How to Fix a Cross Threaded Oil Filter

by Michael Rippetoe

Changing the oil in a car or truck is the most important maintenance to do. If not changed regularly or properly, the engine can seize and end up needing to be replaced. When changing the oil, one of the common problems is a leaking filter after the change is done. There can be three causes for the filter to leak: it is loose, the old filter gasket is still on the mounting surface or it is cross threaded. The latter of these is one that commonly occurs when the filter is difficult to reach; when this happens, it is simple to fix.

Step 1

Remove the cross threaded oil filter. This may require the use of a filter wrench or, if a more difficult case, a pry bar. If the filter is cross threaded, there is a strong possibility that the mounting stud will come out with it.

Step 2

Clean the entire filter mounting area. This will help to ensure that dirt does not get into the new threads on the new mounting stud.

Step 3

Remove the old mounting stud if it did not come out with the filter. Some studs require a large Allen type wrench to remove; check with the vehicle manufacturer or your local parts store.

Step 4

Clean the engine side of the threads for the new stud. The engine side threads will be a different pitch and size from the oil filter threads. To make sure of the oil filter threads, test-fit the new filter onto the stud.

Step 5

Place two drops of red thread locker on the engine side threads of the new stud. This will help to ensure the new stud does not inadvertently come loose.

Step 6

Install the new stud. Be sure not to cross thread the stud onto the engine or mounting block. Tighten the stud no more than two full turns past hand tight. Over-tightening the stud can break it.