valve cover stud bolt repair

[kenlodge]

i was at a stop light, almost to work, when i looked down to the the right valve cover nut and stud bolt sticking out from the right valve cover about 1.5".    

i knew this day was coming--it's been leaking/dripping a bit more lately out the valve head cover, & it's never really felt right when i've tightened up on the nut (having just replaced the head cover gasket again).  ...likely been over-tightened by the previous owner(s).

the 10mm nuts are holding well on the back--& i've read in the forum that some can get away w/no 13mm nut at all (currently in my lunch bag).

so...what to do?
is this a JB Weld kind of fix or what?  pull the cylinder head & head to the nearest drill-press?  

it could be worse, but just thinking about this is making me thirsty.

[Bob_Roller]

Needs to have a threaded insert installed to get the job done once and for all .

[tvrla]

The best solution is a threaded insert. I've also heard there's a longer stud with more threads into the head. If you ever noticed, your original didn't reach the full length of the hole and the new one does. Get two and replace the one on the other side at the same time.

[kenlodge]

thanks fellas -

yeah, the stud only has about 5/8" of thread holding onto the head.

[bruce_launceston]

You can install a helicoil type thread insert without removing the head.
I did mine a couple of years ago and reinstalled the standard stud.

[montmil]

You can install a helicoil type thread insert without removing the head.
I did mine a couple of years ago and reinstalled the standard stud.

[size=16]+[/size] [smiley=thumbup.gif]  In fact, I've had the stud exposed in the small air gap located in the head below the sprak plug. The large, chrome acorn nut had rough threads and kept turning the stud until it popped out. A bit of LockTite on the stud's Helicoil insert end is a good idea.

Monte

[tvrla]

Guys have also run a longer stud through the head with enough out the back side to fasten a nut to lock it.

[kenlodge]

picked up a couple studs from the local BMW shop - same size as the old one, just a little shinier.

[tvrla]

I read a tech Article by Oak and he says there are longer studs, and gave a part number for them. Your parts guy evidently doesn't know about them. I'll see if I can dig up the article and the part number he gave.

[kenlodge]

ok thanks.
i picked up a thread repair kit from Grainger.  new stud installed using Loctite red on the right side cylinder head.  nut holds much better for sure.
the L side is next.  for some reason it seems to leak out the L side when i'm riding, but more out the R when it's on the stand--side or center stand.

but even after the helicoil insert, the oil leak is still there--esp on the left side: my left boot is becoming ULTRA waterproof.
any thoughts on what's the next step to kill the oil drip?  

[Bob_Roller]

Maybe a set of rubber valve cover gaskets, they are thicker than the stock paper  gasket ans a lot more compliant .

[kenlodge]

thanks, Bob - i think i'll order up a pair of these & see how it goes:
Real Gaskets http://realgaskets.com/files/motorcycle.htm#bmw

[nhmaf]

Sometimes the head surface is warped (usually on the R100) or it is possible for the valve cover surface to not be flat and result in oil drips.   I have a 78 R100/7 that has had a long and eventful life, and the only way I could get the valve covers to stop leaking short of adding alot sealant to the cover gaskets was to go with the thicker, squishy gaskets from RealGasket.    you can get them in black now - used to be only available in bright orange, which was somewhat of a fashion statement, I guess...

[montmil]

Remove the two threaded studs from the rocker cover. You'll need to locate a dead flat surface to confirm the "flatness" of the cover's sealing surface. Any gap -head to surface- of over 0.003 inches, you'll need to use some wet-dry sandpaper to level the gasket surface.

To check the head's gasket surface for flatness will require removing the valve rocker arm, at a minimum. A quality steel rule, used on edge, may be helpful to check out the head.

Be very critical of surface cleanliness prior to refitting new gaskets.

[kenlodge]

will do, Monte & nhmaf.  
that was my next question--if the surfaces could be a little warped...
will definitely check that out.

...& there is a good bit of filth there on the mating surface where the gasket sits... haven't had much luck getting that more clean (in the past).