Hinge pin frozen solid in bobbin

[jjbunn]

The continuing saga of the doors! I have both doors off, and a set of Banks brass replacement hinges on hand. I had to cut the old pins with a sawzall.

The problem is the passenger door hinge pin is rusted solid in the top body bobbin. I drilled and tapped a hole in it (unfortunately I messed up and didn't get the hole centred) and have a bolt in it which I hoped would allow me to break the rust, rotate the pin, and extract it.

However, it wont budge it. I'm afraid of shearing the head of the bolt off which would leave me in a worse predicament, but I've given it quite some force. I've also tried hammer blows.

In the wheel well, I removed the mud guard and can just see the top of the pin in the fender, and I've tried to spray PB Blaster at it liberally.

Any suggestions on what to try next would be most welcome!

Attached is a photo showing the situation.

[Grumblebuns]

My first thought was to drill out the old pin using successively larger drill bits but then you mentioned that the hole for the bolt was not centered ... bummer...

Another thought is to use a die grinder and start enlarging the hole until it is centered, then start drilling out the pin?

Joji Tokumoto
Fallbrook, Ca   

[jjbunn]

Hmmm ... that's a great idea! I'm not familiar with die grinders - is that something one puts in a drill? I think the hole I drilled and tapped was 5/16", so would I get a 5/16" die grinder?


Thanks!
Julian

[jbcollier]

Just get a dremel and a metal bit. 

[Roger]

Try Weasel Pee. 50/50 mix of acetone and atf. Better than most penetrating fluids.

[Grumblebuns]

Drilling out the pin procedure should probably be your last resort; you stand a good chance of buggering up the bobbin. although with the Banks hinge pin set, a slight misalignment of the bobbin hole may not matter too much.


Another thought is to use backing washers to try to pull out the pin stub. Use one or two large washers, holes bigger than 1/2" but the sized to cover the "wings" of the bobbins. Use another smaller washer under your existing bolt sized to press against the larger washers. Once all washers are aligned, start slowly cranking down on the bolt. This is probably the best way to minimize damage to the bobbin and surrounding fiberglass. With the Banks hinge pin set, a slight misalignment of the bobbin hole may not matter too much.

A die grinder is a pneumatic dremel type tool used to remove metal. You'll need an air compressor for its use.

Joji Tokumoto
Fallbrook, Ca

[jjbunn]

Update on this: I drilled the hole out a tad more, and threaded the new hole, which allowed me to use a much heftier bolt. Armed with a breaker bar, I can now get the pin to twist!  It makes a strange wailing sound when it turns - I wonder what the neighbours think?

I've now given it a liberal squirt of PB Blaster and will let it soak a day or so before proceeding.

[3929R]

Progress!

[BDA]

Those pins can be really tough to get out. I assume you're using copious amounts of penetrating oil like Kroil or Liquid Wrench. Some emery cloth or sand paper wrapped around what's left of the pin might help get enough rust off to get it out. I wish I had some trick to tell you but I think it's one of those things that just require a lot of determination.

A note about Richard's brass hinges. Unless he's changed them, they are designed to work with somewhat worn bobbins (at least that's what he told me when they didn't fit in my bobbins - my car had very few miles on it). I had to have them turned down a little to get them to fit. They are really great, though! Like everything else Richard makes.

[jjbunn]

Yes, lots of PB Blaster is being used. There is very little access to the end of the pin protruding above the bobbin in the fender - I can just about feel it. I'll update when I have more news as I realise everyone is on the edge of their seats on this one