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3/4 turn method for oil filters

ac_oldman

Active Member
What's the 3/4 turn method for oil filter torque?

I assume it is:
- use a marker to label 90deg / 180 deg / 270 deg / 360 locations (and maybe in between)
- after screwing on the oil filter, from the moment the gasket touches the body, using the markings as reference, ensure it's been turned an additional 270 degrees?
- safety wire.
 
Spin on the filter 'til the gasket touches then turn 3/4 turn more. Really doesn't matter if it is 269 or 271 degrees, don't get anal.
 
Oil Filter

You can?t go wrong with the official guidance, 18 to 20 ft lbs is the torque for the Champion brand. They also specify Dow Corning DC-4 as a lubricant on the rubber gasket before install. The 3/4 turn method with some engine oil on the gasket works well enough if you know what tight enough, but not too tight feels like.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
The 3/4 is bush style... better follow the manufacturer?s instructions, usually a specified torque.
Also beware that some, Tempest as an example, are installed dry no oil.
 
If you don't have a fancy torque wrench, "Bush Style" works pretty good, and has done so for a few decades. In fact, some filters have the "3/4 turn" instructions included. Could that be construed as "Manufacturer's Data?"

Some things require more precision than others.

Just my Dos Centavos.............
 
If you don't have a fancy torque wrench, "Bush Style" works pretty good, and has done so for a few decades. In fact, some filters have the "3/4 turn" instructions included. Could that be construed as "Manufacturer's Data?"

Some things require more precision than others.

Just my Dos Centavos.............

I would hope everyone that does ANY maintenance on their RV has access to a torque wrench. Does not need to be fancy, but it is a must for aviation.
 
Torque wrench

Couldn't agree more that a torque wrench, or two or three torque wrenches, are needed for construction and maintenance of aircraft.

However, most standard torque wrenches and their required sockets or crowfoot extensions don't fit easily on the oil filters installed on most RV aircraft. Hence the existence of "fancy" purpose-built oil filter torque wrenches.

I borrowed a friend's oil filter torque wrench, and at the same time, I marked the filter for a 3/4 turn.

Result was withing a few degrees of the 270 degrees required.

Again, sometimes precision is required. Sometimes it's not. I would submit that oil filter torque is not a close-tolerance issue.

YMMV, as always.
 
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Just did the oil filter change gig yesterday. Champion. Hitting resistance and then going 3/4 turn is not enough torque IMHO. I torqued to that standard, then torqued further to 18 ft/lbs and was really surprised to see how much more was required to get to spec.
 
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Exactly!!

How do you put a torque wrench on a WIX oil filter?

The filters I have used for 15+ years do not require a torque setting - only +3/4 turn after the o ring touches the pad. I put silicon goo on the o ring just in case. Never had a car/mower/tractor/truck/farm gas/diesel tank or airplane engine filter come loose since I have done oil changes (60+ years) - why would an aircraft use be any different? My 2 cents, anyway.

I will admit to having some troublems when getting the filters to come loose - that 3/4 turn really does the trick, but sometimes you will need a helpful tool to get ?em off. Filter wrenches might be required for removal - 3/4 turn is all that is needed for the ON process.
 
...Never had a car/mower/tractor/truck/farm gas/diesel tank or airplane engine filter come loose since I have done oil changes (60+ years) - why would an aircraft use be any different? ...

That's what I told the IA who did my condition inspection this year. Took me 15 minutes to add a hose clamp to the filter and safety wire it so he would be happy and sign it off. :rolleyes:
 
Never had a car/mower/tractor/truck/farm gas/diesel tank or airplane engine filter come loose since I have done oil changes (60+ years) - why would an aircraft use be any different?
FWIW six months ago my wife took her new car (2019 Toyota Rav4) to the dealer for it's 1st oil change. 200miles later the filter came loose and dumped all the oil. She was on the interstate when it happened so by the time she shut the engine off the damage was done. Now our new car has an even newer engine in it.

Morale of the story; "Never say never," especially in an airplane.

:cool:
 
FWIW six months ago my wife took her new car (2019 Toyota Rav4) to the dealer for it's 1st oil change. 200miles later the filter came loose and dumped all the oil. She was on the interstate when it happened so by the time she shut the engine off the damage was done. Now our new car has an even newer engine in it.

Morale of the story; "Never say never," especially in an airplane.

:cool:
Perhaps the difference is that the F1Boss does the oil change himself, hence making sure things are done correctly. It is amazing how many times I have heard of stories like your wife's experience. A good friend of mine's daughter had a similar experience with the oil change at one of the national chain oil change shops. They also got a newer engine.
 
FWIW six months ago my wife took her new car (2019 Toyota Rav4) to the dealer for it's 1st oil change. 200miles later the filter came loose and dumped all the oil. She was on the interstate when it happened so by the time she shut the engine off the damage was done. Now our new car has an even newer engine in it.
Morale of the story; "Never say never," especially in an airplane.
:cool:

Morale #2: Never take your airplane to an auto dealership for an oil change!
 
FWIW six months ago my wife took her new car (2019 Toyota Rav4) to the dealer for it's 1st oil change. 200miles later the filter came loose and dumped all the oil. She was on the interstate when it happened so by the time she shut the engine off the damage was done. Now our new car has an even newer engine in it.

Morale of the story; "Never say never," especially in an airplane.

:cool:

You should have bought a Ford ! :D
 
Interestingly Rotax uses the 3/4 turn method and there is no safety wire. I make a point to check the mark before each flight. ;)
 
You should have bought a Ford ! :D
I once did that and the auto shop store became my second home for the amount of time I spent there.
Since, I have owned three Toyotas and all +/-200K miles and never visited the repair shop, only oil/brake/tire and windshield wipers.
 
I once did that and the auto shop store became my second home for the amount of time I spent there.
Since, I have owned three Toyotas and all +/-200K miles and never visited the repair shop, only oil/brake/tire and windshield wipers.

It was a joke for my old boss. I currently own a F150 and a ‘66 Ford and also a Toyota Tundra.
 
Or to any of those quick change places ! Took my Tundra and a month later had to rebuild the transmission.

The only time I used one of the "quick change" places was when I had a Ford Escort.
The filter was exactly above the exhaust. You could not possibly change it without burning yourself. My procedure was to have the oil changed, let the car sit overnight in the garage and then, when it had cooled down, loosen and reseat the filter.
 
APPROVED!!

That's what I told the IA who did my condition inspection this year. Took me 15 minutes to add a hose clamp to the filter and safety wire it so he would be happy and sign it off. :rolleyes:

Yep - if that is all it takes to get his signature. You can take it off now..:eek: BTW that will allow any others who think the wire is magical to use the less expensive filters too! As another time saving device, can re-use both the wire AND clamp!;)
 
My RV taxi

After the dealer nearly stripped out the drain plug on my taxi I use to pick up RV parts, i dont let monkeys work on my cars anymore.
 
I've posted this before, but what the heck:

It's interesting to note that Robinson Helicopter does not require the safety wiring of the Lycoming engine oil filter per their Service Letter shown below:

https://robinsonheli.com/wp-content/uploads/2015/12/r44_sl45.pdf
SUBJECT: Deleted Safety Wire​
"BACKGROUND: Safety wire and safety wire provisions have been deleted from various installations and parts. Deleting safety wire reduces maintenance cost and decreases the potential for safety wire-related FOD. This letter provides guidance for installing parts with or without safety wire provisions."

...

"? Lycoming engines: Oil filters and D723-1 adapter assemblies with or without safety wire provisions do not require safety wire. Installation instructions are on the oil filter."​
If a helicopter manufacturer doesn't think it's necessary ...

(For transparency, my oil filter is safety wired.)

Also helicopter engines operate at full rpm constantly and are composed of a whole mess of parts all trying to vibrate themselves apart.
 
Yep - if that is all it takes to get his signature. You can take it off now..:eek: BTW that will allow any others who think the wire is magical to use the less expensive filters too! As another time saving device, can re-use both the wire AND clamp!;)

I left it on, had more important things to do and it doesn?t bother me one way or another.
 
Buy buying a quality clamp? Is that a trick question?


No.

I've never had a filter loosen or a clamp.

But if you keep adding 'safety' where does it stop...............

Clamp too loose, doesn't do anything. Too tight, you might put a hole in the filter.
 
No.

I've never had a filter loosen or a clamp.

But if you keep adding 'safety' where does it stop...............

Clamp too loose, doesn't do anything. Too tight, you might put a hole in the filter.

I haven't either. If you read my comments I never use them and I use WIX filters but had to or my CI wouldn't be signed. He didn't like the WIX filter either but I wasn't going to remove a new filter so he accepted it. I could have taken the clamp off right after he left but that would mean wasting more time on a useless situation. Next oil filter change it stays off.
 
Actually, the 3/4 turn method is far more accurate than a torque setting (not that it is super critical in this application). 3/4 turn will always compress the gasket the pre-determined amount. The filters have 16 threads per inch, so 16 turns will produce 1" of travel. Therefore one turn will produce 1/16" of travel. 3/4 turn will compress the gasket 0.046875". You cant say the same for a torque setting. - Prove it to yourself by doing both. Mark the filter and then set it with a torque wrench. Measure the rotation you achieved. Also use a inside caliper to measure the gap between the filter face and the filter housing face. Do this over a few oil changes.

For high precision "Torque" settings the angular method is always the preferred method. A torque wrench is used to ensure all parts are pulled-in together and then a angular rotation is set using a torque angle gauge: https://www.amazon.com/OTC-4554-Dri...angular+rotation+gauge&qid=1586780774&sr=8-12
 
All cannister oil filters are tested(developed) to a standard test procedure. Today it may be some ISO test, but the 3/4 turn was based on the SAE hydraulic pulse test to ensure it would not fail internally, or come loose. Included is a 1/2 turn and even a 1/4 turn test to be sure it is not on the edge of acceptability. The pulses and pressures are much higher and any engine produces, diesel or gasoline.

There has to be a historical reason for safety wire, but not sure why torque is involved, it was not part of the past test procedure.

If a Toyota filter "came loose" it was never tight.
 
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For high precision "Torque" settings the angular method is always the preferred method. A torque wrench is used to ensure all parts are pulled-in together and then a angular rotation is set using a torque angle gauge: https://www.amazon.com/OTC-4554-Dri...angular+rotation+gauge&qid=1586780774&sr=8-12

Last year I overhauled one of the heads on my 911 which uses one-time-use stretch bolts that are torqued to an initial NM torque then torqued to an angle. I tried one of these tools and they are a bit of a pain so I got a highfalutin Snap On digital torque wrench that does angular torque. Just for kicks I marked the bolts with a protractor and sharpie and found that method to be nearly as good as the angle reading on my torque wrench.
 
All cannister oil filters are tested(developed) to a standard test procedure. Today it may be some ISO test, but the 3/4 turn was based on the SAE hydraulic pulse test to ensure it would not fail internally, or come loose. Included is a 1/2 turn and even a 1/4 turn test to be sure it is not on the edge of acceptability. The pulses and pressures are much higher and any engine produces, diesel or gasoline.

There has to be a historical reason for safety wire, but not sure why torque is involved, it was not part of the past test procedure.

If a Toyota filter "came loose" it was never tight.

Rav oil filters are cartridge filters. They do not seal the same as spin on filters.

The Rav filter failed because it was not tight.
 
However, most standard torque wrenches and their required sockets or crowfoot extensions don't fit easily on the oil filters installed on most RV aircraft.
This. The oil filter *just* fits between the engine and the firewall on my RV-6 when it's first placed into position (before spinning on). I can't only just get a closed-end wrench onto it when it hits the rubber. No way I could get a torque wrench in there.

And since all the filters i've seen say 3/4 turn after bottoming on the rubber, there's no real need for a torque wrench. I've never seen a safety wire on an oil filter that was under any tension when it came time to remove it, either, and yet I still safety it because "it's always been done that way."

Unfortunately the closest safety wire point on my twice-overhauled-and-due-for-a-third Lycoming finally wore to the point where it broke off the last time I did an oil change, so I had to safety the filter to another nearby hard point.
 
You can?t go wrong with the official guidance, 18 to 20 ft lbs is the torque for the Champion brand.
I strongly disagree. A few oil changes ago, I torqued a Tempest EZ-Spin filter per their instructions and, at the next oil change, it was frozen solid. The can wouldn't budge no matter what I tried. Ultimately the can was completely destroyed by using 1. An Anti-Splat wrench; 2. A standard oil filter wrench; 3. A screwdriver driven through the can; and 4. An oil filter wrench with spikes on the tips. Even after I chiseled the can off from the base, a set of 24" Channel-Loks wouldn't budge the base. Don't be this guy:

Al01Rm.jpg


I actually had to use a BIG hammer and chisel to pound on the circumference of the base to break it lose. I will NEVER torque to manufacturer's specs agaion. Now I use the 3/4 turn method with no problems. A couple flights ago I used the hand tight plus 1/2 turn method and I'm still alive to tell about it.
 
I actually had to use a BIG hammer and chisel to pound on the circumference of the base to break it lose. I will NEVER torque to manufacturer's specs agaion. Now I use the 3/4 turn method with no problems. A couple flights ago I used the hand tight plus 1/2 turn method and I'm still alive to tell about it.

Just changed my oil today and had a similar but not quite so bad experience. Had to put a 3 foot cheater bar on my ratchet to budge the Tempest oil filter that was installed to specs- no lube and 16 ft lbs of torque. Fortunately my oil filter is located up high where use of the extension is possible

Erich
 
3/4 turn always works. I have that ‘special’ oil filter wrench. It torques the can tighter than 3/4, every time. I don’t use it. 3/4 turn doesn’t over torque the filter, and doesn’t leak. That’s the measure - doesn’t leak. Second measure - you can get it off during the next oil filter change. This is a relatively liberal spec, dealing with a compressible gasket subject to relatively low pressure - usually less than 100psi. With a fairly coarse thread, safety wire will hold the torque pretty close, even if you don’t get the safety wire installed really tightly.
 
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