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Discussion Starter #1
Hey guys, I was swapping out the steering damper on my R170 this weekend and the bolt holding it onto the drag link snapped in half. It's a 35mm length bolt, and split about half way down, so I've got a bit sticking out still.


I've put some release oil all over it, but whilst I wait for that to set in I've tried:


1) Vise grips.. no luck here as the grip isn't tight enough and they slip off. Having oil on it probably doesn't help!
2) Tapping it with a hammer and punch, no movement at all
3) Drilling. This was a failure as my bits aren't strong enough and barely made a dent in the 8.8 steel bolt, or my technique is wrong. I've got some stronger ones on order, and a set of "left hand" bits too that should hopefully spin it out.


Changing the steering damper... it's a 20 min job they said, really easy they said... yeah, maybe if you don't have rust like my car does :grin:
 

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The vise grips are your best bet. Use the curved inner jaw, you will get a much better bite. Also get some heat on the mating surface, you want the bolt to be as cool as possible and the mating surface hot. Tapping with a hammer can help break any corrosion. Good luck!
 

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Discussion Starter #4
Put more penetrating spray and go with the punch and hammer, from what I can see the damper doesn't have any tread inside for the bolt, So the bolt is held by the nut and top end.

Yeah, one side is a part-threaded bolt + nut, the other is a threaded bolt which goes through the drag link. That's the one i'm haviong trouble with.

labelled 120 on this diagram: https://nemigaparts.com/cat_spares/epc/mercedes/1/fg/170449/66e/46/120/


The vise grips are your best bet. Use the curved inner jaw, you will get a much better bite. Also get some heat on the mating surface, you want the bolt to be as cool as possible and the mating surface hot. Tapping with a hammer can help break any corrosion. Good luck!

Thanks, my pair are quite small so I might try some with a longer handle for more leverage. The centre of the jaws on mine are too big so I have to grip it with the tip which doesn't help get a good hold
 

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Yeah, one side is a part-threaded bolt + nut, the other is a threaded bolt which goes through the drag link. That's the one i'm haviong trouble with.

labelled 120 on this diagram: https://nemigaparts.com/cat_spares/epc/mercedes/1/fg/170449/66e/46/120/





Thanks, my pair are quite small so I might try some with a longer handle for more leverage. The centre of the jaws on mine are too big so I have to grip it with the tip which doesn't help get a good hold

So it sounds like the nut is removable. This is a plus as you can use it to pull the broken threaded part out. Note: the parts image you show does NOT show a nut attached to bolt #120 . I also note that the MB parts catalog does not show a nut at that location. If the bolt was to be treaded into the drag link that may be part of the issue here. This should be determined before going forward.

If this is just a rust up issue I have done this 100% successfully in similar situations. Saturate the part of the bolt sticking our of the drag link and the other side where the nut is. If the nut can be removed take it off so that the pentrating oil can get down into the treaded area.

Once well saturated take a hammer and strike near the broken bolt (firm tapping here) on the drag link. As @jet_fl mentioned the hammer is to allow the pentrating oil to fully break down the rust bond. It is the vibrating that makes it work. You do not need to strike the drag link hard but enough to create vibrations that will work the penetrating oil all the way through. Hitting the drag link too long is just about right - hit a little longer.

When you think you hve hit it enough put the nut on and tighten it real tight. When the broken threaded part is loose from the drag link it will start turning with the nut. That's when you know the threaded part will come out easily. Just tap it out.

Patience with the tapping on the drag link with the hammer is the answer to this issue. It will work.
 

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If drilling it out buy a new decent quality drill bit and don't go too fast with the drill speed.
Steady pressure and a medium speed is all you need. "Speed kills"

Plus Gas is best as a release agent as mentioned above.
 

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If drilling it out buy a new decent quality drill bit and don't go too fast with the drill speed.
Steady pressure and a medium speed is all you need. "Speed kills"

Plus Gas is best as a release agent as mentioned above.

If you can get enough quality penetrating oil on it and a set of drills that will bore a hole you could try bolt extractors. They have a better mechanical connection for leverage.
 

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Hi,

Due to my location I am a self taught master of getting Seized Solid fasteners and components free.

IF you have a Welder and a Grinder (and can actually weld half decently) then read on .............

Buff the piece of sticking out Bolt to bright metal with the Grinder, now find a Nut large enough to slide over the portion of Bolt sticking out, if the Nut is electroplated then buff that off too.

Now find a 1/2" Drive 6 point (hex) Socket that fits this Nut plus a big Breaker Bar and Extension as required, lay it next to the job.

Weld the Nut to the Bolt with a big burn of Weld, all in one fell swoop, so that the Nut and Bolt is glowing cherry red.

Watch the glowing whilst grabbing the Socket and Bar, when it has turned from red to black stick the socket on count to five and undo it .......................

DO NOT try and undo it whilst it is glowing, it will just twist and snap further away from the Nut ;)

Never fails me and if done right never damages threads / castings etc :wink:

HTH, Cheers Dave
 

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Hi,

Due to my location I am a self taught master of getting Seized Solid fasteners and components free.

IF you have a Welder and a Grinder (and can actually weld half decently) then read on .............

Buff the piece of sticking out Bolt to bright metal with the Grinder, now find a Nut large enough to slide over the portion of Bolt sticking out, if the Nut is electroplated then buff that off too.

Now find a 1/2" Drive 6 point (hex) Socket that fits this Nut plus a big Breaker Bar and Extension as required, lay it next to the job.

Weld the Nut to the Bolt with a big burn of Weld, all in one fell swoop, so that the Nut and Bolt is glowing cherry red.

Watch the glowing whilst grabbing the Socket and Bar, when it has turned from red to black stick the socket on count to five and undo it .......................

DO NOT try and undo it whilst it is glowing, it will just twist and snap further away from the Nut ;)

Never fails me and if done right never damages threads / castings etc :wink:

HTH, Cheers Dave
Yeah, that is why I do too. Works great if there is any bolt still sticking out. I figured most on here don't have a welder available.


And if you already broke off a drill bit trying to drill it out, then no point trying to drill it out any more. You wan't be able to drill through the drill bit. If it is a really cheap one you might be able to do it with a carbide bit. Diamond bit is the only way to grind out a drill bit of any quality. If it is a good one sometimes you can break them up and get them out with a punch and hammer.
 

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Hi,

/\ /\ /\ Yes agreed :wink:

Drilling and Tapping is usually my last resort, I haven't had to do that in a long while ;)

I can also usually get out ones that are broken flush, by welding a large diameter washer onto the bolt / stud, and then when that is cool, I will weld the nut all the way around the washer, big burn and cherry red style ;)

Without trying to sound arrogant, and only IMHO, much experience over the years comes with the more preferable skill of not actually snapping them in the first place ;)

Heat usually gets stuff free, don't often need Oxy / Acetylene, normally a small Gas Blowtorch works a treat, a piece of Aluminium or a Plumbers Heat Proof Mat saves heat damaging components around the fastener to be freed off :wink:

HTH, Cheers Dave
 

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Discussion Starter #16
Thanks for all the tips, I'm going to have another crack at it this weekend! I'm using Halfords (Holts) release spray, but will give Plus Gas a try if it's not been effective.



I've no welder unfortunately... will take it to a mechanic for a heat blast if all else fails! My "left hand" drill bit have arrived, the theory being that if they can get a grip then the bolt should spin out. Depends how well that lubricant has broken up the rust I suppose.
 

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Hi,

If I were you I would not try the drilling, easy outs or the such like, once it's had a good soak, try the Grips or better still a set of Stillsons :wink:

A decent Mechanic with a bit of heat and Stillsons will very likely get it out quite easily, if you snap your Drill Bit he will take a lot longer, if at all possible and thus your invoice will go up.
Also by drilling it you limit the amount of Torque he can get on the bolt shank with his Stillsons etc once he's heated it, if it is drilled it will snap off sooner ;)

I think the LH Drill bit, easy outs etc is very unlikely to work, because this bolt is gonna be seized in there tight, VERY TIGHT !!

Good luck with it whatever you decide to do :wink:

HTH, Cheers Dave
 

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Do you have a grinder? My favorite method is to cut a slot through the tab and through the bolt lengthwise (parallel to the direction of the bolt)

It's my trick for stuck exhaust flange bolts.

yes... when your done you have a slot cut in your tab, but the new bolt will still thread in. In my case, I weld it shut. perhaps you know someone you can take it to that could do that when your all done?
 

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You might try a small propane torch on it and PB Blaster. Forget EZ-Outs. If you do manage to drill a hole, it'll likely break off in it. Assuming you made a hole, enlarge it with bigger drill bits. The bolt will weaken and eventually spin out, maybe! You'll probably have to replace the part it is stuck in. If you can remove it, you'll have better access to it.
 

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Discussion Starter #20
Hi guys, I'm back with an update - the bolt is out! In the end, no amount of penetrating fluid was shifting it, and despite ordering some drill bits I decided against using them as-per the advice here.


The answer all along was, as suggested by folks here was heat. I got a small propane torch and gave it a blast for a couple of minutes, and it slowly but surely started turning. A job well done - thanks all for your advice! :grin:
 
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