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Stripped head on allen bolt holding 2009 CPU heatsink - help!

les24preludes

les24preludes

macrumors regular
Original poster
Feb 6, 2011
114
5
I'm trying to remove the heatsink from a Mac Pro 2009, 2.66 quad core, after upgrading from 4.1 to 5.1. The intention is to fit a X5677 processor. The bolt in question is the single one on the left looking at the motherboard, not the four around the CPU itself.

The stripped head is a problem and I can't see a solution. I asked an engineer friend and he said the only way was to drill out the head. We talked about using a #3 allen/hex key with superglue on the end, but if it's a captive bolt I may end up in even more trouble. He suggested a 8mm drill bit, which is the diameter of the allen bolt head.

I removed the motherboard from the tray to see if I could unscrew anything from underneath, but it looks like the base part of the nut is glued into the PCB.

I can only trust that if it were drilled out I could then find a solution to re-attach it. I don't think it's that critical, since it's the 4 bolts around the CPU that hold the heatsink tight to the processor.

Can anyone suggest a solution for this?
 
The only other option that comes to my mind is putting some harder rubber bands on hex key, to simulate the glue, but I doubt that grip will be strong enough.
Or maybe hex key with rounded head will be able to do the job (or one tad bigger, say 3,5mm)?
Stripped screw head is major pita, but I would leave drilling as last resort.
 
les24preludes: This video shows all standard techniques for removing stripped screws.


This other video shows some tools made for the job.

[doublepost=1489240775][/doublepost]And yes, Apple glues their hex heatsink bolts with Loctite to prevent them from rattling and coming loose over time, so that will make things harder. But the 2009 machines have dried over so many years that the glue breaks quite easily. Mine needed almost no force at all to snap loose.

I know for a fact that you can solve this. Sorry to hear about the trouble though.
[doublepost=1489240921][/doublepost]By the way I am assuming you are talking about the heatsinks, which use 4 very long hex bolts:

processorcard4.jpg
 
It's this allen bolt here. It's pretty inaccessible, so a lot of the usual tools won't go in. It would drill out. question then is what to put in its place. This is the quad core version so just one heatsink.
 

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I had a similar problem 2 days ago. However, I own the dual core Mac Pro, and I was having the problem with the lower left one of Heatsink B. It turned out, that it wasn't a hex screw, but a Torx screw. All 7 other screws were hex screws though. Now I don't know the exact screw you are speaking of, since the dual board is a little different, but if it is an "invisible" one as well, you might wanna try out a torx screwdriver!
[doublepost=1489241792][/doublepost]
les24preludes said:
It's this allen bolt here. It's pretty inaccessible, so a lot of the usual tools won't go in. It would drill out. question then is what to put in its place.
Click to expand...

Ha, good timing. Try a torx! Pretty sure it'll work! ;)
I spent HOURS trying to figure out how I could get my "stripped" hex out of there - only to realize it was a freaking torx.
 
I wish I'd seen this post earlier! I lost patience and got the angle grinder out and fitted it through the slats of the heatsink and took the head off the screw. This was surprisingly successful and didn't seem to do any damage apart from wearing away a little of the transverse slat. Heatsink came off so now we're in business again. The bolt was really tight and it took a mole wrench to turn it, so hardly surprising it was stripped by the allen key. The thread looks to be M3. Solution appears to be to use a long M3 screw right through the heatsink, secured by a washer on top - not too tight obviously.

So..... after all that, onwards with fitting the X5677. I used a camera lens puffer to blow away any swarf - hope it all blew away.... We'll find out if it all works when it's all fitted back again.
 
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Hooray! It all looks so far like it works. Fingers crossed. Processor now 3.46 instead of 2.66. Geekbench 3 went from 1942 and 7294 to 2533 and 9918. Seems a worthwhile gain.

What should have taken me an hour took me a total of 5 hours. I'm a bit proud of myself for bodging all that lot. Moral of the story is that an angle grinder works when all else fails. Hopefully this post might help some hapless soul who finds himself or herself in the same situation!

Thanks everyone for your input!
 
I think you would have needed an extension -and a very thin one at that- but I used this for another project (a laptop case screw that got stripped by a cheap Torx 4 screwdriver from home depot and it was good for only 4 or 5 screws (so yes, I needed two of the screwdrivers to do the whole laptop) that being said, as cheap as the tool was, if it hadn't killed the one screw...) and it takes patience and a slow drill but (https://www.amazon.com/gp/product/B000Q60UOO/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1) worked like a charm and the tool is good enough that it doesn't even look like it has been used. The thing is that you have to follow the instructions and BE PATIENT or you will end up like the reviewers who gave it one star. When it works, it will work suddenly but the smaller the screw the more often you need to check if the tool will grab the screw and be careful not to heat the screw.

It worked with a M2 Torx and a reviewer used it on a MacBook Air so people with laptop screws that are stripped are covered but driving it in the heatsinks... if only the hole was bigger!

OP: so you were able to replace the whole bolt? Where did you get the replacement bolt and what was the size and the pitch that you where able to get?
 
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It's an M3 thread, so fairly simple. I actually made up a long bolt by screwing together a few hexagonal spacers.

http://www.newark.com/productimages/standard/en_US/4264777.jpg

I took out the spring first. Then I screwed the bolt I made up into the base. I then used a wide washer on top to hold the bolt onto the heatsink, and secured it with a short screw which screwed down into the top of the bolt. Worked fine and didn't project too much, so the whole PCB and heatsink went back in OK.
 
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