This is a home-crafted oil filter wrench for tight spaces on modern automobile engines. It is made from an old piece of 1/2 inch black iron pipe and a pipe end cap. Also used is some discarded bicycle chain. The wrench is operated by a 3/8 inch drive socket ratchet.

The chain tightens its grip on the oil filter as the pipe twists when pressure is applied to the ratchet handle.

Step 1: Commonly Available Filter Wrenches

These common wrenches do not always fit the space available on an automobile. The end cap style (center) sometimes should fit a particular filter, but does not. Sometimes no end cap wrench is available for a particular filter. The wrench described in the Instructable can be made to fit whatever filter your car uses.

Step 2: Drill the End Cap for the Ratchet

Drill a 3/8 inch hole in the center of the end cap for the ratchet.

Step 3: Square the Hole

Work carefully with a small file to make the round hole square so the ratchet will fit into it the way the ratchet fits into a wrench socket.

Step 4: The Ratchet in the Hole

Here you see the ratchet's square end partially inserted into the hole in the end cap.

Step 5: Mark the Pipe for Drilling Holes

I stuck a piece of masking tape onto the pipe for marking where to drill holes for the chain. I considered using three pieces of chain and made the markings, but later decided on only two. Also, use a pipe wrench and a vise to screw the end cap onto the pipe as tightly as possible. That should be sufficient to keep the end cap from unscrewing when pressure is applied by the ratchet.

Step 6: Drill Holes in the Pipe

The size of the holes you drill will depend on the size of the chain you use. My chain was 9-speed chain for a 27 speed bicycle. I needed holes just a little larger than 3/8 inch. Drill the holes through both sides of the pipe, upper and lower.

Step 7: Fit the Chain to Your Filter

Slip the end of the chain through one set of holes and wrap it around an extra copy of your oil filter. Note which pin in the chain to use when opening the chain.

Step 8: Using the Chain Tool

If you have not used a chain tool before, push the pin far enough that you can wiggle the chain and the one piece separates from the other, but not so far that the pin comes out completely. In the photo you can see the pin extending toward the upper part of the photo. Its end is almost flush with the outer edge of the chain tool.

Step 9:

Make a second piece of chain the same length as the first. Place one end of each piece of chain through a set of holes in the pipe and connect the two ends of each piece of chain. Your wrench should look like this when finished.

Step 10: On the Car

Here you see the wrench on the oil filter on my car. Space is not as limited on this car as on some. Still, this could be a very handy wrench for removing or installing an oil filter on many cars where space is very limited.