bolt snapped..

[atomicrm]

Hi guys,

putting rocker arm assembly back on when disaster struck. besides the 4 bolts that go through the rocker arm assembly there are the 4 much smaller ones(not sure what they are called) but the 2 inside ones hold the tag that shows the clearance for valves. I was tightening these last 4 bolts and it seemed to be very loose going in and then all of the sudden the bolt just snapped. ordered a shinny new drill bit and easy out but now i need to find that bolt. any suggestions?

[Roscomacaw]

Are you talking about the bolts that also serve to secure the valve cover in place (double-ended)? I'm sure I could find a good one around here.

[atomicrm]

yes rosco, the double ended ones.

[atomicrm]

its a 53 232 v8 by the way

[DEEPNHOCK]

Kevin,
The bolt remnant should be able to be drilled out and an easy out used to remove the stub.
Or drilled most of the way out and re-tapped.

I wonder if the bolt hole had some oil in it when you tightened it up? (hydraulic lock)..

Hang in there... You'll get it fixed!
Jeff

[jclary]

There are few (if any) more agonizing experiences to a mechanic than a bolt snapping apart...especially in an engine during assembly! My suggestion is to make some type of cloth or paper "drape" (like doctors use during surgery) over the rest of the area that will allow you to only expose the bolt hole you will be working on. That way, you can protect the rest of the engine from metal shavings while drilling in the broken bolt. The key to success is in getting the drilled hole centered and straight. It has been my experience that 5/16 th and smaller bolts are the most difficult because the small size of the bolts makes it difficult to drill in the center.

When performing this operation on an engine, keep a small magnet handy and remove metal shavings often. Once you have the hole prepared and are ready for the "easy out," you can use a tap wrench handle or small adjustable wrench on the flats of the easy out to "set" it in the hole and begin to apply pressure to remove the bolt. I use a very small ball peen hammer to tap the easy out in place as I apply pressure to the broken bolt. Whispering a little prayer as you work, never hurts. When you feel the bolt move and begin to come out, don't forget to whisper another prayer of thanksgiving.

After getting the bolt out, check the depth of the hole and make sure that there is no debris jammed in the bottom that will prevent the bolt from seating properly. (That is one often overlooked cause for breaking bolts.) Then, chase the threads with a good clean tap, blow out the hole (this is where the "drape" is important for an exposed engine") with compressed air.

With clean threads, and a clean hole, you can coat your new bolt with a thin-film of "never seize" and torque away!

[Tom Bredehoft]

A couple of tricks are involved in removing (with an easy out) a broken screw.

Find a drill that will just fit the hole and spot the end of the broken piece with it. this will center the new drill.

I'm guessing that the broken part is threaded 5/16-18, use NO LARGER THAN 3/16 for your easy out.

Make or find a sleeve that will fit into the hole and keep the 3/16 drill centered at the opening, this will keep it concentric as you drill into the broken piece.

If you drill entirely through the broken piece, this will eliminate the hydraulic block on the end, or relieve the pressure on the end, making removal much easier.

[Da Tinman]

bet you can back it out using a pencil eraser.

most of the time the broken portion isnt tight once you remove the item that the bolt is supposed to retain.

I'd at least give it a shot before you start drilling.

[ddub]

The fun really begins when you break the easy out. "Ask me how I know."

[Roscomacaw]

Just WHERE did that bolt break? Did it break off just below the hex head, or down at (or IN) the surface of the head? If it broke off just below the head, you could remove all the other bolts associated with the rocker stands - remove the whole rocker assy - and what's left of the bolt could be turned out using pliers. As John says, your worst enemy is drill shavings. With a pre-full-flow engine, you can't afford to have shavings getting pumped thru the engine!

I'm going out to the shop awhile later to see if I can find a bolt.

[gordr]

What Rosco said. Where did it break? That's a long slender bolt. It probably broke in the threads, but one never knows. If it broke off flush, or slightly below the surface of the head, I would be inclined to use the MIG welder trick rather than the Ezy-Out. I have had better luck with it, and I would attribute that to the fact that the heat-cool cycles of the MIG welder trick help to loosen the stuck condition that caused the bolt to break in the first place. A cloth or paper drape is a good idea. If the head is not all covered with oil, you could simply tape over any holes (drain, push rod) with masking tape or duct tape, too.

Use the search function on this site to read more about the MIG welder trick. I am not going to repeat it over and over again. If you break off the Ezy-Out, it will be your only further option, anyway.

Tinman's pencil eraser suggestion is excellent, especially if the bolt broke because of hydro-lock. Given time, the trapped oil will have seeped out, and the stub will be loose.

[1954khardtop]

I used to break starter bolts on a GMC 6.2 diesel frequently, and got pretty good at getting them out. Try using a left hand drill bit. They cut counter clockwise instead of clockwise, and will often catch and unscrew the remaining bolt. At least they won't screw it in tighter.

[Roscomacaw]

However you get it out, I have a couple of free bolts for you. You just pay postage.

[atomicrm]

Appreciate all the tips guys. I will not be able to look at the motor until saturday morning as it is a quite a few miles away. What is the best way to go about taking the rocker arm assembly off? because the head screws go through the assembly should i unscrew all of the head bolts doing the pattern backwards or can i remove just the 4 head bolts that go through the rockers without messing up my seal? if need be i can pop the head all the way off since i have another head gasket but would prefer to not have to do that if possible.

Rosco i will pm my addy and ask how to pay you. appreciate it

[Roscomacaw]

Kev, your bolts left here this morning. One thing I didn't hear you mention was whether you were using a torque wrench to tighten these. Were you??? I would think you could get away with just loosening the four head bolts involved and re-torquing them after you've addressed the broken bolt. Then - if it were me - I'd run that torque wrench thru the whole tightening sequence on all the head bolts - using the same setting on the torque wrench that you used the first time. Either way - you won't mess the seal of the head gasket by loosening those four.

Edit to add that I'm sorry I didn't clean the bolts. I was in a hurry this morning, to catch the mailgal as she's here fairly early. I DID include new nuts tho. You'll like 'em!