Dr Dumb-ass in the house

[mznyc]

First cylinder I go to torque and I stip BOTH rocker arm pivot shaft bolts.Anyone got an extra pair,of bolts and shafts.Shafts look OK but just in case.

Michael

[Guest ratchethack]

Michael my friend! Are you referring to the 10 mm hex-head M5 hardened steel bolts that keep the rocker shaft assemblies?! I'm assuming you mean you stripped the HEADS and not the THREADS?! In order to strip the HEADS, you'd pretty much have had to use the wrong wrench, or one made of cheesy cast pot-metal from Bongo Congo?!?! If you stripped the THREADS, they are also hardened steel! You must've cranked 'em HARD -- CLOCKWISE?!!?

 

We're here to help, but now we're concerned. . . Sometimes when you start out, it's necessary to back up the bus first before you can start it movin' forward again. Let's get that transmission in wotever gear you need, and get after it!!!

 

The better you can communicate, the better the FORMIDABLE resources of this Forum may be brought to bear.

 

Please advise, we'll get thru this with maximum learning, minimum down-time, and minimum trauma!

 

I suggest we proceed from this point forward with more info -- the more info and the higher quality, the better!

 

BTW - I've never priced the rocker shafts, but I suspect new ones could come pretty dear and won't be all that easy to source. The collective World Guzzi Munt Piles are full o'rusty ones, but if you don't need to replace yours, this would be the vastly preferred alternative to a replacement ordeal whereby you also need refurbishment of the parts. We can determine all o' this with inspection and evaluation up front!

 

More info please.

[Greg Field]

Rocker shafts are on the order of $30 each. We have 'em at Moto Intl. if your normal parts vendoer does not.

 

I read it that you wrung the heads off the bolts. Yes? I've seen it done several times. If this is the problem, get a burr on a die grinder and gnaw off the stub of the bolt until you can get the shaft out. Then, if the bolt was not bottomed in the hole when the head broke off, you can usually spin out the stub of the bolt with a lefthand drill bit.

 

Good luck!

[orangeokie]

Rocker shafts are on the order of $30 each. We have 'em at Moto Intl. if your normal parts vendoer does not.

 

I read it that you wrung the heads off the bolts. Yes? I've seen it done several times. If this is the problem, get a burr on a die grinder and gnaw off the stub of the bolt until you can get the shaft out. Then, if the bolt was not bottomed in the hole when the head broke off, you can usually spin out the stub of the bolt with a lefthand drill bit.

 

Good luck!

 

 

Wow! Good info from experience.

[mznyc]

Hi Guys,

I stipped the threads of the 10mm X head M5 hardend steel bolts when re-inserting the rocker arm assembly.Must have started slightly off-thread and turned them clockwise(this is the correct direction to tighten,isn't it?) to tighten,not hard but because I probably didn't thread it in enough ,finger tight(I know better),I stripped the bolt threads.The shafts threads seemed to have survived.But figure a replacement may be in order just so I dont strip the new bolts.I found a replacement from a pile of V11 bolts I bought from Bigrick,same length/diam but a female hex-head,I think they'll be fine for as temp replacement,but want to replace with the correct part.

Another question.In lex's article he states in step #5- part #2,the "The pivot shaft bolts are tightened to 6-8 NM or roughly 53-71 in/ LB".I assume 6-8 is a typo.Should be 60-80 NM?

I'll refer future questions to the original post.

Greg I was hoping to get used but if no one responds by the time you get them I'll order 2.Can you get me the bolts?

Thanks,

Michael

[mznyc]

Well I think I answered my own question.

I checked the workshop manual(should have done that FIRST!) and the pivot shaft bolts are to be torqued to 6-8NM!!

Not 53-71 in/LB as stated in Lex's article.I checked this because I stripped the REPLACEMENT bolts I put in there trying to torgue to 53-71 in/LB s.according to the chart on my torque wrench 6-8 mn would be about 5lbs?

Could you guys through in your

[Guest ratchethack]

YIKES! All begins to come into perspective now.

 

Michael, I don't mean to criticize, such is not my intent. With all due respect, I think there have been lessons learned here that (fortunately enough) haven't come too dear, yet will no doubt stick with you.

 

I don't know of any Pro who would ever use a torque wrench on a M5 bolt, which typically get 6-8 Nm (the Guzzi shop manual spec for the rocker pin bolts, just as you've discovered), which is ~4-5 lbs./ft. M5 bolts everywhere are generally tightened very gingerly and lightly, by "feel". Most torque wrenches (except for highly specialized ones for precision applications), even those calibrated in inch-pounds, don't measure accurately enough that low on the scale to get credible reads on this class of bolt anyway. For a little perspective, consider that spark plugs on the Guzzi are typically torqued to 20-30 Nm, or ~18 lbs./ft.

 

NOTE: I may've made an incorrect assumption previously that the bolts in question are hardened steel. Generally speaking, all critical engine internal bolts are, but in this case they may not be, since they are simply retaining screws, really, and have no need to be hardened -- and this would be a GOOD THING for you here, since this fact may have prevented the tapped holes in the rocker pins from damage. There may be markings or numbers on the heads of the bolts that indicate hardness. If there are, post here and one o' the Pro's can decipher 'em.

[mznyc]

Hi RH,

I'm going to post a question on the original thread as I'm working on it now ,hopefully you can clarify.

Thanks, http://www.v11lemans.com/forums/index.php?showtopic=11552

Michael

[Guest ratchethack]

Michael, Lex has it correctly after all. His conversion is in inch-pounds. You may've read it as foot-pounds. I had to edit my post above, I'd read it too fast and missed this myself.

[macguzzi]

There is NO need to use a torque wrench your just going to muck up the bolts again, those torque settings can be done by a plain spanner, just do them up as tight as you can. Just remember Guzzi makes all of their bolts from cheese.

[motoguzznix]

I stipped the threads of the 10mm X head M5 hardend steel bolts when re-inserting the rocker arm assembly.

Should I own different Guzzis since 24 years than you all?

On my Guzzis the rocke shaft fixing screws are always M6. On every one of my 3 Guzzis from 73 to 2000. The screws are always 8.8 and as such the max torque is 10 - 12 Nm. But I never used a torque wrench to fix these screws as my right arm has the correct torque for M6 stored.

[Guest ratchethack]

Should I own different Guzzis since 24 years than you all?

On my Guzzis the rocke shaft fixing screws are always M6. On every one of my 3 Guzzis from 73 to 2000. The screws are always 8.8 and as such the max torque is 10 - 12 Nm. But I never used a torque wrench to fix these screws as my right arm has the correct torque for M6 stored.

Hm. Lex had written "5mm with a 10mm hex head" in his procedure. This was my recollection also, but the memory ain't wot it used to be. . .

 

Now the Guzzi service manual for a G5 specs the same torque for these rocker pin fastening screws as my service manual for my 2000 Sport -- 6-8 Nm.

 

My manual also specs 6-7 Nm for standard M5 screws and nuts, and 8-12 Nm for M6.

 

But I'm like you. For either one, it's all in the wrist.

 

Thanks for the reference to 8.8 hardness on these bolts, MGNX. That was my recollection also. This is overkill for the application. Like so many other things, the engineers likely spec'd it for something less robust, but volume purchased, higher grade "parts bin" fasteners were likely readily available, so that's likely wot got installed.