Over tightened Cap Screw!

[ultrarunner]

I wouldnt reccomend that...in the future this "could" happen again.... HeliCoil is the way to go...same size bolt, AND a HeliCoiled insert is usally STRONGER then a plain tapped hole in aluminum. Thats why most hi-perfomance heads like Edelbrock come FACTORY with helicoiled inserts.
In the racing community I've also seen people helicoil the valve cover bolt holes on aluminum heads because the aluminum just doesnt stand up the repeated removal/reinstallation...with helicoils they last forever...

Because this is a "commonly" removed part, I'd probably go ahead and helicoil both of them and be done with it...

If it is a through hole a bolt and nut would be the simplest...

At the machine shop we seldom used helicoils... almost every job spec used a threadsert product that had built in tangs to lock the insert into place...

 

[Spudland_Dave]

If it is a through hole a bolt and nut would be the simplest...

At the machine shop we seldom used helicoils... almost every job spec used a threadsert product that had built in tangs to lock the insert into place...

I must apologize...I use the word helicoil similar to Kleenex & QTips....When I say Helicoil I dont mean a specific brand/style/part, etc...
I recently used some Recoil brand "Keyserts" and I thought those were really slick & nice...

 

[ultrarunner]

I must apologize...I use the word helicoil similar to Kleenex & QTips....When I say Helicoil I dont mean a specific brand/style/part, etc...
I recently used some Recoil brand "Keyserts" and I thought those were really slick & nice...

No apology necessary... Keyserts is the name I couldn't remember... thanks for the info!

 

[kennyd]

If it is a through hole a bolt and nut would be the simplest...

This is a cover...how the heck would he get a nut on the backside if it was a through hole

 

[kennyd]

I'm just starting to do my reasearch. Would I want to use the free running type or the screw lock type? Also which finish? dry film lube or no finish? The bolt is M8X20, how do I determine if it is a fine thread or a coarse?
You may have figured this out already but this is new territory for me and I want to get it right the first time!

This is what a kit looks like: M8 Helicoil. It does not come with a drill bit though...There are plenty of similar product on the market, some of which I am sure you can source locally. Try a google search of "m8 thread repair" for thousand of hits. Some "kits" do include the drill bit also. Most likely it is a 1.25 course thread.

 

[ultrarunner]

This is a cover...how the heck would he get a nut on the backside if it was a through hole

Some automotive auto transmission pans have the pan bolts going through a flanged lip... some of the bolts go into blind holes and some in through holes with the threads visible on the outside of the case...

I've never worked on any John Deere larger than a garden tractor... just mentioning different possibilities to work around a stripped bolt hole...

 

[Wayne_H]

I'm no expert, but I have put a few heli coils in. I might suggest you make a jig for the drill to keep it perfectly straight, and so it does not wonder and make a larger hole than you want. If you have a drill press you can make somthing that will secure with the good bolt, and make sure this hole is at a 90 degree angle with the flat part.

Wayne

 

[Piedmont]

Thanks all, I won't get to this until the Thanksgiving weekend but I will post at update. Is there a way to find out if the 8MX22 cap bolt is a fine or coarse thread?

 

[kennyd]

Is there a way to find out if the 8MX22 cap bolt is a fine or coarse thread?

Not easily, but you can assume it's the course 1.25 thread. Most are-especially when used in aluminum.

 

[Piedmont]

Not easily, but you can assume it's the course 1.25 thread. Most are-especially when used in aluminum.

Thanks Kenny