luckett

Do all oil filters that you would find on the shelf at the local auto parts store have the same threading?

KuHL 951

Not at all or are you joking?

luckett

Not joking, never even thought about it before. I've never even tried to put a filter where it didn't belong either. A recent thread about someone putting on an incorrect filter raised the question.

So what threadings are used for filters?

KuHL 951

Most production vehicles have either a 3/4-16 thread or 20mm. The easiest way to tell if you are not sure is to use a good 3/4" open end wrench and see if it will go around the threads. If it does it's the most common 3/4-16; if not it's 20mm. Many Euro and JDM cars are 20mm at home but use the 3/4-16 in North America. There are a few oddball threads out there but who cares about a 1975 Saab V-4 anyway.

jacklet

there are only a few different thread diameters and pitches seals are in different areas but if it spins on and the seal is in the right place it will work-this doesn't even touch on the subject of anti-drainback valves etc etc etc.

alordofchaos

That was a question I was kinda thinking about a couple weeks ago... I was looking at some oil filter relocation kits.

Course, I didn't know the size and threading off-hand and have been too lazy to check (just got back from a week trip and been kinda swamped)