Wildguzzi.com
General Category => General Discussion => Topic started by: Dirk_S on August 02, 2019, 05:45:42 PM
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A couple questions I came up with after replacing my cylinder head due to a broken stud:
- I know the head stud nuts require a criss-cross tightening pattern. The manual states as such, and echoed by all you lovely folks smarter than I. But do nuts need to be loosened and re-tightened after a few miles like they once were prescribed? I didn’t find verbiage in the manual that advised this, but saw it recommended for older models that used possibly a different type of gasket? New gasket style = no need?
- I also didn’t find a torque spec for exhaust manifold studs. Is there a listed spec, or do I simply hand tighten with a little extra turn of the wrench?
Thanks!
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Exhaust nut torque - 10Nm or 7.37 ft/lbs. Found in Workshop Manual - Tightening Torques section.
I believe, with the new style gaskets, that once the head is torqued on, it's not specifically needed again. Though I'm ready to be corrected on this.
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The "new style" gaskets are used on the NEW STYLE HEMI HEADS.
The V7II required the head retorque from the factory. So if the replacement gaskets are the same as the OEM ones, c you'll want to retorque them.
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I would add that the exhaust column nuts should be tightened evenly, so that the what the parts book calls a ring nut, part GU32121010, sits squarely on the gasket. I don't know whether the service manual states this, but it's good practice.
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Appreciate the responses. The gaskets are OEM. I’ll make sure to re-torque after a few (hundred?) miles. And solid point about keeping the manifolds (“ring nut”) square for even pressure.
* Note for anyone newer to Guzzi maintenance like me - the 2 exhaust spacers between the “ring nut” (manifold) and the exhaust outlet should have their lips facing outward in order to prop against the inner bevel of the ring nut on one side and against the exhaust gasket on the other for a properly tight fit. Sometimes we (read: I) learn things by doing them backwards ;) Worth sharing because I had only seen one clarifying comment through internet search, and the manual photo was inconclusive.
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I would add that the exhaust column nuts should be tightened evenly, so that the what the parts book calls a ring nut, part GU32121010, sits squarely on the gasket. I don't know whether the service manual states this, but it's good practice.
When you torque them to 10 Nm they are evenly tightened. Definitely test the column nuts regularly for the correct torque. After 6 years I lost one of them, the others were loose. However the engine was out of the frame for the first time before. Dealer´s work...
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When you torque them to 10 Nm they are evenly tightened....
In my experience, that's not always true. Both nuts can be at proper torque but the ring nut may still be askew.
Another example of this uneven cinching problem is the front wheel axle-binding screws at the end of the left fork. Even the manual specifically states that they should be both loosened and tightened evenly.
I totally agree with you that the exhaust column nuts need frequent checking; I re-torque mine at every oil change, and they usually need it.
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Well, I have to admit I in fact use the same method here that Guzzi prescribes to torque the two stud screws that clamp the front axle in the fork (also 10 Nm): torque the first, torque the second, then torque the first again. This way I have good aligned rings.