Caught the black death. Looking for advice.

[surlyoldbill]

My opposition and caution has more to do with the removal of the other 4 bolts and injectors. Now that the engine cannot be run, there are not effective ways to heat it in a way to remove the bolts/injectors. And even then, the risk of snapping another bolt is there. I would try to remove the broken bolt by itself before taking off the head/cam cover.

Since I've never done that, it seems to me that the head/cam cover could be removed with the injectors in place, if the hold down bolts thread in to the head/cam cover and not the block below. If that is true, maybe it WOULD be easier and safer to remove the head/cam cover with the injectors installed to get at the broken bolt.

 

[Mortarsprayer]

Well,
You are not alone on this path. Over the weekend I jump started my truck with the silver shorty. With the hood up I cold hear a slight pst pst pst. Turned out it was the #1 injector and the very beginning of black death. My picture would look exactly like the first one in this thread.

Hopefully we will have better luck with the bolts than you did.

Can you recommend the UK seller with OEM bolts and seals?

Thank you,
Nolan

PS:
What does FFR stand for? Did you have a Factory five Cobra?

 

[312d]

the cam cover cannot be removed with the injectors in place, i had a broken cam cover and all injectors had to come out, fitted new gasketS (5 in my case 6 in yours). if the cam cover if it is not bent, distorted or broken can be absolutely reusable.

 

[lindenengineering]

Guys
I have been reading this thread.
Wow talk about a job going sideways.
First drilling out the broken bolt stem is very difficult without special guides & tools etc
You run the risk of puncturing the water jacket.

Yes a mentioned helicoil isn't too effective besides have you tried to get a 6x1mm insert that has the required length to take the torque of the bolt off the shelf?

OK!
Broken off in the head is one thing, most likely the threads are intact and usable with the bolt removed, that means spark eroding it out.
In short its head off for that job if you want reliability in service!

Now, if the thread has been ripped out then an insert can be put in there with the head engine insitu. Care is needed and a long tap drill and thread tap is required due to the depth involved.
I use a special socket from Snap On to hold the thread tap because it can easily snap off due to its length. Use kerosene (paraffin) as a cutting lube.
The back hold down bolt is difficult to do due to lack of access with any regular drill, so I revert to an air angle drill--"trying task" is the operative word!

For me the most effective way to recover the job once it has progressed to
"WTF-- waddah we do now" syndrome is to CAREFULLY bore out the whole lot to the original thread depth.
The parent hole is exactly the same size as a 7/16th UNC cutting size, so bore a thread all the way down into the hole.--yes 7/16th UNC
Now get a machinist to part off some 7/16ths threaded bar (thread stock) one inch (25mm) long and bore /thread the centre 6x1 mm. Now you have a perfect insert that will hold the bolt once you have cut a screwdriver slot in the end for placement. Blow the whole clean with shop air pre-lube and install by hand .
I have had some made up in SS and having a hex end for ease of install. Made in India 'cos i couldn't fin anyone in the US to tackle this machining exercise.
This methodology works the best and its my remedy for this repair exercise which can present some challenges and often results in lots of green clams exchanging hands to fix.
Dennis

 

[woodyt30]

FFR5445, Can you tell me how many miles are on your Tin, just for my own info ? Thanks

 

[220629]

...
The parent hole is exactly the same size as a 7/16th UNC cutting size, so bore a thread all the way down into the hole.--yes 7/16th UNC
Now get a machinist to part off some 7/16ths threaded bar (thread stock) one inch (25mm) long and bore /thread the centre 6x1 mm. Now you have a perfect insert that will hold the bolt once you have cut a screwdriver slot in the end for placement. Blow the whole clean with shop air pre-lube and install by hand .
I have had some made up in SS and having a hex end for ease of install. Made in India 'cos i couldn't fin anyone in the US to tackle this machining exercise.
This methodology works the best and its my remedy for this repair exercise which can present some challenges and often results in lots of green clams exchanging hands to fix.
Dennis

I like the 7/16" UNC idea. My experience with fasteners in aluminum masts and other aluminum parts has me believe that a coarser thread in aluminum is better than a finer one. Eg. - 10-24 holds better than 10-32 even though there are less threads per inch.

Why not just use a 7/16 UNC ss steel bolt or all thread to drill and tap to 6x1 mm? Chuck the stock in a lathe and drill/tap. Then cut your screwdriver slot. I don't see where being more concentric than that is critical.

http://www.grainger.com/product/GRAINGER-APPROVED-18-8-Stainless-Steel-Threaded-WP168688/_/N-8k5Z1z0o3o3?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/29DH90_AS01?$smthumb$

Back to the Freightliner job.

As has been said, dis-assembly gives more assured results, but there is risk in needing to remove all the injectors. Second guessing what the business wants to do will probably not be well received or help your situation. In my opinion, if you don't agree with the repair method your only real option would be to take the vehicle to somebody else who is comfortable doing the repair differently.

vic

 

[surlyoldbill]

thanks to contributors for this learning experience.

 

[lindenengineering]

There are a number of grades of SS steel.
Cutting them presents problems by themselves due to work hardening.

Having tried an S/S bolt I reverted to a regular carbon steel rod as my first prototype. Put a stock piece in the lathe, bored and theaded it to 6 mm then parted it off.

Having got it right I tried out several grades of SS, some with success some not but in the end used an Indian company who could make the batch without grumbling about it.
That is how I got to this point in time.
Dennis

 

[220629]

Dennis,
It's a great idea if one is willing to remove the injectors and cover. It seems to have less risk than even the special tools with fancy guides. Thanks for sharing it here.

There are a number of grades of SS steel.
Cutting them presents problems by themselves due to work hardening.

Having tried an S/S bolt I reverted to a regular carbon steel rod as my first prototype. Put a stock piece in the lathe, bored and threaded it to 6 mm then parted it off.

Having got it right I tried out several grades of SS, some with success some not but in the end used an Indian company who could make the batch without grumbling about it.
That is how I got to this point in time.
Dennis

Stainless can be tough.

Mild steel would be fine except for corrosion. Too bad the torque specs don't allow for anti-seize. If you could use that the mild steel problems basically go away.

Not that anyone asked... getting an insert made for a DIY fix.

A full 6 mm thread into ss isn't as critical as it is OEM in the aluminum head. Drill a slightly over-sized tap hole in the ss insert for the 6mm hold down bolt. The tap then needs to cut less material. Additionally the chips seem to bind less. Lots of cutting oil and short turns in and out make tapping ss a bit easier. Patience will prevent galling.

Slow is not something a production shop wants to put up with, but it works for DIY or a couple custom made inserts.

vic

Added:
Of the fairly common types of ss, 303 grade annealed stainless has the best machinability.

The 18-8 ss threaded rod I suggested is basically 303 grade.

http://www.speedymetals.com/information/Material47.html

 

[EZoilburner]

Great thread guys, I have not removed the injectors on mine yet but I bought a new set last year that is waiting to go in when they first injector shows signs of wear. There is one thing that is hard for Me to accept here and that is installing the new hold down bolt dry, given the difficulty to remove them and that they are easy to snap. I have always put at least a little bit of antiseize on bolts that are exposed, weak or that can oxidize, can one just simply change the torque specs in order to use something such as antiseize or high temperature grease?

Thanks.

 

[220629]

...
can one just simply change the torque specs in order to use something such as antiseize or high temperature grease?

Thanks.

When I did my injectors by inspecting the removed bolts it was very evident where the threads engaged. I used an old bolt held to the new one and coated the new bolt down to a couple threads into clean area. My concept is that over time the anti-seize will creep down into the threads, but that a couple threads in didn't really affect the torque specs. At the very least it should help to keep moisture/corrosion/black death from migrating down into the threads.

vic

 

[surlyoldbill]

I think these bolts with their 60 inch pound plus 90 degree torque spec should not be changed, because they might snap. Putting anti seize on them would still result in reaching 60 inch pounds.

 

[FFR5445]

I got my van back on Friday and its running great once again. The dealer was good to work with. I got several updates over the phone and I'm pretty sure the tech actually ended up putting in more hours than I was charged for. They did reuse the cam cover and a few other parts so the final price came in below the original quote so I'm happy. They also got it to me in time for the big weekend so I could still take the family camping.

The bolt is so long it's very difficult to tell if it's stretching normally or breaking. I think the black death is the reason mine broke. Look back at the picture and you will see the black death on the length of it. The bolt loosened up initially but as it was coming out the gunk made it bind up. I think a better method would have been to spray the brake cleaner onto the bolt after I got it a bit loose to help dissolve it. They got my other 4 bolts out no problem even on a cold engine.

I only have 131k miles on the van which seems to be a sooner failure than most. Interesting enough, Minnesota mandated B10 back in July 2014. Is it possible my the black death may have partially been caused by biodiesel?

 

[israndy]

So, the Black Death caused the bolt to seize? The fix for the Black Death was done by the dealer? What was the total you ended up out of pocket?

Should we change the name to the "Black Expense, but you get it back in time for Memorial Day weekend"? Was always very afraid of it, what with the big RV price I paid for the Sprinter.

-Randy

 

[surlyoldbill]

Glad you got back on the road!
I always look at these expenses as being subsidized by all the other work I do myself; avoiding paying a mechanic. In the long run you're still out ahead.

 

[Mortarsprayer]

That is great news that you are rolling again! I hope the weekend went well for everyone.

We are fixing our BD in the #1 cylinder right now. So far today the stretch bolt came out fine and things are progressing OK. I did need to remove the top of the injector and use a puller. So that is a bit of a $$ setback.
I did keep track of the two microscopic balls that were inside of the injector. I will find out on Monday of www.oregonfuelinjection.com can clean, reassemble and test it for me. Otherwie I wil purchase a replacement.

Now we are focusing on getting everything clean. for the reassembly.

**Note about injector pullers. I purchased one of the cheap Chinese units from Ebay for $35- $40. Unfortunately it was a hair too small to actually fit over the Sprinter injector, even though it was advertised as being for the Sprinter. It took a few minutes on the grinder to open it up to be a nice fit. It wasn't a big deal because there was an easy solution at hand. Hopefully yours will be a better fit.

Take care,
Nolan

 

[Gabe Athouse]

Would it make sense to replace the hold down bolt with a stud and nut the retainer on instead? Then if the stud seizes into the cover, it doesn't matter because it wouldn't inhibit removal of the injector. Unless the stud itself would inhibit that removal, I don't know having never done this.

 

[surlyoldbill]

The bolt needs to flex in order to work. The tolerances change when the metal is different temps, and the flex bolt accommodates that change, sort of like a spring on a macro scale. A stud would be an excellent solution, if it worked. I wonder if there is some kind of washer that could be used under the nut that would allow the same amount of tension and recovery throughout the changing tolerances, like the flex bolt does? I think that a standard stud and nut would not work for long, just like a grade 8 bolt would also cause Black Death sooner than an OEM flex bolt.

 

[Gabe Athouse]

Oh wow I didn't realize it was doing this. Well there are very precision flexing washers called dome washers that might accomplish this but I don't know how to engineer that. Why does the bolt need to flex?

 

[sailquik]

Gabe,
Perhaps "flex bolt" is not the correct term for the injector hold down fasteners used on Sprinter engines (all of them).
The injector hold down bolt is an "engineered fastener" made from very specific materials, heat treated to a very
specific hardness, turned/machined to really close tolerances, threads rolled very specifically.
These bolts may in fact be shot peened at some point in their manufacture.
They are to be installed in a very specific manner so that all of the "engineering characteristics" that make
this fastener continue to apply the correct "hold down" pressure on the injector "claw" over the long haul
through millions of compression cycles, thousands of thermal heating and cooling cycles, at varying engine
coolant temperatures.
So, it gets torqued to a very specific value and then "stretched" some more by turning the additional specified
number of degrees, to provide the optimum long term life.
So, not really a "flex bolt" at all....just a carefully engineered fastener to hold the injector claw through all
of the compression/thermal/heating and cooling cycles it was designed to endure.
Hope this helps,
Roger