Re: Miss Lucy Threads ‘serves’ 5 BIG studs
With respect I have a few comments on this article to clarify a few points that are open for interpretation.
Originally Posted by waldig
I have used antiseeze in the past and that was some good and some not what you wanna do.
As stated you should not use any lubrication on the bolts, this leads to over torquing of the bolts as they are easier to tighten. This can lead to the threads deforming and stripping, the bolt is also closer to its shear load. Later in the article 90ft/lb is mentioned, the specification is 80ft/lb.
With lubricated threads the 90ft/lb would stress the bolt and threads higher than 90ft/lb without lubrication.
To drill the holes, I drilled each hole out three times using bigger and bigger bits to allow the metal to be cut out without snagging or going off center with my trusty black and decker drill.
I would not recommend anyone to drill and tap these holes free hand, it is essential that these holes maintain the correct centers as the original and be drilled parallel to the wheel axis.
If they are not true then the bolts will exert side pressure on the spherical seats in the wheel and this could lead to cracks in the area of the holes.
Drills that are not accurately sharpened will wander away from center and produce oversize holes. When drilling with a hand drill it is nearly impossible to drill truly square, a good drill will try to self center to some degree but the operator is fighting the weight of the hand drill and this 'feel' is lost. Tapping the hole free hand is also not a task to be tackled by the novice, attempts to straighten a tap which is wandering leads to a loosely tapped hole that will not satisfy the Helicoil requirement.
Drilling and tapping these holes should be done in a milling machine by a skilled operator. The holes would be located truly to the hub axis.
Loctite is not required in these holes, when the tapped hole is to specification the correct face to face contact of the Helicoil and base metal is ideal.
Helicoils flex and have some bit of give which share the torque and pull out forces equally.
Under load items flex if they can to relieve their loads, they do not flex to take on loads
BTW the 14mm studs don’t fit in the 12 mm wheels because the ball of the stud requires a matching hole in the wheel. Some of the bigger Mercedes use 14mm studs. Not us……..
The 14mm Helicoil inserts would also not have sufficient depth in the hub to be inserted as they require a minimum thickness of 14mm (.550") to meet the minimum specifications.
The 14mm studs have a 14mm radius spherical ball seat.
Last edited by onehundred80; Aug 26, 2010 at 01:13 PM.