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Post by johnprestwich on Nov 10, 2008 15:39:52 GMT -5
Just did oil change for first time on my '78 import from sunny California. Poor thing must be wondering what the hell is going on with the weather here in Scotland. Anyway, despite careful preparation of surfaces and use of new gasket she just kept weeping a little oil. So I tightened everything up again, and again...... Yeah yeah, I know. Predictable result, sudden give in one of the bolts and slight increase in rate of oil loss. Bugger. I've left everything as is for now because I want to be able to ride, but one drop every couple of minutes is obviously not sustainable for very long. Don't think I've busted the bolt, feels more like stripped the thread in the casing. What are my options? Is there enough metal to drill and tap out to 5.5 or 6mm and is this a realistic DIY option? Or should I be seeking professional help with a helicoil? Any other ideas? All advice gratefully received. Thanks.
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sven
Full Member
Posts: 166
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Post by sven on Nov 10, 2008 15:45:41 GMT -5
Get it helicoiled and remember:
"Nach fest kommt ab!"
(after tight comes torn?)
Regards
Sven
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jeffz
Full Member
Posts: 215
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Post by jeffz on Nov 10, 2008 17:09:02 GMT -5
You could try using a slightly longer bolt to get you by until you can heli-coil it. There may be a few good threads left further in the hole. I had the same problem, but I haven't gotten around to heli-coiling it.
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Post by wotavidone on Nov 10, 2008 17:38:49 GMT -5
I add a little bit of good old Permatex #3 nonhardening aviation gasket cement, each face of the gasket. Love that stuff.
Mick
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pcnsd
Full Member
Posts: 113
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Post by pcnsd on Nov 10, 2008 22:20:24 GMT -5
All the others are great suggestions for repair, but why is it leaking in the first place? Best to find the cause so you don't chase the bolts around again. Ps. Man, have I stripped a lot of bolts in my time. If tight is good, then tighter is  ? ;D PC |
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Post by johnprestwich on Nov 11, 2008 16:44:44 GMT -5
Thanks to all. Plan is to let local bike shop helicoil it as they're used to this sort of thing and can do the work by the end of the week. But the point about trying to figure out why it is leaking in the first place is well made. Perhaps my surface prep was not quite as meticulous as I thought. Also think it may be time to invest in a torque wrench!
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Post by wotavidone on Nov 11, 2008 17:18:44 GMT -5
Can't beat a torque wrench. Lotta people reckon you should be able to feel everything, but hey if you aren't sure a torque wrench takes all the guess work out of it.
And permatex number three makes sure you don't have any leaks, all the bolts are doing then is holding the cover on.
mick
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Post by solo2racr on Nov 11, 2008 20:21:05 GMT -5
As a general rule, one can get a fairly even (2-3 ft/lbs)torque from one bolt/nut to the next. The problem is that they have no idea what the torque value is. The good thing is that it is more important to be even than some torqued correctly and others way off.
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Post by StewRoss on Nov 12, 2008 2:18:28 GMT -5
Are you talking about the sump cover? If so they're not that hard to crack by doing the bolts up hard...that will then cause them to leak. Helicoil is probably the answer, as is welding and re-tapping...although slightly more problematic. The threads will also strip out if you use too short a screw...although that leaves thread further in that might be able to be used with the correct length screw... SR  |
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Post by caferacercarl on Nov 26, 2008 3:49:58 GMT -5
Stew is right, they usually crack, do the bolt up and you may find the crack appears, sumps cost less than having a shop heli coil a thread, [well in Australia anyway] and with the new one use an alloy washer,they are softer, cheers as always.
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? ;D
