Important Point on $3,000 Oil Ring!!

[suecanada]

For all those not receiving the BMW Owners News magazine each month, the latest issue has Matt Parkhouse of "Keep 'em Flying" fame making an EXCELLENT POINT!! We need to share this. Some of this info is old hat but a couple of points aren't:

ONE: Check the distance between the oil filter canister outside end and the sealing surface of the engine block. Should be about 3mm.
- 3mm - use white O-ring, one steel shim under it and no paper gasket on cover.
- less than 3mm - add a paper gasket on cover
- more than 3.2mm - (someone who has the magazine please check this as I can't   figure what Matt means)
- more than 3.5mm - two steel shims required.
- 4.2mm example on a bike Matt was working on took 3 shims.

TWO: NOW, the news to me is what to look for.....the WHITE O-ring should have SQUARED edges from being compressed when taken out for replacement. The squareness shows that it was adequately compressed and doing its job.

THREE: Another gem of NEWS, albeit a LONG SHOT, is that the distance between the end of the oil filter canister and sealing surface of the engine block CAN SUDDENLY CHANGE. Wow, the canister can shift in the engine block.

Can someone read their ON and clarify what Matt meant regarding the 3.2mm depth?  Thanks!

Oh yes, notice that inflation has hit and we're up to a $3,000 O-Ring  now.

[donbmw]

The way I read it is 3mm up to 3.2mm is one shim and above 3.2mm would be 2 or more shims.

Don

[Justin B.]

This is the first time I have heard that the canister can seat itself further all by itself!  I wonder if we should all take a hammer and suitably sized mandrel, made from a soft metal, and assist the canister in "figuring out" out where it's supposed to be?  I always look at the "O" ring as if it comes out too "round" then it indicates not enough "squash" when tightened.

[Joan]

Whoa... migrating oil canister?? Never heard of that before either. Got my ON, I'd better take a look tonight.

[Justin B.]

Sue and Joan, after careful analysis of the article please enlighten those of us who do NOT get the ON...

[not-so-fast-ed]

When I pulled my first oil change I had no idea of the proper sequence of steel shim, "O" ring, gasket.  When I inquired if there was anything I should be aware of when changing the filter, a (to me) seemingly knowledgeable BMW owner replied that I should "just put it back the way it came out".  Bad advice, worth what I paid for it.  Yeah, the PO had the shim on the metal cover & it was leaking oil.  I, of course, put it back the same way, filter, "O" ring, shim, gasket, & it continued to leak.   Back to the dealer for another oil filter kit.  Pulled my filter & found the "O" ring had a slice in it!   MY BAD, I thought.  Once again I put in in wrong, and it leaked.  Pulled it apart to find no visible problem.....  Finally did some additional research at the Snow Bum's site that had me measuring the canister depth and realizing that the shim goes in before the "O" ring.  i.e., filter, shim,"O" ring, gasket.  Using the depth measuring end of my vernier caliper I found that the distance from the engine case surface down to the oil canister was 4.1 mm (4.2 the first time I measured) after holding it firmly against the case in three different areas of the circumference.  According to his info I needed to put TWO shims in, the "O" ring, AND NO GASKET!  Really!  I did and, so far, no leaks!    

[nhmaf]

I've read that article a couple times now, and I was also surprised to hear that in some very rare cases, the cannister can migrate further into the engine block, increasing the clearance and possibly requiring additional shim(s) to compensate.   The bike that he was working on with the problem was a 1992 R100 GSPD with over 100K on the clock, and it needed a new crank, con rod, etc. on the right side.  Matt did say that it was a rare event, but because if it occurred it could cause so much damage to repair due to loss of oil circulation, that he now made it a practice to measure the depth from the block to the edge of the canister on every 1977 or later airhead bike for every oil change.   In most cases an O-ring sealing failure will also result in oil leakage around the cover, but apparently if the sealing isn't quite good enough to maintain the oil pressure, but good enough to keep the oil in the engine, this can be a problem without external symptoms.  The /5 and /6s with the internal cover systems apparently are immune from this migration thing by design.   I've tried to dig up some drawings or photos that could possibly give a clue as to HOW the cannister could migrate inward, but haven't found anything yet.  I believe that it is simply a stamped metal part, so perhaps, through some unknown forces, the metal
at the corners where the lip is stamped gradually weakens and allows the cannister to move inward under the pressure/compression from the cover pushing in ?

He also mentioned that some R65 engines appeared to have LESS than the nominal 3mm depth that was the design standard, for some reason, and that in those instances one needed to use the paper gasket as well to avoid over-compressing the O-ring, though I don't understand that part, and have never used the paper gaskets on either of the (2) airheads I have owned - though both were 80's models.   When I change the filter on my R65, the O ring doesn't appear to be nearly as square/squashed in cross section as the one he shows in the article, but it isn't perfectly round in cross section either.   I haven't measured the depth from the engine case to the cannister lip though and will plan to do so on my next oil change for future reference.

I guess even 'simple' bikes like our airheads have to have their little complexities here and there..

[suecanada]

Thank you nhmaf for the details for Justin and others who don't get the ON. And thank you donbmw for your thoughts that 3.2mm and over gets 2 shims. The squashness factor is a great thought.

[Justin B.]

I  wonder, then, as a matter of prevention if somebody should give the canister a "smack" and re-measure to see if there was any movement.  Could maybe prevent something from sneaking up on ya down the road?

[nhmaf]

I don't know if I'd dare smack it - depending on what you hit it with you might tend to cause more damage.  I am going to get another set of calipers to keep out in the garage though, and measure this thing during the spring oil change.

If someone here wants it, I have the ability to scan the article into a PDF (Adobe) file and email it to you - just PM my with your email address info.

[Justin B.]

I was thinking about turning a round gizmo out of aluminum, something like a seal installer, that would fit perfectly inside and over the lip on the canister.  I find it impossible to describe an object without a pencil and paper...