Crankshaft Pulley Holding Tools
Homemade Tool for Older Civics
When changing the timing belt on Honda automobiles, often the most difficult step is removing the crankshaft pulley bolt. It is difficult because the unusually fine threads of the pulley bolt make it more prone to galling and seizing, particularly given the extreme conditions under which the bolt must function. The pulley bolt is called a "special bolt" in official Honda documents because the threads are non-standard. They have a smaller pitch than is customary for even fine-thread metric bolts. The torque necessary to loosen the bolt can rise to over 300 ft-lbs. The archive reports difficulty breaking the bolt free with compressed air-driven wrenches rated over 500 ft-lbs.
One option for freeing the pulley bolt is to use a special tool for fixing the crankshaft pulley in place and then applying the necessary torque to the bolt. The tool to use will depend on the particular year and model of Honda. The evidence is that there are three categories of pulley designs, and so three different tools. The pulleys within a category do not all look exactly the same; rather, within a category, all the pulleys do have common characteristics. The three categories follow.
1. Hex Design
See pictures below. From top left proceeding clockwise: (a) Pulley and bolt; (b) pulley holder tool and 19 (or 17) mm socket & ratchet on bolt; (c) tool. This is used on a few early 1990s Honda models and newer Hondas. If you have a Prelude or a manual transmission Acura, you may need the 45 mm size of the tool. I think all other Honda and Acura models with the hex style pulley use the 50 mm size of the tool. To purchase a tool for this pulley, try Amazon and Ebay, searching for {honda pulley tool}. Try also a google search, which should turn up sites like To fabricate your own tool, see Hex Homemade Pulley Holder Tool.


2. Lip Design
See pictures of the pulley and a tool below. This is what a 1991 Civic LX and some other circa 1990 models use. The "lip" is for the power steering belt. Compare it to the non-lip design below. This pulley bolt requires a 17 mm socket.

3. No Hex, No Lip Design
See pictures below. This is used on older Honda models c. 1980s. Note how the commercial tool on the right below has a prong that inserts into one of the holes near the pulley's circumference.

To purchase a tool for (2) or (3), try Amazon and Ebay. One can also purchase this tool at online stores like Skywaytools Pulley Holder tool. Two variations on this tool design are available, as shown in the pictures under (2) and (3) above. Both work the same way, inserting into the holes around the periphery of the pulley. To fabricate your own tool for (2) or (3), see No Hex Homemade Pulley Holder Tool.