Calling Boneheaddoctor... Rocker bolt #5 broke off despite correct torque. - Page 3 - PeachParts Mercedes-Benz Forum

t walgamuth · #31 11-29-2005, 07:39 AM

on the cam chain security. its been a while but i think youcan wire the bottom of the chain below the sprocket together so that the sproket can t slip before taking it off. then i think you can unbolt the sproket and slide the cam toward the firewall then unbolt the cam towers and lift it off.

tom w

300DPETE · #32 11-29-2005, 07:41 AM

Quote:

Originally Posted by 300DPETE

A thought...

How much would it cost to replace the head gasket at a local shop? That way (correct me if I'm wrong), there would be enough access to the bolt once the head is removed to not require a machinist, and then I'd have a new head gasket, and again, not have to tow the car home or beg someone to let me spend the day putting my engine back together in there parking lot.

Bad idea? Am I visualizing this correctly? Would it not even work (i.e., is the bolt somehow interally enclosed even if you take the top off?).

Thanks,

Pete.

...and would there be anything else they should do while down there?...if this is feasible that is....?

t walgamuth · #33 11-29-2005, 07:45 AM

to remove the head. any reason to think you need a head gasket?

tom w

300DPETE · #34 11-29-2005, 08:02 AM

No, but as a side, I'd have a new one if I went this route.

I guess I'm concerned that I'll go through the machinist route, end up spending 2-4 hundred dollars (I'm guessing here) including towing or having someone come out, and then it might not work. I mean it seems like the right thing to do (go through a machinist), but if something goes wrong...or doesn't quite work....

How much would it cost to replace the head gasket?

Is this not a good direction?

Pete.

Pete Burton · #35 11-29-2005, 08:21 AM

Whatever you do, think long and hard before using an easy out. They are notorious for breaking off. I haven't used one in many, many years. This is a perfect application for a left hand drill bit. With proper care and any luck at all, that piece should screw itself right out. The hard part is probably finding an honest, confident, competent and willing guy to take that out. Relax. Work smart, not hard.

t walgamuth · #36 11-29-2005, 08:25 AM

i agree with burton.

if you can get a machinist to do it i think it should be between 50 and 100 dollars.

back to you r question, if i were taking the head off i would do a valve job and check springs valves etc for wear. i would look at the cylinders for excessive wear etc.

you dont say how many miles.

still i would only fix the problem at hand... getting the remains of the bolt out. and i wouldnt use an easy out.

tom w

300DPETE · #37 11-29-2005, 08:51 AM

It has about 148,000.

I'll try the machinist.

It's just that I've gotten to the point where my work and photography are being impacted in a major way. I've spent so much time on this since September, that I'm missing obligations. Securing the timing chain and pulling the cam shaft might seem like an easy thing to you guys, but I'm sure it will take me a huge amount of time. If I didn't have to do that, it wouldn't be thinking of taking it to a mechanic and having the head removed for access to the bolt (letting them do the work).

I've spent every weekend and many weekdays on this car since late August. I'm at the point where it is costing me much more in time than it would in paying someone to fix what needs to be fixed. I really want to have a finely tuned MB running my Frybrid kit, but I'm starting to reach the breaking point.

I'll write back when I'm feeling a bit better about this, I have to prepare for a meeting in 10 minutes (should have done it last night....but you know the story

)

New2MB · #38 11-29-2005, 10:56 AM

If you break an ez-out off in the head bolt (which you most likely will because the head bolt itself snapped and ez-out's aren't stronger than a head bolt) then you are in deep doo doo. Can you get someone to weld another bolt onto the top of the broken bolt in the head and then back it out?

If not, go with leftie drill bits, ez-out's are brittle and nearly impossible to remove once they break off in a bolt.

Might want to add some heat to the mix to ease things along.

New2MB · #39 11-29-2005, 10:58 AM

Quote:

Originally Posted by 300DPETE

It has about 148,000.

I'll try the machinist.

It's just that I've gotten to the point where my work and photography are being impacted in a major way. I've spent so much time on this since September, that I'm missing obligations. Securing the timing chain and pulling the cam shaft might seem like an easy thing to you guys, but I'm sure it will take me a huge amount of time. If I didn't have to do that, it wouldn't be thinking of taking it to a mechanic and having the head removed for access to the bolt (letting them do the work).

I've spent every weekend and many weekdays on this car since late August. I'm at the point where it is costing me much more in time than it would in paying someone to fix what needs to be fixed. I really want to have a finely tuned MB running my Frybrid kit, but I'm starting to reach the breaking point.

I'll write back when I'm feeling a bit better about this, I have to prepare for a meeting in 10 minutes (should have done it last night....but you know the story

)

You're almost there, don't give up now. Take a break

from it if it's not fun anymore.

300DPETE · #40 11-29-2005, 11:12 AM

Quote:

Originally Posted by Brian Carlton

The towers that hold the rocker arms have a very slight press fit onto the guides on the top of the head. They should be carefully tapped into position so that they are fully seated on the head before you install the bolts.

On the SD, I made the mistake of tapping them down when they were slightly out of alignment. This raised some metal inside the aluminum hole on the tower. I had to polish it out and start over.

So, be very careful to ensure that you are square before tapping the tower into place.

Once the towers are in place, the bolts just drop right in and start.

I thought mine were in alignment (the first set of two towers went on fine), but now that I think about it, I did see a small shaving of metal on the middle tower of the three tower set (of which the front and middle torqued properly and the back one near the firewall snapped before reaching torque). I hope I don't make the same mistake again, assuming that I get the broken bolt machined out, etc. first so I can proceed.

Pete.

300DPETE · #41 11-29-2005, 11:25 AM

I just contacted an auto machine shop not to far from where I live.

I'm faxing him the picture i posted and the corresponding page in the service manual (once I find it online). Their description in the yellow pages says "C&M Auto Machine Shop, Engine Rebuilding Gas & Diesel, Cylinder Head Service, Boring, Over 500 Rebuilt Cyl. Heads in Stock.

Sounds like the right place (both machinists and auto in the same place).

Pete.

boneheaddoctor · #42 11-29-2005, 11:47 AM

Quote:

Originally Posted by 300DPETE

Want to be the proud owner of a nice new bolt extractor of your choice (along with whatever other tools are necessary)? Pull this puppy and help me with the rocker arms (seeing as I'm jinxed) and its yours (in addition to additional funds for your time). I'm going to post a picture in a moment here.

I'm about a mile south of the Telegraph exit on I-495 (near the Huntington Metro Station) just outside of Alexandria, VA.

Can't do anything till this weekend.....but will be glad to lend you a hand then...Sorry for the delay...spent the morning at the doctors office.

PM me with contact info...to keep it out of public view.

In the meanwhile I will reread the thread to see what transpired since I last posted.

boneheaddoctor · #43 11-29-2005, 12:01 PM

OK..I have read everything and a lot has happened...thats going to be a tough one for us shadetree mechanics...I think its a good idea to get a machinist to do this having seen the photo. If you pull the head to do it valve job is a good idea while its at the machinist....vavle seals are smart at this time also due to age.

Get the headbolt tool and a torque angle measureing device (to properly tourqe head when reinstalling it)....I see those at times on Ebay...I own neither at this time.

If you need a hand then give me a call.

300DPETE · #44 11-29-2005, 12:06 PM

Quote:

Originally Posted by boneheaddoctor

....vavle seals are smart at this time also due to age.

The irony, is that's why I took the rocker arms off in the first place (to replace the valve seals and springs).

Thanks, BHD. I'll let you and everyone else know how it goes.

Also, when I had the springs and valve seals off, I did notice that two of the valves could be wiggled slightly (the rest were tight). A valve job would apply here. Anybody got a guestimation on prices?

Thanks,

Pete.

boneheaddoctor · #45 11-29-2005, 12:09 PM

Quote:

Originally Posted by 300DPETE

The irony, is that's why I took the rocker arms off in the first place (to replace the valve seals and springs).

Thanks, BHD. I'll let you and everyone else know how it goes.

Also, when I had the springs and valve seals off, I did notice that two of the valves could be wiggled slightly (the rest were tight). A valve job would apply here. Anybody got a guestimation on prices?

Thanks,

Pete.

Forgot about that point till you mentioned it...

I forget what they charge...last time I had a valve job done was about 4 years ago and forget what I paid....but think it was $140 labor...+ any required parts....but that was a 4 cylinder Honda head with 16 valves to do.

wiggly valves is not good....indicates you need the valve giuds for sure and maybe the valves too...labor for the guides should not be much....valve replacement won't up labor at all as they come out to be cut anyway..

you may have to redo seals again....they have a possibility of being cut when the land for the keepers passes by them removing the valves...so figure what set of seals run...the number of guides adn valves that are loose...plus the basic labor charges. have him check the others for clearance, you may need more.

at 150K I would only worry about the bottom end when anything happens to justify it. The shop I dealt with was in Manassas VA at Liberia and Euclid....but can not make any specific shop recomendations.

EDIT: This was assuming you carrying the head to machine shop....not having a shop do all of it for you....obviously that will jack up the price considerably.

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