Truck come into shop today with 4 broken exhaust stud's on a 3406 Cat engine. Im thinking maybe this time things will go smoothly being as the last time I had to remove broken exhaust studs was a battle. Pssssf Murphy's law ... again. After opening the side of the engine up for this I pondered in my mind which method should I use... I started with drill and ez out. Drilled the first one.... hmmmm, that didn't drill to bad, but I bet its stuck in there, installed ez out put wrench on it, pop comes right out. I say to myself "you just got 25% of them out). Well if plan A worked that good let's try that again... drilled hole,, oh that was a little tougher, had to sharpen drill twice, but got nice centered hole thru stud,,, I start grinning just a bit. Install ez out, put wrench on turn pop...ez out broke off,,,&^^% in willie's best english. Don't worry Grampa I say to myself, your a pretty good welder so, just build it out a bit and weld a nut on...... put wrench on pop... comes right out,,, about this time the grin is getting a little bigger. I say Grampa your at 50% complete, its about time things go your way!!! Well eye up stud three,, Water line in the road to make plan A, drilling, out of the question,,,, so will go to plan B and weld a nut on right off... pop, nut shear's loose,,, &&^% in willie's best english. Well lets proceed to plan C.. just keep building the weld out to get a vise grips on... pop weld broke again... grrrrrrr... willie you ^%%$ole, Well lets let stud three cool a bit and move onto stud 4...weld nut,, pop,, nut shear's off.... hmmm where's this willie fella now " a mechanic isn't expensive he's priceless" or some crap like that. By this time the northern mentality is startn to take ahold... if that rebel scissorbill willie can do this day in and day out,, so can an intelligent northern...Plan D.. got out my die grinder,, a burring tool and cut the last two out... actually worked pretty good.. My question is,, anybody got any better options??
Of course, call a mechanic next time. Bah ha ha hahahahaha
I have used one of those stud removal tools, worked pretty damn good. Had about 10 bolts where the head twisted off while replacing the rollers on my D31. I was really leary about trying it, figured no way would it work, sprayed some PB Blaster on them and let it sit whilst doing other things, came back and they all came out pretty easy. Of course you need to have enough of the stud sticking up for it to grip on to. Cat dealer had the same problem on my hoe, they decided it was easier just to weld the roller to the studs on the ones that twisted off
Hey Granpa,there's nothing more frustrating.But it teaches you patience I'm currently drilling and tapping a hundred holes in bucket bosses.Third hole yesterday I snap off a 10mm spiral tap. I've got a spark eroder to get it out but I don't need the hassle
Grandpa there are no better ideas when it comes to removing broken bolts and studs, like the job you just done, no two are alike. I have used the kit that has washers, nuts and welding rods that dont stick to the threads to spin them out. Some time you win and some time you lose. Have you tried the ez out that is straight? ours is made by Rigid.
dont forget about left handed drill bits. sometimes they will turn the stud right out.
Grandpa, be sure and call a real mechanic..:tong
Lol,,, do you know one?
Nope...:beatsme
Well if you was out in the general public you would have lots of people telling you the best way.
For bolts that are broke off flush if drilling doesn't work carefully torch them out ...You wont cut cast iron with a torch .... For bolt where you can grab a hold of I slowly heat the bolt and cool it quik with some water ..The thermal shock of the bolt cooling with make it draw up .. Another trick I've used is wax ..Heat bolt and press wax into area ...This method doesn't work too good if gravity is not on your side ..
Me either. :beatsme
Lmao... I always knew you two didn't know any more than me!!!
Drilling the hole through the stud before welding a washer then a nut works well. The hole allows the stud to shrink with the heat from welding.
Have never tried a washer under the nut before.... what's that do, help you get more weld to hold?
Use a washer with a hole slightly smaller than the stud. I have a selection of fender washers. You can get more penetration compared to welding inside a nut, Then weld the nut to the washer either on the inside or outside of the nut. I save sprocket segments nut because they are a deeper nut.
For what it's worth, my usual plan, if there's enough stud sticking out, is to try the stud remover gently. Quit before the stud breaks off - you may have to ask Willie just how much torque this is. Then heat the stud cherry red and go have coffee. When you come back, chances are the stud remover will do the trick.
I can't remember the last time I saw a stud broke off high enough to get a stud extractor to hook-up.... been over a decade. And Lee thanks for the tip.... anything in stud removal arsenal is help ful.
I thought I would break every exhaust stud on the D6D.Some of the nuts were rusted all most off.Took a grinder to then.After cutting the nuts off and taking the manifold off it was a piece of cake.Just glad Murphy's Law didn't kick in.
I attacked my broken tap today.Tried Lee's idea and put a washer on then welded on a nut.I could get the tap to move and spent a lot of time gently moving it to and fro.After the 3rd nut i had to give that idea up and get out the spark eroder.It come out easy enough but took a few hours. Put a hole down through the centre of the tap and then picked the flutes out with a pick. Lucky no damage to the thread
I attacked my broken tap today.Tried Lee's idea and put a washer on then welded on a nut.I could get the tap to move and spent a lot of time gently moving it to and fro.After the 3rd nut i had to give that idea up and get out the spark eroder.It come out easy enough but took a few hours. Put a hole down through the centre of the tap and then picked the flutes out with a pick. Lucky no damage to the thread
It improves welding aim. I am a big fan of drilling first, then welding with a mig at high power. Also alot of hammering or good penetrating oil and a good nights sleep.
Cat actually sells a tool specifically for this problem. It consists of a drill jig that bolts to the head using 2 of the other manifold bolt holes. It has a drill guide bushing that is perfectly centered on the hole with the broken stud. The stud is drilled with a 5/16'' drill bit, then the remainder of the stud is cut out with a 3/8''-16 tap. The tool would be easy enough to fab up yourself. Me, I usually wind up putting an 1/8'' hole through the stud then enlarging the hole a 1/16 at a time till I get to 5/16 or start seeing threads, then break out a tap. Be sure and buy a good HSS tap, not those junk carbon steel ones that everyone (craftsman, napa, snap on) sells. I broke off too many carbon steel taps before I learned that lesson. Every now and then I'll get lucky and be able to back out a broken stud with an easy out. problem is Cat uses taperlock studs for exhaust manifolds, and they are made to bottom out in the hole, and lock in place so they dont loosen on their own, so an easy out is usually no match for them.
Yair...The washer and nut method works real good if you have access to a TIG torch. A good operator can get strengths approaching original...works real good on broken belly pan and roller bolts. I always used to soak the part in penetrating oil after it cooled a little after welding and next morning it wasn't unusual to be able to remove the stud with a twelve inch shifter. Cheers.
I used to use some snap-on LH colbolt drill and an air drill for studs all the time, worked pretty easy 80% of the time, but after using the CAT drill jig thats the way to go
Keep those tips coming... anything and everything is apprieciated.
Went to a job once on a big industrial hay press to drill some holes out for bigger bolts.The holes were 11/2 inch. I found one of the bolts had snapped on a 45 deg angle an inch down the hole.They had managed to drill it and snap an ezy out as well. I ended up being able to grind a little flat spot and drill a small hole through the bolt beside the ezy out. I got a nice clean cutting tip and got it cutting and starting at the top burnt the whole thing out and even managed to save the threads. Being in a hay factory I had I had a heap of blokes with hoses wetting down the hay in the press.
Begin to think broken stud's are like women...everyone's different!!
Life's philosophies with grandpa
heat makes stuff expand not shrink. try heating the cast around it and then spay penetrating fluid onto the broken stud to cool it and lube it.
Sorry, Lee's right when drilled the stud will actually shrink when it cools from being heated. Save your penetrant all it will do is burn off. And castings hardly move at all hot or cold. jr
I'm with jr. If you heat around a hole, and the metal expands, won't the hole get smaller? (metal expands equally in all directions, not just where you WANT it to...)
The short answer is yes and no. It has a lot to do with mass and diameter and the hole in most cases will end up being larger. Heat a motorcycle cylinder and the press fit inner liner will fall right in. Heat a casting and a press fit bearing will do the same, as a few examples. In getting broken studs out the most important thing is that "SOMETHING" is moving. Any sort of movement from heat will help break the bond/rust between the two parts. The stud will also grow longer which helps break the bond.
yes, heat will expand metal, although when it cools it will shrink to be smaller than the size it was originally (i'm sure this is what lee meant) you can heat the parent material to cause the hole to expand which will loosen the stud but once the heat has gone the hole will accually get tighter, and heating a cylinder head with an oxy is't the best thing either when you're removing a broken stud the method of removal greatly depends on the reason for the stud breaking, exhast studs generally break from expansion and contraction of the exhast shearing the stud (usally flush its the head face) which means the stud shouldnt be seized in the head, so drilling the centre of the stud out with LH drill bit and an air drill can have good results (air drill has more torque to spin the stud out) with this fails and easy out (flute type extractor) is my next choise, followed by a light oxy flame on the stud (you need to try and heat the studd without heating the head too much) lubed up with silicon spray (wont steam off like crc) if there is stud left hanging out, a decent hit with a hammer and welding a nut on or even some vice grips may work best thing to remember is to give yourself a hand before you strip and give the bolt/stud a hit before you pull something apart if you think it might be tight and work the nut/bolt back and forth to help prevent a dodgey bolt/stud breaking
in a prevous job the company i worked for had a heap of gear working in a nickle mine around the processing plant cleaning spoils from conveyors and in/around tailings dams, that was pretty hard on the gear and everything was rusted they had brand new CAT 740s, D6Rs, 330s best job i remember was rebuilding x2 final drives on a 330C we couldnt remove the cap-head bolts which held on the hydraulic motor onto the final drive so we got out the mag. drill and drilled the heads off the bolts but the motor had seized onto the shanks of the x4 M14 bolts so we stripped the final drive and had to mount it up in the press, ended up taking 55t on the press to push the hyd motor off the final drive case after it was off the x4 cap head bolts (now studs) were unscrewed by hand!
anyone got a pic of said tool set up?
You're looking for the 6V-9050 Tool Group. Here's a pic and a brief description of how it works. According to the Tool Guide it's for 3200, 3300, & 3400 engines. Not sure how it will work on the latest generation of engines or on 3500s. Also some interesting comments about not being recommended to use Helicoil inserts to repair heads with taperlock exhaust studs.
thanks Nige
Some times we heat the outside and while it is hot, remove the bolt, pin or bearing in the bore/hole. If you cant get it out though, when it cools it may be tighter. Heating a bolt, pin or bearing in a hole/bore will make it expand but because it is in a bore it can't expand so it gets really tight, but when it cools it relaxes and actually shrinks. Then it will come out. Drilling the hole in the bolt allows the heat to get all the way through and gives the bolt a place to shrink to. We use the drill jig if the welding wont get the studs out. The two cat drill bits are awesome and cut right through the hardened studs.
never heard of trying amasonary drill with a steel cutting edge on it. Got to remember that one. They got to be hard as bloody you know where.
I have used masonary on a few hardened shafts. I take the drill bit to a place that has a diamond grinding wheel, when sharp they work pretty good.
I usually carry a couple of different sized masonary drills in my toolbox.I sharpen them with a standard soft/greenstone you use for carbide. I drilled out a broken centre drill with one of these the other day http://www.artu.com/drillbits.htm They work pretty well.
I have a method that really works well to heat the stud. Drill the stud as deep as possible, I normally use an 1/8 bit. Knock the flux off a piece of welding rod, drive it into the hole. Connect your welding lead, get the ground as close as possible. Using your foot controller, slowly increase the current until the rod and the stud begin to glow. Let it cool, sometimes you can just turn the rod and back out the stud, otherwise remove the rod and use an extractor. This is a great method for tight areas and places you don't want to use an open flame. Usually it won't even disturb the surrounding area or paint.
One thing that I do on broken stud's/bolt's in area's you can't get a drill into is take an 1/8th in. drill bit and a short 3/8 bolt. Drill into the threaded in of the short bolt almost to the head. Take the drill out, reverse it, put super glue on the shank and install it into the hole on your short bolt you just drilled. Let it cure a minute or two, then get your air rachet and a socket that fit's the short bolt, use that as an angle drill. This contraption will fit into some mighty tight spot's. When done with the drill, just heat the bolt up and you can retrieve your drill bit with no harm done. Kervoo...... good method, thanks for sharing with us.
Tons of great ideas!
I have a really small tight angle drill that works well. .I have cut down a tap and pressed a nut onto it to use a ratchet to turn it. Tap sockets are good but some time too long.