While I was working under the car on other projects I noticed that one of the bolts to the lower spring pan wishbone had stripped its thread, don't know the reason but this was the result

006 by MyPix on Talk Photography

now this alone would be an MOT fail in the UK, and more than that I just could not ignore it before she went back on the road

after some head scratching, and I didn't want to drop the subframe to fully remove the lower wishbone I decided to fix it using a ' Helicoil '
this involved drilling out the bad thread, tapping the oversized hole to take a stainless steel insert , and then putting back an original sized bolt , a new one at that

below is how I did it , first of all is the comprehensive Helicoil style kit I bought to do the job

001 by MyPix on Talk Photography

these are the parts required to replace a 3/8 UNF thread , an oversized drill , a tap , an insertion tool , the helicoil and a snap off bar for the insertion tang on the helicoil

002 by MyPix on Talk Photography

the bad bolt removed and the drill sent in being careful to match the angles in the casting

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the tap being sent home one quarter of a turn at a time with some cutting compound on ( I use mollyslip thread cutting compound ) then turn back each time to clear the swarf from cutting a new thread

008 by MyPix on Talk Photography

this is then cleaned and then the helicoil insert is installed , and the tang broken off when all the way in

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then the new bolt is inserted gently finding the thread , so not to cross thread anything

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and then fully tightened pulling up the spring pan nice and tight

011 by MyPix on Talk Photography

all in all , it took about an hour taking it nice and slow ,

BB

 

Nice man, hopefully this is inspiring to some people. So many people seem afraid of thread repair, but its really not all that bad.

 

Ive been using Helicoils for years. Both for my car repairs and at work. Great product that saved my butt and cash many times.

 

i have used Helicoils at times for iron/steel thread repair.

but for aluminum or soft metals i have had bad experiences,like pulling loose .

my personal preference today are the actual steel thread insert,a one piece design that is much stronger than a coil of wire!

close to the same labor and cost.

 

I've recently used a helicoil to repair a stripped wheel stud tapped hole in a rear wheel hub of my '90 Majestic (a truly special ride) and so far so good. I do agree with ronbros re helicoils in aluminum; the threaded inserts (Timeserts for example) are the only way to go.