need to be fixed.
By the way, there can be multiple factors involved in causing the crankshaft to wobble, which I’ll discuss in detail later on. However, I am sure of one, and that is you need to get it fixed as soon as you realize the wobbling.
It’s essential to learn about the importance of the crankshaft pulley and its functionality before doing the wobbling root cause analysis.
Table of Contents
What is a Crankshaft Pulley?
A crankshaft pulley is responsible for driving the alternator and multiple engine components. Also known as the harmonic balancer, and is located at the front end of the crankshaft. Moreover, the wheel you see mounted on the crankshaft is actually the pulley.
The crankshaft generates rotational energy to turn the crank pulley, which in turn runs other parts of the vehicle. It uses ribbing to keep the belt from slipping during the revolutions.
The main purpose of the crankshaft pulley is to reduce the vibrations originating from the engine.
It basically turns the belts that operate the engine and other parts. Furthermore, it holds separate belts or maybe a serpentine belt for the alternator and air conditioner. Either a single strap or an entire system of belts depends upon the year and boat type.
For instance, before the mid-1980s, most of the boats included V-belts to drive the engine’s parts.
You must be wondering about the belt-driven features and components. These include coolant circulation, providing charging for the electrical system, hydraulic pressure. Other optional accessories include an air conditioning compressor and heavy hydraulic pumps.
Causes of Crankshaft Pulley Wobbling
The bad news is that there is a possibility that the pulley may become faulty with time and may require a replacement.
You can quickly look for the symptoms of a faulty crankshaft pulley. One of them is undoubtedly wobbling. However, a defective crankshaft pulley creates a loud knocking noise or leads to the non-working of other engine accessories.
Some other symptoms to check are:
- Abnormal engine vibrations
- Alternator failure
- Power steering pump failure
- Transmission damage
- Irregular idle engine speed
Rubber Belt Condition
Furthermore, you can check the condition of the rubber belt. If it’s worn out or damaged, it may lead to timing problems and may wobble.
Another reason may be the loosening of the crankshaft bolt that secures the pulley to the engineer. If it gets loose, you don’t need to replace the belt. Instead, you can tighten the bolt without investing in buying a new belt.
Crank Bolts Not Tight Enough
Moreover, if the crank bolts aren’t tight enough, the bolt starts to lessen and subsequently causes the crankshaft pulley to wobble. Not only that, it chews up the crank keyway and woodruff key.
Failure in Any of the Two-Part Assembly
The crankshaft pulley consists of two parts with a flexible layer between them. The central part is bolted to the crank, while the outer assembly consists of heavy metal. Moreover, the rotational mass smoothes out the engine firing pulses.
However, if any of the two parts fail, they should be replaced immediately.
No Wobbling Effect at High RPM
Sometimes, the crankshaft pulley wobbles, but you may not be able to feel any squeaking at a higher RPM. My sincere advice to you is not to ignore such a situation.
It’s because the pulley has a center breaking, which becomes unnoticeable at higher RPM. Subsequently, ignoring it may lead to some severe damage to the engine itself.
Poorly Manufactured Pulley
It’s another common reason which causes the crankshaft to wobble.
If the input rate of rotation is greater than the rotation’s output rate, it’s known as underdrive. A poorly designed pulley can face serious side effects due to underdrive in the power steering, air conditioning units, or alternator.
Sometimes, the belt isn’t of the right length or the number of grooves. For instance, you may be using a five groove belt to a six-groove pulley or vice versa.
Consequently, it may lead to the wobbling of the crankshaft pulley.
If you encounter an accident that directly contacts and damages the crankshaft pulley may lead to wobbling.
Distorted Fan-Belt Pulleys
If the fan-belt pulleys that bolt to the harmonic balancer are dismounted, bent, or distorted, it may cause the crankshaft pulley to wobble.
You can remove these pulleys using the standard tools. Then, check them for flatness or rust. Sometimes, some dirt may get trapped under the pulley.
Furthermore, the crankshaft pulley tends to wobble if it isn’t appropriately torqued.
Over Tighten Drive Belt
Over Tightening the drive belt can cause a severe imbalance and destroy the crankshaft pulley.
A crankshaft pulley comprises many parts, including inner steel, rubber isolator, and outer steel. Aging is a natural process that can cause contamination or defects in any of the layers.
The only feasible solution is to replace the pulley.
Effects of Crankshaft Pulley Wobbling
The crankshaft is made of heavy-duty cast iron or solid steel. That’s why it’s strong enough to withstand the stress of placing the crankshaft pulley. Furthermore, the tension increases from driving all the components off the single pulley.
If the crankshaft pulley starts to wobble, it will eventually throw off the belt. Not only that, but other components that depend on the pulley’s drive power will ultimately fail.
Fixing Crankshaft Pulley Wobbling
Lucky for you, the factory-stock fasteners and other thread-locking liquids serve as a fail-proof solution to tighten the crankshaft pulley. Furthermore, the pulley remains in place for a more extended period.
Check the bolts
A round-shaped pulley is usually attached to the crankshaft by a large bolt and a thick washer at the center. Else, four small bolts around the inside edge of the pulley hold the shaft. Both these scenarios depend upon the vehicle model.
All you need to do is to remove all the belts which are driven by the crankshaft pulley. Later on, you can see if there are any loose bolts. It’s better to tighten all the bolts to be sure.
Furthermore, remove the large bolt using a strap wrench to check the damages on the crankshaft itself. In case the end of the crankshaft is damaged, you are only left with one option – replace the crankshaft.
Many crankshaft pulleys come with an internal dampener, which ultimately reduces the vibrations running along with the pulley belts. In this way, you can save the connected system from any kind of potential harm.
By the way, you can individually replace a broken or worn-out crankshaft pulley belt. On the other hand, if a dampener becomes faulty, you’ll have to replace the entire crankshaft pulley.
You can remove the belt to ensure there isn’t any dirt, grease, sand, or belt material jammed in any of the grooves. Additionally, check the smooth-sided pulley for damage, dent, or dirt.
How to Replace a Crankshaft Pulley?
You can easily obtain an engine pulley remover on rent from an auto parts shop. All you need to do is to unscrew the central bolt and remove the defective pulley from the engine.
Moreover, you can follow these steps to fix/replace the pulley:
- Disconnect the battery
- Remove the drive belt
- Remove the old pulley
- Install the new pulley
- Finally, torque the pulley
You can easily get a GEARWRENCH Pulley Puller and Installer Set, including one puller, one jackscrew, one bearing, one thrust washer, puller ponds, and four screws. The GEARWRENCH is a reliable company renowned for its reliable automobile products and kits.
However, if you don’t want to buy a professional kit, you can simply opt for an Opall Crank Pulley Tool Kit. It comes with a crank pulley tool, one reinforcement ring, and two sets of removable pins.
The best thing is this kit is quite affordable and comes with a one-year warranty. Moreover, it comes with an integrated low profile handle allowing you to remove the crank pulley conveniently.
This screen wrench holder comes with a new V2 design with an upgraded small pin.
Else, you can hire a novice mechanic to do the job. Moreover, you don’t need to spend extra bucks in hiring a seasoned mechanic.
Crankshaft pulley wobbling may be a first sign or the final sign of extreme wear and tear.
It’s essential to perform a routine check-up of the crankshaft pulley to see any wear or damage signs. As we all know, “Prevention is better than cure.”
Ignoring the crankshaft pulley will lead to some severe damage to the engine, crankshaft, or belts.
Therefore, what’s a better option, in your opinion? Replacing the crankshaft pulley or the engine itself?
I know you are smart people and can do the math yourself.
Take care of your crankshaft pulley, and don’t let it wobble!