Broke bolt off in timing rail guide - PeachParts Mercedes-Benz Forum

New2MB · #1 11-20-2005, 11:51 AM

I was using the washer/bolt method to remove the upper timing chain guide and it went great for the upper pin. However, the lower pin seems to be stuck real good. I've been hitting it with PB but it hasn't helped yet.

When I first put the bolt in I stripped a few threads out of the pin so I took some washers off to get further into the pin. It worked well as the bolt went much further into the pin, however once I got to the point where I thought the pin was about to pop, the bolt broke instead. Now I've got a partially stripped pin with a bolt stuck in it.

The bolt should be easy enough to get back out since it's covered in PB but I think if I just try the same thing again with a new bolt I will break the bolt off in the pin again.

Does anyone have any ideas?

Stevo · #2 11-20-2005, 12:13 PM

That happened too me once. I was able to get a prying device inback of the pin and get it out. (pull at the same time) Now when I pull one I get WAY down in the threads and just go a little ways at a time.

New2MB · #3 11-20-2005, 03:58 PM

Quote:

Originally Posted by Stevo

That happened too me once. I was able to get a prying device inback of the pin and get it out. (pull at the same time) Now when I pull one I get WAY down in the threads and just go a little ways at a time.

Now I've got an ez out broken off in a screw that is stuck in the pin. Maybe I should just stop "working" on it for now.

How did you get a pry bar behind the pin? The pin hasn't budged at all yet.

New2MB · #4 11-20-2005, 05:41 PM

Well it looks like I'm totally screwed, there's no way I'm drilling through a hardened ez out. If anyone has any ideas please let me know before I try something stupid.

New2MB · #5 11-20-2005, 08:03 PM

So here's my idea; I'm going to drill through the back of the head and then push the pin out from behind with a punch. Whadda ya think?

Brian Carlton · #6 11-20-2005, 08:11 PM

How good are you with a torch?

I broke an easy-out in a bolt on a furnace. I thought I was toast.

Took the torch and very carefully melted and burned away the easy out.

Decided to increase the drill size until I finally reached the minor diameter of the threads. Then took the tap and rethreaded it. By some miracle it picks up the old threads. Did it three times on three different bolts.

Now, I caution you..........the furnace was cast iron...........the head is aluminum.

If you ever can get back to the threads in the pin, it might make more sense to rig up a slide hammer type puller. The screw can take quite a bit of force in tension...........probably more than the pin needs to move............but the screw can't take it in torsion.

New2MB · #7 11-20-2005, 08:40 PM

Quote:

Originally Posted by Brian Carlton

How good are you with a torch?

I broke an easy-out in a bolt on a furnace. I thought I was toast.

Took the torch and very carefully melted and burned away the easy out.

Decided to increase the drill size until I finally reached the minor diameter of the threads. Then took the tap and rethreaded it. By some miracle it picks up the old threads. Did it three times on three different bolts.

Now, I caution you..........the furnace was cast iron...........the head is aluminum.

If you ever can get back to the threads in the pin, it might make more sense to rig up a slide hammer type puller. The screw can take quite a bit of force in tension...........probably more than the pin needs to move............but the screw can't take it in torsion.

I didn't think about the force of the torsion, that's what got me.

When you say torch are you talking oxy acetylene?

It seems to me that the aluminum head would melt before the ez out did.

What do you think of the drilling through the back of the head idea?

Brian Carlton · #8 11-20-2005, 08:47 PM

Quote:

Originally Posted by New2MB

I didn't think about the force of the torsion, that's what got me.

When you say torch are you talking oxy acetylene?

It seems to me that the aluminum head would melt before the ez out did.

What do you think of the drilling through the back of the head idea?

Yes, definitely oxy-acetelyne.

I'm thinking that a very small pinpoint flame could heat the easy out without transferring enough heat through the screw and then through the pin and then into the aluminum. But, I caution you that it may also be impossible. The easy out that I had was a tapered square shape, so very little heat could transfer out the four corners.

Terrific.

New2MB · #9 11-21-2005, 10:00 PM

Quote:

Originally Posted by Brian Carlton

Yes, definitely oxy-acetelyne.

I'm thinking that a very small pinpoint flame could heat the easy out without transferring enough heat through the screw and then through the pin and then into the aluminum. But, I caution you that it may also be impossible. The easy out that I had was a tapered square shape, so very little heat could transfer out the four corners.

Terrific.

Unfortunately I'd have to pull some favors to get an oxy-acetelyne torch right now but I'll work at getting that ez-out out of there before drilling the head. Some extra cursing is probably all it will really take in the end.

blueranger · #10 11-21-2005, 10:30 PM

i am a little late to dinner but i have
changed a head before... and
the only pin i messed with was the top one..

the bottom pin was in the block and the top pin was
in the head...leave the bottom pin alone...

we are talking about the drivers side ....
if so just slide the timing chain over it and be done..

the only reason you remove the top pin is to assist in the removal
of the head.... you have the little plastic guide as the sole connection of the
head and everyone attempts not to brake the guide by pulling the
top pin... but you can leave both pins in... break the guide remove
the head and then just slide the guide back onto both pins.... as long
as the cover has been removed...

t walgamuth · #11 11-22-2005, 06:08 AM

rule is NO EASY OUTS FOR ME!!!!!!!!

they always seem to break and make things worse.

great idea, just doesnt work.

tom w

andmoon · #12 11-22-2005, 07:02 AM

I have never changed the guides on a diesel. On my 500 sel, I did the break bolt, then the easy out in the pin thing.
I was lucky it was the upper pin. I was able to tap the pin out from the inside (not a direct tap but using an adapted screwdriver)

Pete Burton · #13 11-22-2005, 08:21 AM

Quote:

Originally Posted by t walgamuth

rule is NO EASY OUTS FOR ME!!!!!!!!

they always seem to break and make things worse.

great idea, just doesnt work.

tom w

me too. Instead, I use left hand drill bits

duxthe1 · #14 11-22-2005, 01:32 PM

Similar instances have happened to me, a 10 year mb tech. The best way I get pins out that can't be pulled normally is with a mig welder. I use a nut that has a larger diameter inside than the pin outside. I hold the nut over the pin and begin welding to the pin eventually building up enough material to weld to the nut. Once welded I use whatever necessary to pull on the nut. Since there is little room for a good weld I usually have to weld 3 or 4 nuts to the pin to get it out. I think that the heat from several welds usually loosens a stuck pin eventually allowing you to pull it out.

andmoon · #15 11-22-2005, 02:34 PM

Are easy outs made from weldable metal?