S52 cam cap stud pulled out of head.

[ArcticM]

Glad I found this. Have been plagued by this in my numerous top end jobs and have either had to resort to helicoils or run the car at lower than ideal torque on a few nuts.

[ptesta454]

Okay, I tackled this today and BOOM, it WORKS. Big Big thanks to tjM3 for this. Turns out there was no helicoil on the old stud, just stripped aluminum from the head!

A couple things to report. There WILL be metal shavings with this repair which can be recovered with brake cleaner, a rag, or a shop vac. Just be careful with them.

The bearing ledge will not fit over the new 5/16" stud if you have more than one which was my situation. See picture below. I had to tap cylinders 3, 4, and 5 for a total of 3 new studs. In the future, I am going to do this to all 14 because it works and is much stronger, but I will do it with the head removed.

So, my advice, pull the bearing tray with magnets and a metal rod, tap the new stud, remove stud, put bearing tray back on, and put stud in through the bearing tray, then bearing lobes, and tighten down. This will ensure the bearing tray is in place before you run into clearance issues like I did.

Also, my 3 bearing caps could not clear the new 5/16" stud, so I simply drilled them out off the camshaft with a 5/16" titanium bit.

Finally, when cutting your grade 8 threaded rod, make the length just a smidge longer than stock, and miter the edges with a flap disk to create a little bevel so the rod can catch its threads.

The cam is in and everything is torqued to 11 foot pounds. I think I'm good! Again, thanks a lot tjM3.

IMG_3844.jpgIMG_3843.jpg

[tjm3]

I guess that works but it's a bit more work.
My method was meant to be done without removing the cam and bearing ledge/lifter tray by removing the cap and going through the tray with the tap, which is why a pulley tap is needed.
Whether you use any of the Heli-coil, Timesert or the 5/16 stud methods you still end up with more thread area and holding strength.

[ptesta454]

Yes and that method will work just fine. In my case, I had already pulled the camshaft and simply wanted the lifter tray out of the way to reduce the metal shavings.