Author Topic: Major disaster - need advice (Read 15111 times)

awolff280sl · « **on:** July 12, 2009, 18:41:11 »

I'm in big trouble. Today I was re-torquing the head in preparation for our trip to Ohio. 2 small coolant trails have recently appeared on the front driver's side of the block. After doing the 14 10mm bolts, I went to the 4 smaller bolts at the front of the engine. Upon trying to loosen one that secures the chain guide bracket, the bolt head snapped off!. To make things infinitely worse, that little allen head fell down into the chain housing where I can't see it or retrieve it with a magnet.
Based on the little I know, I bet the whole f*ing engine has to come out?

jameshoward · « **Reply #1 on:** July 12, 2009, 20:13:46 »

Andy,

Gutted for you.

When was the last time you did the bolts, or when did someone else do them? This has always been my fear about doing bolts that would otherwise be fine. It's what's stopped me doing mine until now.

I really hope it isn't as bad as you think.

Good luck.

James

waqas · « **Reply #2 on:** July 12, 2009, 20:23:55 »

Hello Andy,

Sorry to hear about your woes.

Before you panic too much, here are some ideas:

The bolt can probably be drilled out, whilst carefully covering the surrounding so metal flakes don't remain inside the engine.
Search around for a borescope so you can peer around the lower front of the engine to look for the bolt head. Once located, you can try either a magnet or a claw arm. I recently bought a great extending magnetic pickup tool with an LED on the front.

Good luck and keep us up to date!

awolff280sl · « **Reply #3 on:** July 12, 2009, 20:56:25 »

Thanks for the sympathy. James, I had previously only retorqued the 10mm bolts, never the small ones. Would not surprise me if they hadn't been touched in 40 years.
Waqas, thanks for the info. I will see what I can do and keep you posted.

Shvegel · « **Reply #4 on:** July 13, 2009, 00:21:36 »

Maybe you can pull the front oil pan and fish it out that way. It is possible it is in the pan already so it might be worth a fishing expedition through the drain plug hole.

Ron · « **Reply #5 on:** July 13, 2009, 00:47:01 »

Sorry to hear of this problem. Whatever you do, do NOT turn the engine at all. That bolt head, if it were mine, would be resting on the timing chain and crank gear, ready to be rolled in between the two. I would pull drain plug and fish around with one of those magnets on a rod. Or remove the pan. Also, there is a tiny flash light now, LED, on the end of a rod, that will drop down into the chain cavity so you could see if that bolt head is sitting somewhere.

BTW, years ago I dropped a small bolt into an oil drainback hole in the head of a Mazda. The bolt fell into the rear of the pan. The pan had baffles and also the pan could not be removed with out pulling the engine up above a frame member. I was able to fish out the bolt with a magnet on a flexible rod, after several hours.

And, I run Fairmont motorcars (http://motorcar.winkworth.us/ is one of my friends in this, and I have a car like the one shown) These cars are water cooled and are full of steel bolts in Al waterjackets, and Al heads. We've all had broken bolts such as yours, because the machines are usually over 50 years old. It is not too hard to get this fixed (extract and replace), but I highly recommend you find someone who has done it many times. I can do them now, and your bolt is in an easy place to get to, but I would not do it on an SL, I'm not skilled enough.

As the SLs age, that Al head and steel bolt stuff is all going to be a problem (dissimilar metals). It is really nasty when water is involved, and the bolts end up rotten stumps. UGH.

Good luck and let us know what happens.

Ron

PS There is a local welder who tacks a piece of steel onto the stump, then heats the head to get the bolts out. I would not watch that, nor do I think I'll let him do it to my car.

And, since my engine is open right now, I'm going to take those bolts out and put some "never seize" on them.

awolff280sl · « **Reply #6 on:** July 13, 2009, 01:07:15 »

Thanks for all the good words. The first thing my trembling hands did when this happened was to disconnect the battery.
The oil pan will be checked. As far as bolt head retrieval, I'm going to contact some local safesmiths (the guys who legally crack safes). I was told that these guys work with flexible scopes and have experience in these kind of spaces.
I also contacted my guy who is a mobile TIG welder. He says he can pinpoint weld to the top of the broken bolt while only "warming" the surrounding block, then hopefully turn it out. Most have advised against trying to drill it out.
I will want to remove the chain guide and bracket for access. This looks pretty straight forward to do. Nevertheless, is there anything I need to know regarding its removal and replacement?
Thanks.

ja17 · « **Reply #7 on:** July 13, 2009, 03:59:45 »

Hello Andy,

Not such a big deal if you proceed cautiously. as mentioned do not rotate the engine. Try a long flexible magnet tool first. I agree that the parts often end up on the crankshaft sprocket. Turning the engine will bend or break something if this is the case. A masgnet will usually do the trick. I have one on a long flexible, bendable wire that works well let me know if I need to mail it to you. You will find that the chain tensioner sprocket is in your way but try to work around it.

Sorry I missed your call today. Call me on my cell if you like. Email me for the cell number ja17@att.net

The broken bolt should not be a problem. You can get a backward drill bit which will wind the broken stud out as you drill. These small front bolts are not holding back any pressure like the other head bolts. Everyone should be gentile with these they are only 6 mm diameter! The other large head bolts are 10mm diameter.

awolff280sl · « **Reply #8 on:** July 13, 2009, 20:59:36 »

Found and removed the broken bolt head. It was sitting on top of the crank sprocket, just where Ron predicted. I needed a small enough magnet on a flexible wire. Its spring washer was fortunately still wedged on it. I needed to remove the chain guide bracket to get right on the broken bolt, and I could remove remove the other bolt without it snapping. Curiously, that bolt did not have a spring washer.
I will first try to reverse drill the broken bolt shaft. If no go, then weld a bolt.
I'm starting to feel a little better.

ja17 · « **Reply #9 on:** July 13, 2009, 21:50:18 »

Hello Andy,

That's good news! These bolts are usually very tight, but I never heard of one breaking off during removal. Sometimes if a bolt seems stuck a good "smack" with a blunt drift and large hammer will break the "death grip" on the threads, allowing the bolt to easily be removed.

Keep us up to date!

George Des · « **Reply #10 on:** July 14, 2009, 01:13:26 »

Andy,

The suggestion Joe made to use a backward drill bit requires you to have a special reverse twist bit. Simply reversing the direction of a normal twist bit will not have the desired effect of backing out the stud. You must use the left hand twist bit with the drill switched on to reverse. You may also want to start this process with a smaller bit in order to make sure the reverse bit has an indentation to bite into and not wander off center.

Hope this helps

George Des

SteveK · « **Reply #11 on:** July 14, 2009, 01:43:46 »

Andy, I rebuilt an old truck that sat in a barn for 25 years a few years ago and got pretty good with the "easy-out". One concern I would have is once you start the easy-out process, I suspect it would be very difficult for your friend to weld to the top of the bolt. I suspect you can only do one or the other.

Before you work the easy-out, I would spend a few days soaking the area with a good penetrating oil like Kroil or PB Blaster. The oil will work it's way into the threads and help the removal process. Then you also need to make sure you get a high quality easy out tool, not one from Asia. It needs to come from a name tool supplier and you need to use the reccommended drill size (also very high quality) for the pilot hole. The easy-out will screw in left handed and will have a landing for a wrench to apply the force. These things work but you do need to be carefull not to apply too much force or the easy-out will also break. If it does not move, keep working the penetrating oil. (unfortunately, sometimes this stuff works in a day and sometimes it takes a week)

Good luck, I've been through what you are dealing with a number of times and you will feel great when you are successful!

Ron · « **Reply #12 on:** July 14, 2009, 04:57:48 »

Hi Andy, I'm so glad you found the bolt head. I was actually guessing as to where it would land, and jokingly implied if it were my car.... well, with my luck and my car, that's where it would be. Regardless, when I first read your subject line on message #1, I thought you had done something horrible with the block/head bolt. I had an Austin Healey once, and tightening the head bolts, I had one where it kept on moving without reaching torque spec. Yep, bad hole in block, what a horrible feeling.

So above this email, there's some good advice on those "easy" outs. I've broken a few off in the stump of the bolt, and they are then stuck. They are hardened, so you can't really drill out an easy out! Hopefully that penetration oil will work wonders.

Best of luck on the next step,

Ron

seattle_Jerry · « **Reply #13 on:** July 14, 2009, 06:35:13 »

If you are ever completely screwed, a part can be taken to a machinist and EDM'd (Electrical Discharge Machine).
Basically lightning is used to vaporize the metal utilizing a shaped carbon electrode. They can make any shape in metal using this process. Very accurate.

awolff280sl · « **Reply #14 on:** July 14, 2009, 10:38:22 »

Great to have these virtual shoulders to lean on.
After much thought, I'm going to go first with the welding a nut route first. I can then bail to the drilling it out. If I go drilling first, I may not have much of a surface to weld to. More expensive in the short run, but could be cheaper in the long run. "Mobile TIG" comes on Friday.

George Des · « **Reply #15 on:** July 14, 2009, 10:56:36 »

Andy,

I think going with the TIG solution is a good idea. The heat of the TIG will loosen the bolt due to the differing rates of expansion betwen the steel bolt and the steel block and once the nut is attached, it should be an easy job from there. I have never had much luck with easy outs and really wonder why they even call them that. I have broken off my share of them and they are a real problem to remove once that happens.

Good luck,

George Des

SteveK · « **Reply #16 on:** July 14, 2009, 10:58:29 »

Andy, with 3 days before your TIG man comes, I'd be soaking like crazy (a couple of times a night) with PB Blaster. You can get it at any auto parts store.

awolff280sl · « **Reply #17 on:** July 15, 2009, 01:23:24 »

Oh yeah, soaking like mad.

awolff280sl · « **Reply #18 on:** July 17, 2009, 22:58:53 »

Success!. My mobile TIG guy, quite a character, approached the problem like a surgeon. He uses a machine that he claims was produced for the US military to do in-field repairs, but is no longer produced. He says there are only 4 in civilian use, and he owns 3. The machine produces 500amps of current which is what produces the heat. At the same time Argon gas is injected at the weld site to displace air and prevent burning. No sparks, just an intense white light, and very precise for this kind of thing. The bolt had broken about 1mm below the level of the block, so he built up a cone of welded steel on top of the exposed shaft of the bolt. Onto this cone he placed a nut and welded it to the cone. It came out fairly easily with a socket. No collateral damage.
Car is back on the road and ready to travel. The retrieved bolt on the other hand needs to go into a safety deposit box as it is probably the most expensive bolt in existence.

waqas · « **Reply #19 on:** July 18, 2009, 00:04:19 »

Great news! Looking forward to seeing said precious bolt in person next week!

On my front, I'm about to start the car for the first time after putting back together the power steering pump and heat exchanger and heater box and radiator and custom heater bypass pipes and refurbished dash instruments and ... and ... and .............. blistered, bruised and tired fingers crossed!

jeffc280sl · « **Reply #20 on:** July 18, 2009, 00:15:41 »

Congrats Andy! Glad to hear the good news.

awolff280sl · « **Reply #21 on:** July 18, 2009, 01:37:06 »

Thanks. Waqas, are you putting the car together and then driving it to Ohio?

waqas · « **Reply #22 on:** July 18, 2009, 05:41:28 »

Quote from: awolff280sl on July 18, 2009, 01:37:06

Thanks. Waqas, are you putting the car together and then driving it to Ohio?

That's the goal, yes. Tomorrow, I finally tackle the leaky rear axle seal.... $:-\$

awolff280sl · « **Reply #23 on:** July 18, 2009, 11:16:00 »

Then good luck on your shakedown cruise.

Ron · « **Reply #24 on:** July 20, 2009, 13:57:06 »

Congratulations Andy. I've watched my local welder remove my broken bolts out the Fairmont engines and, as you describe, it takes skill.

On my engine, I've anti-seized the bolts you had trouble with, plus a few more. Thanks for exposing this issue with your problem.

Ron

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Author Topic: Major disaster - need advice (Read 15111 times)

George Des

SteveK

seattle_Jerry

George Des

SteveK

jeffc280sl