lorenolson888

Hi All,

I ran into the problem with the cam bolts breaking on my 86... Two broke, many came out clean and for about half of them the spacers are still in there... Those are not going anywhere... I will replace them with the update bolts at a later time when the engine is out and apart...

The two that broke are at the top of the drivers side head so I can drill them dead on...

Wondering if anyone has any advice on fixing the broken ones... drill and retap?... use an easy out tool?... heat with a propane torch??? In the past I have found that trying heat and easy out is kind of a weak second chance... works sometimes but I have had the easy out break on me and leave a piece of hardened steel in the end of the bolt I am trying to remove.... not fun.... Crasftsmen has a good tool but they are expensive... they put a weak point in the middle f the tool so if it breaks you can usually back it out...
Could I just drill it and use a starting m6 tap and follow with an m6 bottoming tap??? This may be the only sure fire way...

Any advise is greatly appreciated...

LO

Daniel Dudley

See if you can get your hands on some counter clockwise drill bits. try drilling a small hole in the center of the bolt and keep going larger. You can sometimes get lucky and the ccw drill will spin it out for you. This is a tricky situation. once you wander into the aluminum you are screwed, so easy does it. Small pilot bit and center punch help. Do you have any friends who are dentists?

jim morehouse

I found a tool called Quikcenter that looks like it does a nice job of centering and drilling out the old bolt heads..works w flush, below and protruding bolts. I haven't used it yet but it comes in various metric sizes and may work for you. Do a google search. Let me know if you can't find it and I'll try to find the site again.

Jim

lorenolson888

I spoke with Marc Thomas and he also mentioned using ccw bits... Propane torch too... This sounds good... if I can center the hole and get it close to ~4mm (bolt is an m6 thread)

Marc also mentioned taping on the bolt heads with a hammer before touching the cam covers... probably a good idea.... mark mentioned that if it does not turn easily dont force it ever.... they take very little torque to break off

I am a bit afraid of the ccw easy out type tools becaue they are usually pretty hard and brittle... I used one from craftman... $35 a set of 4 sizes and it worked to pull out a chunk of a screw but on the next chunck it broke... I was barely able to get a ahold of it and remove it... At least their is a weak point that the tool broke at (I think that this weak point is intentional). A cheaper one from sears was way worse and it broke very easily... (a black spiralling thing)... So I think that I will avoid trying special tools... a peice of hardened tool steel stuck down the hole it a lot harder to remedy then the broken bolt...

V-Fib

If you haven't removed a few broken bolts in a previous life, be very very careful. I've found some things are better left to a reputable machine shop. The trick is know the when to do it yourself and when to let the professionals handle it. When I had my heads reworked, they took 3 bolts out without messing up the holes/threads. Just my .02. Good luck, I've had my share of broken bolts that I removed too.

Big Dave

I couldn't agree more. What's worse is that they may actually feel like they're turning out and then just snap. The spacer I removed felt nearly the same as the spacers I snapped.

atari_st

I just got done fixing your exact problem. Many will think what I did was crazy...but I had NO choice other than pulling the engine to drill them out. Since I have never removed a broken bolt before, I had a freind that has done MANY. The drivers top left front was not too bad. We applied heat, tried easy outs, drilled down the middle of what was left of the spacer....and it would not break free. We ended up trying to get the spacer to grab hold of what was left in the hole (Nice and smooth)...and it actually worked. Now...for the one on the passenger side bottom next to the strut housing was a PITA. I bought a 90 degree air plane tool that hooks up to a standard drill. We tried and tried.....could not get it to center since we only had 2 1/2 inchs of space to work with. We ended up getting a hole made...used a tap....and the dang new spacer did not go in straight. I ended up putting a small washer on the spacer to try and level it out on the head...even though it was way off from the original one. I just put on the covers today and was able to get the bolt to go in and torque to specs. Now....once I get the TB/WP done and the car running again....I will find out if the gaskets sealed. Good luck... I hope to never have to pull the Covers again....unless the engine is out of the car.

mspiegle

I recently purchased a set of extractors from sears. With my recent experience (removing a snapped bolt from a wheel hub), they were stronger than my drill. I have craftsman's top-of-the-line 600in/lb coordless 24v drill and the reverse screw the holds the chuck assembly to the drill snapped clean off during the extraction process. The extractors are hardened steel I believe. Sure, if they break, you're screwed.. but you've got to be doing something wrong to make them snap.

lorenolson888

I got some left handed drills... Luckily mine are on the top and not next to the side wall like ataris. The chips did not spin out like some have suggested would be ideal... I am using a 4mm bit... the thread is an m6...

I think given the trouble you are having maybe one of those thread replacement products would be best..

I took the afternoon to research using acid to dissolve the remnants of the bolt... aluminum sulfate (powdered alum) has been used in a super saturated and boiling soluting to disolve hardened steel taps and bolt from non ferrous parts (brass aluminum etc) in a couple of hours!!! (Kind of interesting) but the problemm is I cannot boil my head ... and at room temp the solution would not be a high concentration... I am a scientist so I kind of think this way...

Mike the sears tool is a good one i agree the best i tried... and my corded drill could not break it free... I got creative and put a deep 4mm socket on the drive end of the tool... It actually was able to remove a chunk of the bolt... but there was still a chunk left deep in the hole. When I went for the next chunk the tool broke... The sears tool has a thin section that it broke at... so it was easy to remove ... another tool from sears (spiralling gizmo) was way weaker.... it broke right way.... Sucks... These bolts we are talking about are m6 and have been there for a long time... Also the cam cover bolt are notoriously weak any way... wheel hub bolt not sure which you refer to but they are probably larger and a bit easier to work with so a tool is probably a good idea...

Mike you are lucky that you never got around to the cam cover bolts on your 86...worst design flaw i have seen yet... So your new S4 will be a bit easier... 928gt.com is going to reman the bolt in a new material so these will also be a bit cheaper than the 22 to 29 each!!! I will PM you sooon... Been real busy

LO