Head Stud Repair Tips

[Ray from Indiana]

Looks I'm on a bad luck streak.

The situation: 82 R100 with 48k miles.....pulled head stud, left side, upper front, yeah the common one for stripping.
I know the torque wrench I use clicks at 4 ft-lb lower (actual) than setting ( safe side ). I always 5 step may way up to 25 ft-lb indicated when re-torquing and when I reach 25 it is actually 21 ft-lb.

Retorquing before valve clearance setting and only got torque of 18 ft-lb, when I went for the 25 ft-lb, there were a lot of curse words emanating from my garage.

I dunno- maybe PO started the raod to stripped or maybe there is some validity to the sthread fatigue theor for these studs. Can't see how my 21 ft-lb would have cause a pull-put.

I plan on using BMW's long reach repair coil and I know about keeping swarf where it doesn't belong after teh drill/tap routine. Any additional tips welcomed as I haven't done this repair on a BMW before ( but have done plenty if helicoil jobs ).

I'll start this job as soon as I gather the stuff

[Garnet]

Frog has a great pictoral how to on the interweb somewhere.

[Ray from Indiana]

I found the Frog link in the archives but nothing shows up after activating the link

[Garnet]

Send him a PM. I'm sure he still has all the info. It was a very good write up.

[Major Softie]

As far as tips, just keep in mind how critical it is that the hole be drilled out and tapped perfectly perpendicular to the mating surface.

[ME 109]

As far as tips, just keep in mind how critical it is that the hole be drilled out and tapped perfectly perpendicular to the mating surface.

Absolutely.
We don't want a Moto Guzzi, do we.

[Frog]

Thanks for the kind words guys.

I have not been on the forum much these days, as I have been too busy wearing out tires



I am not sure that you want to follow in my footsteps on this repair, as I decided to install case savers in all eight stud holes, rather than just fix the one stripped thread. I never wanted to do it again and plan to put many more miles on this bike.

I am happy to share my experience or answer questions.

The easiest solution would likely be to install the long helicoil or the like. As for debris, I had both cylinders off, so was able to install a vacuum on the back side of the hole (some are blind and some are not).

Here are my photos with some comments:

https://picasaweb.google.com/1030509870 ... directlink



PS-thanks for the PM, it goes to my e-mail and brought me back to answer your question.

Good luck