F&M Oil filter adapter AND THREAD DRIFT-LOL

[Bill Hart]

I recently had my O-300A overhauled and with the overhaul I had an F&M oil filter adapter added. Once I got the engine installed and running the oil filter adapter was leaking. I was afraid I’d over torque the adapter so I called F&M and was told the following.

1st My adapter has 2 crush washers. It is supposed to only have 1 crush washer and 1 fiber washer. The guy at F&M wasn’t sure how I ended up with the 2 crush washers.

2nd and this is the reason I am posting this. Apparently on some O-300 where the adapter fits into the rear case the fit isn’t that good so F&M will have to turn down the outside of the adapter 10,000 of an inch.

3rd some times the threads on the rear case need to have a thread chaser run down inside to clean up carbon build up.

The guy at F&M did an outstanding job at customer support in my opinion. He is sending me the new gaskets and they will loan out the thread chaser for the cost of shipping. Hope this helps someone out there.

[Bruce Fenstermacher]

1st My adapter has 2 crush washers. It is supposed to only have 1 crush washer and 1 fiber washer. The guy at F&M wasn’t sure how I ended up with the 2 crush washers.

Bill I believe in the beginning of the F&M history they did come with 2 crush gaskets but had leaks and the fiber gasket was developed.

2nd and this is the reason I am posting this. Apparently on some O-300 where the adapter fits into the rear case the fit isn’t that good so F&M will have to turn down the outside of the adapter 10,000 of an inch.

Never heard this before

3rd some times the threads on the rear case need to have a thread chaser run down inside to clean up carbon build up.

Yes this is not new and while new customers may not know about chasing threads we've discussed it here several times over the years

The guy at F&M did an outstanding job at customer support in my opinion. He is sending me the new gaskets and they will loan out the thread chaser for the cost of shipping. Hope this helps someone out there.

Yes the newest owner (he's owned the company for several years now) is very customer friendly and as a good track record of support for his product. Glad to hear that is still the case.

[GAHorn]

This product, in order to quickly develop market recognition, was first marketed through El Reno Aviation and was popularly referred to as the El Reno filter adaptor. (El Reno still handles the product as a trade line, and may still have early versions of it in stock. For that reason it's best to specify the latest product, or to obtain it directly from the mfr.)
The early version used two commonly available copper crush washers and had a flat face where it mates to the accessory case. This version was known sometimes to leak. (The earliest installation instructions also failed to specify the proper torque and low torque was a contributing factor to leaks.)
FM Enterprises made minor changes to include a chamfer at the mating face (improved axial location), a composition gasket at the mating-face surface (improved sealing and vibration issues), provided installation torque specification, and advised to clean older engine cases of carbon in the threaded area (provide more accurate torque), solving the leak complaints.
They do provide excellent customer support. It's the filter adaptor I have on my airplane, and I've had no trouble with it at all. My only criticism is that it is not fully sealed internally, which may allow some by-pass to occur. I'd prefer an O-ring in a groove on the mid-portion of the smaller galley, but I'm not overly concerned. This engine pumps about 4 gallons of oil per minute and that volume sees to it that the oil is very well filtered with the FM product. I prefer the FM Enterprises installation because it does not require hoses or modification to, or mounting on, the firewall.)




http://www.fm-enterprises.com/product.html

[cessna170bdriver]

I'm currently running the F&M filter adapter on my O-300A. I have also used the Cessna filter adapter in the past. (Sorry, but I don't have the part number handy.)

Afer running both types, quite frankly I think I like the Cessna filter adapter better. (YMMV of course!) It uses a jam nut on the adapter against the sump which makes it easier to hold the adapter in the correct orientation while torquing. The large hex jam nut on the Cessna adapter is easier to torque than the smaller square aluminum boss on the F&M. In my experience, the jam nut on the Cessna adapter is also much less likely to allow the adapter to loosen at the sump when removing the filter, a likely source of leaks. I end up having to re-torque the F&M about every other time I change the oil, a real PITA. Also, the Cessna filter has only one seal, an o-ring under the jam nut, as opposed to the crush washer and fiber seal on the F&M. One positive thing about the F&M (IMHO) is that you get a new bypass valve every time you change the filter.

I bought the Cessna adapter originally because that was the only approved filter that I knew of at the time (about 1990). As I recall, that adapter was about the same number of $ back then that the F&M is now. I haven't priced a Cessna adapter lately, but if you were now choosing between the two, I would imagine the price difference may make the F&M worth dealing with. In the meantime, I still have a servicable Cessna adapter...

Miles

Miles

[GAHorn]

The problem with the "Cessna" adaptor is that it allows vibration to loosen/damage the threads in the accy. case, leading to failure of the adaptor (and possible loss of the engine/airplane) in flight. The "Cessna" system led to AD notes in other TCM engines due to this problem.

[cessna170bdriver]

I never had my Cessna adapter come loose in over 1000 hours of operation. Never even cracked the torque seal.

I haven't had any problems in flight in over 100 hours of ops on the F&M either, but it has come loose in the case twice while changing the filter. Any suggestions?

Miles

[GAHorn]

Is it properly torqued? (I'll bet, being yours, that it is, but you might just want to be certain.)

Do you use Dow-Corning DC-4 (silicone grease) to lubricate the filter gasket? Every time? (Or do you use a little motor oil? .... which causes it to stick after heat is applied?)
Do you torque the filter correctly (according to it's placarded torque?) (Or do you just give it a firm twist, and then another just to be "safe"?)

How do you remove the old filter? Do you use an automotive type filter wrench (or socket/spanner/wrench) in such a manner that it places torque along the lateral axis? (left/right in such a manner as to unscrew the adaptor) Try using the tool such that the first motion of the tool to un-spin the filter is in a fore/aft direction.

[cessna170bdriver]

Is it properly torqued? (I'll bet, being yours, that it is, but you might just want to be certain.)

I mark the edge of the filter when the gasket contacts, then hand-tighten another 3/4 turn; same way I did it with the Cessna adapter. No leaks and no problem with removal.

Do you use Dow-Corning DC-4 (silicone grease) to lubricate the filter gasket? Every time? (Or do you use a little motor oil? .... which causes it to stick after heat is applied?)

I've been using DC4 on oil filter gaskets since the second one I ever installed...

Do you torque the filter correctly (according to it's placarded torque?) (Or do you just give it a firm twist, and then another just to be "safe"?)

Same answer as the first question.

How do you remove the old filter? Do you use an automotive type filter wrench (or socket/spanner/wrench) in such a manner that it places torque along the lateral axis? (left/right in such a manner as to unscrew the adaptor) Try using the tool such that the first motion of the tool to un-spin the filter is in a fore/aft direction.

I normally use an automotive filter wrench for removal, unless the shop I'm in happens to have a socket or box-end to fit the bottom of the filter... again, the same method I used with the Cessna adapter. My point is that in perhaps 40 oil filter changes using the Cessna adapter, I never once inadvertently loosened the adapter in the case. In four oil changes with the F&M, I've inadvertently loosened it twice and had to re-torque.

I'm not sure if the jam nut on the Cessna adapter does a better job of holding the adapter in place, or if its the fact that the F&M filter is further below the centerline of the hole in the case, and angled further back, causing more torque on the adapter while removing the filter...

Miles

[GAHorn]

Is it properly torqued? (I'll bet, being yours, that it is, but you might just want to be certain.)

I mark the edge of the filter when the gasket contacts, then hand-tighten another 3/4 turn; same way I did it with the Cessna adapter. No leaks and no problem with removal....

Miles

I didn't mean the filter (although that certainly is important.) I meant is the adaptor properly torqued?

Mine has never loosened in the seven years since I installed it.

[Bruce Fenstermacher]

Miles, George uses a special secret Texan technique he can't disclose, that is why his filter adapter never loosens. Or perhaps being on the left or right coast has an effect.

My F&M filter adapter will loosen if I'm not careful to torque the filter in a way that is in a different rotational plane then the filter adapter. And I use DC-4 and a torque wrench when installing the filters and a wrench on the end of the filter to remove it.

[cessna170bdriver]

I didn't mean the filter (although that certainly is important.) I meant is the adaptor properly torqued?

Mine has never loosened in the seven years since I installed it.

OOPS! I should have known you're smarter than to ask the same question twice in the same post... I torqued the adapter to the spec in the instructions, using a crow's foot and accounted for the (slightly) increased arm. I've never had it leak or loosen on it's own. It's tough to keep the crow's foot on the square lug, pull the torque wrench, AND keep the adapter from spinning in place. Definitely a two-person job. It might be easier with some sort of special tool that would self-align on the square lug. Can you post a pic of the tool you use? (Maybe while you're at it, post of a pic of if/how you safety the adapter to the engine.)

As for removing the filter, no matter where you pull from, SOME loosening torque will be imparted to the adapter because the axis of the filter is not perpendicular to the axis of the adapter. By eyeball, the angle looks like about 30 degrees, which would transfer about half the torque of loosening the filter to loosening the adapter.


The model C6SC would be better in that respect, but I'm pretty sure there would be issues with engine mount interference:


Miles

[4583C]

Miles
I fretted for some time about what tool to use to tighten that 1" square adapter. I sorted through "the tools that never get used" and found an adapter for using 1" drives on 3/4 inch sockets. I liked the idea of having four surfaces on the adapter rather than two. And my engine hasn't leaked yet.

[GAHorn]

Well, I don't have a handy pic to post, sorry.
But I do pay attention to avoid any rotational forces placed upon the adaptor. It's important to only "spin" the filter...not to place stress upon the adaptor.

If one pulls on a filter-wrench to impart an un-screwing spin on the filter in such a way that a starboard-to-port (or vice-versa) torque is imparted to the adaptor...then I can see where it might move the adaptor.

I avoid any sideways push/pull on the unit by insuring my efforts to un-screw the filter are effected only on the filter....not the adaptor.

(I also used a Pratt & Whitney square socket to install my adaptor rather than a crow's foot.)

Never torque the filter more than 18ft/lbs. Most folks overtighten oil filters.

[Bill Hart]

I torqued my fliter to 16 ft lbs and when I tried to take it off the whole shebang came lose, and yes I use DC-4. I am still waiting on the new washers from F&M so I can't work on it till I get home from Dallas anyway.

[cessna170bdriver]

(I also used a Pratt & Whitney square socket to install my adaptor rather than a crow's foot.)

Where might one acquire these tools (without a mortgage)? I did yahoo and google searches on "Pratt & Whitney square socket " and only came up with a 2003 post by you to this forum. (Maybe the machine shop here could use a bit of practice...)

Miles
I fretted for some time about what tool to use to tighten that 1" square adapter. I sorted through "the tools that never get used" and found an adapter for using 1" drives on 3/4 inch sockets. I liked the idea of having four surfaces on the adapter rather than two. And my engine hasn't leaked yet.

Something like this? http://www.sears.com/shc/s/p_10153_1260 ... ve+adapter You still have to adapt to the 3/4" male lug. An 8- or 12-point socket?

BTW, Have you poured any oil into your engine yet? The old adage is if a (insert engine make/model of choice) isn't leaking oil, then there isn't any in it.

Miles