Broken Rocker Cover Bolt

[Anonymous]

#2040

Hi,Ok, here's an engineering challenge for you! While I was tightning up my right hand rocker cover, the rear top bolt just kept turning and not tightning. I took the cover back off and a lump of the casting that has the thread in fell into my hand. The bit that is fell out is 50% of the available thread and I'm at a loss as to how to repair it. People have suggested helicoil, but I'm not sure there is enough existing thread to hold it. Someone has suggested cutting a 6mm thread inside a larger bolt and screwing the larger bolt into the remaining metal.Has anyone had this type of thing happen to them? Does anyone know who would be able to fabricate such a bolt?Any suggestions gratefully accepted!DA

[Jim Young]

#7670

Doesn't fitting a helicoil involve drilling and tapping a larger hole for the helicoil to screw into ?Of course this would only be possible if you have enough metal on the casting to do it.Best of luck fixing it, I know how you must feel when things like that happen, that sick feeling in the pit of the stomach, usually accompanied by some choice words.  😮

[Dave Ross]

#7671

You should be able to have it welded and re-tapped. They are little more than hand tight. I use the torque wrench or stop when the rubber seal shows signs of compression. Of course, the crack could have been the delayed result of a tip-over. Check out the ads in the back of Kiwi Rider magazine for place to go for welding.

[Anonymous]

#7672

Just helicoil it. Much easier, and a permanent solution. Used to do it alot on Magnesium aircraft gearbox casings. Simple, quick, strong. Select the correct helicoil kit, and all the tooling needed should be in it.

[Anonymous]

#7673

Loctite sell a “Form -a-Thread” repair kit or Delo sell an alloy repair kit that can be drilled, tapped after 90 mins if you decide not to helicoil. Good luck.

[Dave Ross]

#7674

What's the latest on the rocker cover saga? Did you get it repaired alright?Cheers,Alex

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