valve cover thread stripping

[dane_lindsay]

over a few years of maintaining the valves, i managed to strip two of the six threads which hold the cover on. i used a torque wrench every time, but it happened nonetheless, and very easily. corrrect me if i'm wrong, but the head is made of aluminum, and the bolts are steel. very stupid.
   i assume(or hope) that this has happened to someone else, and would like to know how to repair it, or if it's even necessary. the gasket doesn't leak, so i assume there is enough pressure on it from the remaining 4 bolts, but just in case i lose a third, i humbly request any tips on the repair options. i've heard of helicoil, but don't know how it works, or if there is a better way. thanks

[The Buddha]

Yea I lost threads on 2 of them too this week ... Helicoil is the best solution ...
I am however yet to find a 7mm by 1.0 pitch helicoil in this damn town ...
Cool.
Srinath.

[starwalt]

Helicoil is a brand name for a thread replacement product designed just for this type of situation. They are sometimes installed initially, usually in aluminum casting parts, if the required torque of the fastener would exceed the torque maximum of the raw part.

With some thread replacement products, the damaged hole must be drilled out to a specific diameter OR a special tap-like tool is worked into the damaged hole. Then the thread replacement "coil" is installed into the reworked hole . The replacement coil has the same diameter and thread pitch as the original fastener and may in fact be stronger than the original.

I assume your torque wrench is not faulty or misadjusted. I still use a beam type torque wrench when applicable (old school - American system). I may have to cough up the bucks and get a clicker type metric for work on the GS. The new digital attachment for a standard socket wrench I saw at Sears looks cool too. Pricey though. Big $.

In your situation if it ain't totally broke, wait until you do a bigger job to install the helicoils. If the failed threads are any of the back three, on chassis work is probable. If any of the front three, I don't think there is enough room to do a proper job while the engine is on the bike. At least not without major disassembly.

There's your 98 cents change from a dollar (my 2 cents worth).  

[dane_lindsay]

forget this... i just found srinath's post regarding this very thing from a few days back... thanks for the help though.. great minds think alike...cool...

[dane_lindsay]

ah thanks doug, exactly what i wanted to know about the helicoil jive. i forgot to ask about the strenghth of the things. thanks again, i didn't see your message before i posted a second ago.

[starwalt]

Srinath, check a location of Applied Industrial Technologies. They used to be Dixie Bearings around here and the entire southeast. They cater to industrial (textile) support. Many textile machines are from Europe. They list Helicoil as being in their product line.

Give 'em a call. It may pay off. :dunno:
Results of search near Charlotte, NC

http://web.applied.com/
--------------------------------------------------------------------------------
Location #0262
2217A Distribution Center
Charlotte, NC 28269-4264  
PH: (704) 596-0898
FAX: (704) 596-4261
Email: sc0262@applied.com

Location #0224
2501 N Chester St
Gastonia, NC 28052-1807  
PH: (704) 866-9111
FAX: (704) 866-9612
Email: sc0224@applied.com

Location #0286
620 Buffington Rd
Spartanburg, SC 29303-4716  
PH: (864) 583-4583
FAX: (864) 585-4161
Email: sc0286@applied.com

[The Buddha]

OK Cool... that first one should be right around here somewhere ...
OK starwalt ... you asked for it so here goes ...
I have done all the thinking and pretty much know what to get ... just need a best place to get it at ...
I need a gates polychain place ... I need a 8mm pitch 36 tooth 21 mm wide pulley. Now further ... what are the different types of centers its available in Dont talk me out of it ... my GS is getting a belt drive ... as soon as I spare the $$$ and if I haven't hocked the 47K mile GS by then ...
Cool.
Srinath.

[starwalt]

Belt drive would be a cool mod. Front/rear pulley alignment would be critical though. I've got big Harley parts for my Vortex project but they are way too massive for the GS.

I was looking at a full line pdf from Applied but can't find it now. I seem to remember seeing Gates listed. This would be considered a Power Transmission product. They can probably get you any Gates product if you have a Gates part number. Go to Gates site and research it there then go to Applied. I registered at their site but won't have access till next week. Most industrial supply stores aren't open on weekends.

With Gates #s you could try ebay. There is a lot of industrial stuff there.