Valve cover thumbscrew stud hole stripped

[zachmac]

I swear I searched and searched before posting. Can't believe this one hasn't come up? Anyway, my front driver's side cam tower is stripped where the stud screws in under the valve cover that the thumbscrew screws onto to secure the cover. I assume someone else has faced this? I guess it isn't just teenagers with Chevelles (me back in the day) that overtighten valve covers!

I assume I have one of three options (assuming I don't want to source a new cam tower and go through the hassle of changing it out: I don't ):

1) helicoil but probably hard to find M6 1.0 helicoils and there isn't much metal to work with there. Sureas hell don't want to crack or break that rib.
2) JB weld. Will this work in an oil environment?
3) Try to find a 25 mm long stud that is M6 1.0 on one side and something just slightly larger on the other, carefull retap cam tower hole making sure to catch any shavings, etc.

Anyone done this fix? How?

[klweimer]

You can get M8 x 1.25 studs from McMaster-Carr and then re-tap your thumbscrew to the same thread. 1/4-20 thread is in between 6 and 8 millimeter, but you probably don't have enough meat left for that small an increase in diameter. You can also get M6 x 1.0 threaded inserts there as well, but it looks like the OD on them is all about 10 MM.

[zachmac]

I'm leaning toward the JB weld. Am I crazy?

[AFRetired]

You might give Loctite Form-a-thread a try http://www.napaonline.com/Catalog/Catal ... 0195609250

[TStark]

Timesert makes an m6x1.0.

[DieselSpider]

You might be able to just use a low temp Aluminum Welding Rod.

http://www.harborfreight.com/8-piece-lo ... 44810.html

Video showing how to use it to replace a broken off casting. Similar can be done to fill and re-tap a stripped hole when there is not enough material to enlarge and insert a helicoil. At a working temp of 600 to 750 degrees you can do many parts in place.

https://www.youtube.com/watch?v=q1ofGPbOZWU

[zachmac]

You might be able to just use a low temp Aluminum Welding Rod.

http://www.harborfreight.com/8-piece-lo ... 44810.html

Video showing how to use it to replace a broken off casting. Similar can be done to fill and re-tap a stripped hole when there is not enough material to enlarge and insert a helicoil. At a working temp of 600 to 750 degrees you can do many parts in place.

https://www.youtube.com/watch?v=q1ofGPbOZWU

Thanks but the tower is on an assembled engine in a car with lots of motor oil bathing the cam. Maybe open falmes and welding isn't the best approach. I think I'll give the Locktite From-a-thread a shot.

[DieselSpider]

You might be able to just use a low temp Aluminum Welding Rod.

http://www.harborfreight.com/8-piece-lo ... 44810.html

Video showing how to use it to replace a broken off casting. Similar can be done to fill and re-tap a stripped hole when there is not enough material to enlarge and insert a helicoil. At a working temp of 600 to 750 degrees you can do many parts in place.

https://www.youtube.com/watch?v=q1ofGPbOZWU

Thanks but the tower is on an assembled engine in a car with lots of motor oil bathing the cam. Maybe open falmes and welding isn't the best approach. I think I'll give the Locktite From-a-thread a shot.

A piece of steel flashing and some mild heat from a plumbers torch will work many times. Its below 750 degree brazing work which you can many times do on a raised stud on a tower without disassembly. Only do whats in your comfort level though to keep it safe.

[aevansgatech]

A quick side question: Do I need to do anything to remove the valve covers other than remove the 4 screws? Does oil reside in the chambers while at rest?

[RRoller123]

Just the 4 screws. there is a lot of oil in there but it won't run out if the car is on level ground

[aevansgatech]

Thanks!

[zachmac]

Going to go with a M6 1.0 helicoil insert but my question now is where on earth do I finds a replacement stud? I can find 23 and 27 mm length with unequal length threading all daylong on the internet but the ones in the car (and that I need to replace) are 25mm length and even thread length on either side of the raised center portion of the stud.

[RRoller123]

www.belmetric.com and www.allensfasteners.com may have what you need. Belmetric is highly regarded and has been recommended by many. Fastenal may have it too, but I have been very disappointed with the retail selection here at their retail outlet in Plymouth. Fastenal online probably a lot better.

[zachmac]

Looks like I will have to buy a 32mm stud and cut to desired length.