4 Ways To Remove A Stuck Crankshaft Pulley Bolt

If you're planning to pull and rebuild your engine, think about cracking the crankshaft pulley bolt loose before unhooking the motor mounts. The crankshaft pulley bolt is notorious for holding fast despite using powerful tools and long leverage bars to remove it. Furthermore, the pulley tends to spin and spin as you try to bear down on the bolt head. Once you have this bolt freed, you can move onto the rest of the removal, rebuild and installation process unhindered. Here are four ways to remove this stubborn bolt.

Soak in Lubricant

Although the bolt sits on the side of the engine, you can use putty to create a sticky dish for your lubricant of choice. Mold the putty into a half bowl shape and adhere just under the crankshaft pulley bolt.

The sides of the dish should extend up past the bolt to submerge it completely in lubricant. You may need to clean away some of the grease and grime first to help the putty stick in place.

Fill up the dish with lubricant spray and let it sit overnight. Check the bolt the next morning to see if it will budge. If not, reattach and refill the putty bowl and let the lubricant penetrate the bound materials.

Rent A Powerful Impact

If you only have a 3/8" impact on hand, you may need to rent a 1/2" or even 3/4" monster impact from a rental facility to break free that stubborn bolt. Make sure to obtain a plug-in model, as you'll probably spend more than ten minutes reefing on the bolt.

Make sure the tool has a sturdy connection to the bolt to avoid rounding out the sides. If you do round out the bolt, you'll need to use an extraction tool and a lot of patience to remove it.

Spray the bolt down with lubricant before beginning to use the impact. Let the impact hammer away at the bolt for a few minutes before spraying it back down with lubricant. Repeat this process until it busts loose.

Try a Long Breaker Bar

You can obtain a three-foot or longer breaker bar to attempt to use leverage to bust the bolt loose. It's not appropriate to fashion your own breaker bar, or cheater bar as it's often called, by linking wrenches together for this project. Instead, you need to obtain a solid bar that will not break under force.

Longer bars multiply your effort several times over.  Do not just press down on the end of the bar; instead use repeated small pushes in an attempt to jar the bolt free. Be sure to use plenty of lubricant on the bolt as you work. Be patient, using a breaker bar to free the bolt will take a lot of time and effort.

Bump the Starter

If you're brave, you can use the force of the starter to loosen the crankshaft pulley bolt. Make sure to check the direction your pulley turns when the vehicle starts up. For example, on Hondas the crankshaft spins counterclockwise, which is the opposite direction of most other compact car engines.

Place your socket on the crankshaft pulley bolt and wedge the end of your ratchet or breaker bar onto the ground. Make sure when the pulley starts to turn, the breaker bar is positioned to push the bolt counterclockwise to loosen it. Otherwise, you'll end up tightening the bolt even more, or possibly break its head clear off. Quickly bump the starter to slightly spin the crankshaft pulley and, hopefully, loosen the bolt. Only try this maneuver a few times and check the position of the breaker bar after each attempt.

Take It To A Shop

If you cannot get the crankshaft pulley bolt loose, remove your engine and take it to the shop. For a more specialized approach, take it to an import car repair shop. You should not take your entire vehicle into the shop or you'll have to tow it back home once techs loosen the pulley bolt. Instead, transport your engine there and have the technicians pop the bolt loose using their extremely high-powered impact tools. You may need to leave the engine at the shop overnight if the bolt needs to soak in professional grade lubricant before removal.