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Sheared Bolts, Help Needed.
Posted: Wed Sep 05, 2007 11:18 pm
by mike071288
Hi
Ive got 3 sheared bolts on my m40 head, 2 have broken off completely and are flush with the head and one is just turning in the hole.
I have already asked zimmerbimmer1 about the new bolts but now i have the trouble of gettin the sheared bolts out.
The bolts are the ones that hold the rocker cover on.
I've been told to drill into the bolts and use a bolts extractor to get the bolts out, with alot of help from some penertrating spray.
Advice needed.
Thanks
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 12:23 pm
by mike071288
bump
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 1:35 pm
by Martinaston
The way you mentioned is about the simplest, just be careful with the drill and try not to hit the head because you'll ruin the thread.
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 2:40 pm
by mike071288
Cheers mate
Ill give it a go
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 3:47 pm
by Ajay325
spray WD40 as much as you can into the threads and let it soak for a few hours, worked for me...
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 9:47 pm
by dannyboy759
Use easy outs
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 9:59 pm
by fuzzy
thats the best way that you suggest although if one bolt is spinning in the hole the threads must be knackered .i dont know about these heads but if its alloy the threads in the head will be worn rather than the bolt so you will probably need an engineering company to machine and re thread the hole unless you can tap and die a bigger bolt in. i had to have 16 steel helicoil inserts added to my alloy head after ripping my exhaust manifold off destroying the threads. only cost about £60
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 10:33 pm
by mike071288
thanks for the advice guys
whats easy outs?
Re: Sheared Bolts, Help Needed.
Posted: Thu Sep 06, 2007 10:47 pm
by fugazi33
mike071288 wrote:thanks for the advice guys
whats easy outs?
Stud extractor set, drill a hole into broken stud wind in stud extractor & it should wind out the stud.
Re: Sheared Bolts, Help Needed.
Posted: Sat Jul 30, 2016 7:02 pm
by Avinit4
I've got 2 SHEARED exhaust manifold studs on mine.can anyone recommend a good value right angled drill as need to sort with Head staying n place. I've never done this before so a bit weary of it... But has to be done asap.. Anyl help much appreciated
Re: Sheared Bolts, Help Needed.
Posted: Sat Jul 30, 2016 8:58 pm
by Speedtouch
Alternative way is to MIG weld a nut onto the stud - the heat will help free it off.
Also, I would advise using PlusGas penetrating fluid and leaving to soak overnight - far more effective than WD40.
Note, you screw in Eazi-outs in the reverse direction (anti-clockwise thread); beware of cheap sets, as they are made of chocolate and will invariably snap with the slightest of force.
Re: Sheared Bolts, Help Needed.
Posted: Sat Jul 30, 2016 10:03 pm
by Topblag
fuzzy wrote:thats the best way that you suggest although if one bolt is spinning in the hole the threads must be knackered .i dont know about these heads but if its alloy the threads in the head will be worn rather than the bolt so you will probably need an engineering company to machine and re thread the hole unless you can tap and die a bigger bolt in. i had to have 16 steel helicoil inserts added to my alloy head after ripping my exhaust manifold off destroying the threads. only cost about £60
Welcome back man, I see you've relocated. It's been a while.
Re: Sheared Bolts, Help Needed.
Posted: Sat Jul 30, 2016 10:06 pm
by Topblag
If you are not confident, take the car to a decent workshop and let them do it. If you don't know what you are doing you can easily make a mess. For example, if you snap a drill or easy out, there's isn,t much that will drill through them. The good news is it's an m40 and there's loads around, I have a full engine and box sitting, for example.
Re: Sheared Bolts, Help Needed.
Posted: Sun Jul 31, 2016 7:34 am
by maxfield
Old thread alert.
Re: Sheared Bolts, Help Needed.
Posted: Sun Jul 31, 2016 9:48 am
by Brianmoooore
maxfield wrote:VERY old thread alert.
Re: Sheared Bolts, Help Needed.
Posted: Tue Aug 02, 2016 7:37 am
by milescook
Fair play to Avinit4 though, he's used the search function which is what we always tell people

Re: Sheared Bolts, Help Needed.
Posted: Wed Aug 03, 2016 8:18 am
by aimlessrock
unless your confident get a specialist to do it. One of the sub frame bolts in one of my merc 190's snapped flush a couple of years ago when doing a back end overhaul rather than try it I got a specialist who had the correct tools and removed it in about an hour.
Re: Sheared Bolts, Help Needed.
Posted: Thu Aug 04, 2016 3:31 am
by Avinit4
No threads spinning, when I got the right angled drill I'm good to go, altho going to practice on sheared wheel stud ( different Mota) And for the record it was a so called professional that sheared them. Itl be done at some point soon ish