Engine/Transmission (1994 - 1998) Broken Head Stud

[SMorneau]

Had a head stud break here are the details:



It is a short one located between the exhaust on 5 and 6.



It shows a little corrosion as do some other short ones.



The truck as about 15-16 degrees of timing and only an 11 plate, which produces about 39 psi of boost.



Studs have been in for less than 25k, when the head was o-ringed.



The first sign was the smell of coolant followed by a waterfall on the exhaust side of the engine.



I believe the stud are made by A1



The head is ready to lift off as soon as I get another set of hands and eyes to help me out. Hopefully I will be able to get the broken stud out without too freaking much trouble.



Anyhow, anyone else break one of these things. I am wondering if I am not better off going back to cummins bolts but I seem to remember people having trouble with them as well. Maybe changing brands of studs?



Scott

 

[Woodenhead]

I'd suggest going with ARP studs, they're much stronger than factory bolts. If I recall correct you'll be in it for somewhere just over $400 for a set. You'll have to mill a notch into the rocker pedestals to accomodate the nut. I can't comment much on the A1 studs (never heard of them) but what did you torque the nuts too? Did you use a quality torque wrench, maybe even a calibrated one? I've seen some cheaper torque wrenches both under torque and over torque fasteners.

 

[SMorneau]

The studs were torqued with a brand new electronic torque wrench. My friend says the stud shows a tensile failure but there are no signs of necking.

The broken stud had enough exposed above the block to get it out with a vise grips Thats a good thing!

I have already clearanced the valve covers for the longer studs, and while I have recently acquired a bridgeport, I would rather not have to mess with the rocker pedestals.

The gasket and o-rings did not show any signs of leakage so I may just leave the wires/rings in instead of replacing them. Some searching on this site indicates that ARP head studs have done the same thing a time or two so maybe I will see if I can just get some A1 replacements for the 6 exhaust side bolts and anything else that shows any corrosion. The nuts and washers are still fine and most of the studs look like new.

While searching I ran across many post recommending head studs as an "insurance policy"; me I'm not so sure about that anymore.

anymore thought will be welcomed.

Scott

 

[Forrest Nearing]

ARP ARP ARP ARP ARP!!!l!

 

[Woodenhead]

What were they torqued too?

 

[SMorneau]

either 120 or 125 ft-lbs.

I cleaned the studs up last night and some of them have minor corrosion. I have been searching for an old thread regarding arp vs a1 that talked about corrosion but I can't find it. Anyone remember the one I'm thinking of?

 

[Woodenhead]

I think this is the link you are looking for.



https://www.turbodieselregister.com/forums/24-valve-engine-transmission-1998-5-2002/208050-has-anyone-seen.html



Nothing wrong with 125ft-lbs, that's what mine are torqued to.



Any chance you can post a pic of the failed stud. Perhaps of the fracture face? If it was in the truck for a decent period of time first then it's likely fatique fracture from many heat/thermal expansion cycles (similar to what your buddy told you). The corrosion could very well have created a stress riser on the OD of the stud which is where it may have all started from. None the less it shouldn't have failed like this, you'd think these studs would have a decent black oxide coating or something to prevent corrosion.

 

[SMorneau]

I will post some pics tomorrow if my camera will work.



I noticed the break surface of the part that was in the block was a little orange in color so and so I am guessing it could have been broke for a few days. I saw no signs the o-ring/gasket ring being compromised so I guess that was doing pretty well.



After searching a talking to many people it is obvious that there are a lot of studs of all brands breaking on people. More that bolts? Maybe maybe not, but the studs are certainly not proven to be the upgrade i thought they would be.



Maybe I will have to think about going to the more expensive 625 stud. :{:{

 

[SMorneau]

When it rains, it pours. The wife if now in the middle of nowhere with a gauge on her Dodge that say no oil pressure. It just never stops. I will try and post some pics later.

 

[SMorneau]

Here is the broken stud along lying on another similar stud that has typical corrosion, already washed off in the parts washer. The scratch on the surface of the one end is from me scratching it to see if it was going to be hard to drill; which wasn't necessary anyway.



Side note: The Dakota was driven another couple of hours and a local garage at her destination put a mechanical gauge on it and saw no pressure:{

It had just been in for service, the intake manifold bottom gasket, and the shop advised her over the phone it was probably just a gauge issue or pinched wire so go ahead with her trip and have it checked out when she got there. The shop that did the service seems to be a very good shop with a great reputation... they are going to make the 2 hundred mile trip to her location drop a loaner and trailer her dodge back to figure out what is happening. At this point I don't know what is going on but I am very impressed with this shop's attitude.

 

[HoleshotHolset]

Holy smokes, Scott. That's unreal... like was already said: When it rains, it floods!



I think it's high time that Dakota left your stable (cash for clunkers)... or just convert the thing to Cummins power. It's still a nice truck... just has one heck of a weak powerplant. If you go the conversion route... I have an engine and I'd help out.



Beers (Michelob Golden Light, of course... ),



Matt

 

[SMorneau]

Cash for clunkers is an option. If so I will strip it really well before it hits the lot. Too bad though is has almost zero rust and, as you pointed out, a frame.

The weak power doesn't bother the wife.

 

[Woodenhead]

No brilliant revelations here but for the record...

I think it's pretty safe to say corrosion was the root cause of that failure. Obviously when significant corrosion starts it creates a stress riser (or concentration) and can initiate the start of a crack. As the stud goes through stress cycles from thermal expansion of the head and combustion pressures the crack starts to propagate (fatique cracking). The crack continues to propagate until the cross section of the stud is reduced to the point that it breaks.



It seams bizzare to me that the stud would be that corroded. Now I'm wondering what mine look like after almost 2 years but not many miles.

 

[SMorneau]

I am not going to disagree but I will toss these thoughts out for comment.

1) any failure in tension is going to initiate at a stress riser. Corrosion, surface finish, and internal defects are all possible stress risers.

2) These studs were in the vehicle for about two years. The engine was never washed, driven in winter once, and stored almost exclusively in a heated shop. So if this failure was caused by corrosion that was due to something in the manufacturing process and/or subsequent installation/handling and/or the service they were exposed to in the truck, Then HANG ON CAUSE THERE ARE GOING TO BE A LOT OF FAILURES!

3) The stock bolts showed about the same amount of corrosion when removed at about 270k miles.

When I get the new ARP studs they will not be touched by my hands and I will use a heat gun to dry up any potential moisture before the head is installed. I will make sure the studs all have a nice smear of arp lube on the entire surface and I will torque them very carefully with my new electronic torque wrench.

Any other thoughts or suggestions will be appreciated. Frankly this whole deal sucks. Between this totally unexpected failure and what I think is coming for emission hassles I think the aftermarket is not going to get any of my money for power upgrades. That said, I still like this truck and I will still target reliability as my #1 goal (that was the idea behind the studs). With all the fixes it brakes better, steers better, rides better, got 20. 4 mpg last time I took a interstate trip, and let's not forget I can actually work on it without too much hassle.

Scott

 

[Woodenhead]

I am not going to disagree but I will toss these thoughts out for comment.



1) any failure in tension is going to initiate at a stress riser. Corrosion, surface finish, and internal defects are all possible stress risers.



2) These studs were in the vehicle for about two years. The engine was never washed, driven in winter once, and stored almost exclusively in a heated shop. So if this failure was caused by corrosion that was due to something in the manufacturing process and/or subsequent installation/handling and/or the service they were exposed to in the truck, Then HANG ON CAUSE THERE ARE GOING TO BE A LOT OF FAILURES!



3) The stock bolts showed about the same amount of corrosion when removed at about 270k miles.



When I get the new ARP studs they will not be touched by my hands and I will use a heat gun to dry up any potential moisture before the head is installed. I will make sure the studs all have a nice smear of arp lube on the entire surface and I will torque them very carefully with my new electronic torque wrench.



Any other thoughts or suggestions will be appreciated. Frankly this whole deal sucks. Between this totally unexpected failure and what I think is coming for emission hassles I think the aftermarket is not going to get any of my money for power upgrades. That said, I still like this truck and I will still target reliability as my #1 goal (that was the idea behind the studs). With all the fixes it brakes better, steers better, rides better, got 20. 4 mpg last time I took a interstate trip, and let's not forget I can actually work on it without too much hassle.



Scott

I agree. However read this from over at NWBombers. ARP head bolts ????? - BOMBER Board



Here's the initial post.



Howdy all long time no post lol. . I had a great experience with my truck as of a few weeks ago. I had 2 yep 2 broken headstuds on my motor. Aperently if you dont back them off a thread or so when putting them in when you go to torque the head down the stud will turn a bit and put added psi on the the thread hole and crack the underside of the hole and allow coolant into the thread hole and weakin the the bolt and blow the the darn bolt out into the hood causing a nice geyser of coolant and f... ing up the gasket and driving me to break my back replaceing the bolts and gasket so if your gona do this job the first time apply pipe dope to the the threads and and back the studs off a thread or two. Lesson learened. . ARP does not tell you to do this and I hope I get some cash back from them but as we all know prob not...



Mike

 

[SMorneau]

What is the preferred thread sealant?

Every stud except the long ones have corrosion to some degree. I think I can safely assume all those holes are not cracked into the water jacket.

 

[HoleshotHolset]

If it were my engine, I'd be using Loctite 565. It's really good stuff.



Beers,



Matt

 

[SMorneau]

I have thought about this a little more. Since almost all the studs are showing corrosion I have to wonder how and when the moisture got into the cavities where the studs live.



Is the gasket suppose to seal those cavities?



Did the O-ring protrusion help the comb chamber seal at the expense of the sealing of those cavities? Could use some guru input on this thought.



I also noticed some of the ultra-copper sealer used to hold the turbo flange gasket on during assembly was still pliable and in good condition. I used the same sealer on the intake horn bolt and those bolts have a nice coating of the sealant on them that seems to protect them quite well. Do you see where this is going?



Why not coat the studs with some ultra copper sealant so the moisture in the cavities, assuming I can't figure out a way to stop it, won't cause the corrosion. The ultra copper is rated to 700 deg F intermittent? Most of the corrosion is on the lower half of the stud so I could coat the bottom threads and center section up to just below where the washer will land.



I know the directions are to install the stud in the block with ARP lube but since the torqueing is done on the nut end of the stud I see no reason this would not work.



Comments Please.



Also, Who has examined studs after use and what did you observe? Any Corrosion?



Scott