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The duck, fiber spacer, etc.

Posted: Wed Jun 03, 2009 10:14 am
by T.Hanson
Pull apart one, the spacer wasn't fiber it was steel. Figure a PO made a switch. Now I pull apart another, to find a two part plastic combo. Spacer within a spacer, little black one that slides inside a larger plastic ring.

One, I don't understand why the spacer under one particular bolt head. Looking at the back of the head, I don't see any obvious need for such a gizmo, for oil flow or what, in lieu of a shorter bolt.

Steel, plastic, fiber, two piece, one, *#@!

Re: The duck, fiber spacer, etc.

Posted: Wed Jun 03, 2009 12:40 pm
by Mike W.
T.Hanson wrote: One, I don't understand why the spacer under one particular bolt head. Looking at the back of the head, I don't see any obvious need for such a gizmo, for oil flow or what, in lieu of a shorter bolt.

Steel, plastic, fiber, two piece, one, *#@!
It's a seal, not a spacer. I don't know why they did it the way they did, but it's needed because the gasket doesn't really seal that bolt hole, and the area sees considerable oil due to the rear cam bearing discharging it's oil there to eventually drain. It's an odd setup, it does work, but it seems like the hard way to do it.

Posted: Wed Jun 03, 2009 1:50 pm
by T.Hanson
I'm applying sealant to the duck side of the gasket, torquing all bolts to 60 inch pounds. Closest 8mm, aluminum into aluminum bolt value I see is the top timing cover to bottom, 6 to 8 ft pounds. Don't trust my big foot pound, clicker torque wrench after busting the head off a sump bolt waiting for a click.

The two piece plastic ( mickey mouse ) spacer looks new and wasn't leaking. I've got a new one (2) ordered, having no idea ( without any notes in any book ) if that bolt needs extra sealant, special torque.

I do know fooling around back there with the engine installed is a test of patience.

Thank you,

Posted: Wed Jun 03, 2009 3:02 pm
by under the radar
if its not too much trouble, could you guys explain what you're talking about. what bolts need seals on them? what is a "duck"? thank you. sorry for being a noob. :oops:

Posted: Wed Jun 03, 2009 7:20 pm
by T.Hanson
On the end of the head nearest the firewall is a plate, with a gasket and six bolts holding them to the head. Camshaft rear cover, Haynes manual, page 27. See parts view on realoem.com.

Somebody smoking their socks decided the shape of the cover / plate looked like a duck, and it stuck. Looking at the plate from the back, the plate has a bolt that is furthest right, closest to the exhaust manifold side in a v point on the plate. That bolt gets a wave washer first, then a fatter fiber spacer washer (seal) that sits against the plate.

If your duck ain't leakin', you'll see it's a tight fit to fool around with the bolts between the head and firewall, and say thank you, goodbye Mr. Duck.

Posted: Thu Jun 04, 2009 1:52 am
by alotawatts
under the radar wrote: what is a "duck"?
....and maybe more the outline of the gasket then the plate. Look @ part # 5 here:

http://bmwfans.info/parts/catalog/E12/S ... nder_head/

Posted: Thu Jun 04, 2009 2:30 am
by Mike W.
And I'll add, it's amazing how much oil can leak out of the rear cam cover, AKA duck gasket if it is leaking. :shock: I had a leaker once and it didn't just weep out a bit, it covered everything on a daily basis. And as has been mentioned, not fun to change.

Posted: Thu Jun 04, 2009 6:49 am
by T.Hanson
Thus, do you agree with my install method ? I.e., gasket goo one side, torque to 6 foot pounds, including spacer bolt.

Posted: Thu Jun 04, 2009 12:48 pm
by Mike W.
T.Hanson wrote:Thus, do you agree with my install method ? I.e., gasket goo one side, torque to 6 foot pounds, including spacer bolt.
One side, hell, I put Permatex #3 on both sides! And it wasn't one of mine that leaked on me, LOL. Plus the seal on the bolt of course. 6 pounds sounds about right, but I do it wrist tight. :wink:

Posted: Thu Jun 04, 2009 12:49 pm
by Mike W.
Duplicate

Posted: Thu Jun 04, 2009 7:20 pm
by under the radar
thanks for the explanation!