I needs some advice:

I am removing the lower oil pan of my '84 300D to replace the gasket. Of course, all but one Allen bolt came out nice and easy. One of the two bolts that also support the AC line would not come out. The nuts on the back of the bolt that are supposed to hold down the AC line are not even there, so it's not that.

So, of course I stripped the Allen bolt. I then decided I'd drill it out and use and extractor bit. No dice.

After some aborted attempts at backing it out by putting two nuts on the back (stripped those nuts) and slotting the head so I could get a screw driver in there (only mangled the head further) I decided the head of the bolt was a total loss and cut it off so I could get the oil pan removed and get to the top side of the bolt easier.

I've tried vise grips on the top side of the bolt. Of course I've applied liberal penetrating oil. I don't know what else to do.

Oh yeah, my last attempt with the hardened steel extractor bit sheered it off cleanly in the drilled hole so further drilling out is just about out of the question.

Please spare me all the you're-an-idiot-lines. I know. We're beyond that. Other than pulling the engine to replace the upper oil pan (something I am NOT seriously considering), I was wondering if you all had any ideas.

What I'm thinking about now is cutting the bolt flush with the upper pan mating surface and going with the home-job 18-bolt pan mod instead of the factor 19-bolt pattern. Is there any chance in hell that this won't just spew oil all over the place?

Oh, and I have until my wife gets home on Friday to have this fixed. It's her car!!!

(sigh)

Andrew

I wouldn't cut the bolt head off just yet, someone else might have better luck with it. I have used a 6" Ridgid pipe wrench on broken bolts with some luck. Also a set of 4" ignition style channel lock pliers sometimes works. If you have a dremel with a set of cheap harbour freight diamond burrs they will get through the extractor but it will be real slow, lots of time on your back. Took me an hour to remove a broken stud with broken drill in it from a VW head, but it did come out. You have my sympathies. Good luck Dan

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It's always something simple
91 300D 603.960 (from japan) 194K
92 Toyota Diesel Landcruiser HDJ81-t 116K
02 Golf TDI new head courtesy of PO
87 300D
97 BMW 525 TDS Wagon 5spd
bunch of Onan and other diesel generators

"...I wouldn't cut the bolt head off just yet..."

Too late. That happened already.

I like the diamond burr idea. Might try that.

Back to the hardware store!

I do not think the "you're-an-idiot-lines" has any thing to do with rust. When things rust they get bigger and sometimes they do not come out.

I took a look at mine and I believe you are speaking of the A/C Bracket that would have 2 Pan Screws coming up through it with Nuts.

You could do as you say and use some Sealant on the Pan Gasket and simply do without one screw.

If you have a good set of Drill bits you could drill out the Screw/Bolt slightly oversized. I forgot to check if there is room for that when I was under my car. On mine the bracket is close to the front corner on the Passanger side of the car.

The other option would be leave the old Screw/Bolt in place, install Pan and drill another hole completely through the Lower Pan, The Aluminum Lip and the A/C Bracket so you could install another Screw/Bolt and nut.
Since the above is done after the Pan is installed being lazy I would most likely just see if the Pan leaks before doing any Drilling.
I do not know how much effect the missing Screw/Bolt will have on the A/c line when it comes to Vibration. So you might want to run the Engine a have some one (In Park with the Parking Barake on) rev the Engine and see if the A/C line gets stressed or not.

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84 300D, 82 Volvo 244Gl Diesel

I've had the car for three years and never worked on the AC lines. When I went to take these allen bolts out, there were no nuts on the AC lines. I guess the vibration wasn't that bad.

This is one of the two bolts on the front right corner of the pan? Pic #3 http://www.peachparts.com/Wikka/OM617OilSepCheckValve

If there's nothing else holding the A/C bracket on, can you remove the bracket for better access to the bolt with vise grips?

A micro-pen torch for heat? More penetrating oil, a punch and hammer exactly onto the bolt, then the vise grips on exposed end?

I've got decent access to the bolt w/out the bracket removed. (And besides, it doesn't want to get out of the way easily.

I like your heat/oil/punch/vise grips idea, except I have found the vise grips to be not working well on the little bolt.

I think I am going to reassemble w/out the bolt and if there are leaks, take the earlier advise of drilling a hole next to the original and bolt/nut it together. Maybe even one on either side of the offending bolt. I like this plan. It's bold and takes total commitment.

When in doubt, drill more holes!

Anyone think this is a bad idea?

BTW- I've been trying to figure out if I need silicone seal on the gasket (probably, considering the non-traditional install method I will be attempting). I've read posts here saying definitely no, and other places saying no and definitely yes.

What's the deal? Sealant on the Gasket or no?

silicone sealant comes in so many grades, it makes it a hard question. the cheapest stuff is useless at best. MB factory sealant is the only kind i would even consider using. but you need to get that bolt out. do not try to jury rig it. if you drill the pan and the drill bit grabs the gasket and tears it, you will have ruined the gasket, and both the upper and lower oil pans. if you have an acetylene torch, you can use the tiniest tip available and heat that piece of extractor enough to take the temper out of it fairly quick. (somebody stop him quick if that pan is magnesium!!!) after that it will be easier (still a pita) to grind the bolt carefully out enough to either try another extractor, or all the way out until you can pull the old threads out of the hole. also, you get the bolt hot and it will expand a bit and loosen from the aluminum a little. i would heat the bolt before i tried an extractor. is it one of the blind holes or does it go all the way through the upper pan flange? if you take your time and do it right, the worst that will happen is you will need a helicoil. i like to drill em w/ subsequently bigger bits until i can pick the threads of the old bolt from the hole, but if you don't drill dead center it won't work. using the tiniest carbide bit, shaped kinda like a pencil point on a 1/8" shank can really help here. i have used one many times and i used to lend it to the other techs (that i trusted not to break it) for this same type of problem you have.

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1984 300TD "MAX" 303K+ still going...
fast '70 Chevelle 200k+
home built Shovelhead chopper

Great tips. Unfortunately, I don't have a torch. Might try a neighbor. But I really like the idea of taking the temper off the extractor bit.

I hear you re. drilling the lower pan/gasket/upper pan. Duly noted.

I recently had to drill through an EZ out with a masonry bit. I think they come as small as 1/16 or 1/8. Best tip after that I heard is to put the pan on and use the existing hole as a guide bushing, your hole will be right on center if your drill is the same size as the one in the pan. Once you're through the EZ out, the bolt will drill out w/ a high speed steel drill, the HF drill set worked well for me, be sure to get high speed steel (HSS). That at least will get you into helicoil territory, if you can find one for the screw size. If you have space to nut it on the other side, just drill it as a thru hole and use a longer cap screw w/ a nut on the backside. Just what I did w/ my suby when I broke a bolt on the Tstat.

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When I replaced my Turbo Drain Seals I decided to also remove the Pan as it had some dents in it from the Previous Owner using it as a Jacking Point.

I decided from the beginning that after pulled the Pan off and knocked the dent out (and that turned out well) if I thought the gasket was really bad I would make another Gasket from a roll of material I have or I would use Silicone Sealant and re-use the old Gasket.

I ended up re-using the old Gasket and using the Silicon Sealant. Use 1-1/2 tube of it bought at a 99 cent store at a cost of about $1.50

The fear that people have when using Silicone Sealant is that it will squeeze out and block of some important hole/s or a piece will break of and go some place that you do not want that piece to end up in.

So it is up to the user to decide if Silicone Sealant is good for the job that needs to be done.
Next some care need do be done when applying it especially concerning how thick of an amount you put on.

If you want it to stick to what you are using it on the surface needs to be completely free of Oil. I use Brake Cleaner to do that.
If you spray Brake Cleaner as I did on the old Paper Oil Pan Gasket (and wiped it off with a clean Rag) sit it in the sun and give it 15-20 minutes for the Brake Cleaner to evaporate.

I believe you need to give it time to cure like say 2 hours at a temp of at least 70F. Ounce it cures some it is very unlikely that a piece will break off and migrate some where.

To me an Oil Pan seems like a good place to use Silicon Sealant because that Sealant is thick enough to take care of warpage of the pan or if the gasket surface is a little buggered.

Silicone Sealant is a bad choice near Oil or Coolant passages where it could block or restrict them.

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84 300D, 82 Volvo 244Gl Diesel

Buddy of mine saw a Kenworth engine killed by silicone seal, kinda pricey!! I would use locktite flange sealant (the sticky red stuff) if anything and not too much at that. Cheers Dan

__________________
It's always something simple
91 300D 603.960 (from japan) 194K
92 Toyota Diesel Landcruiser HDJ81-t 116K
02 Golf TDI new head courtesy of PO
87 300D
97 BMW 525 TDS Wagon 5spd
bunch of Onan and other diesel generators

Recently needed to drop the lower pan on my '84 non-turbo Euro TD. Of course the local import-parts counter idiot that ordered the gasket, assured me ALL 300D pan-gaskets were the same. So naturally the gasket that arrived was for the turbo engine - not the same!
Long story short - the original gasket was intact and well stuck to the lower-pan. A bead of Ultra-Black RTV, applied sparingly towards the outer edge of the pan-gasket (to prevent chunks of RTV from oozing inside the engine) and all is well.
Happy Motoring, Mark

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DrDKW

Weld a nut on top of the broken bolt. The heat from the welding process will help loosen the bolt and then you should be able to back the bolt out.

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daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more