Hi everyone,

Wow, my first Rally Anarchy post. This board is a great source of tips and ideas for my Mk2 Golf rally car project. Thanks everyone!

While re-installing the front subframe, I cross-threaded the left rear front subframe bolt.

How should I repair this: the Bentley manual way (drill through captive nut, tap new thread, install new, longer bolt) or cut open the floor and weld in a new captive nut? Are these still available from the dealer? What would be an acceptable substitute if not?

I just fear messing up the Bentley manual repair method by drilling/tapping crooked and then I'm welding in a new nut anyway... Any tips on not messing this up?

Also, for drilling/tapping, what would be the best type of drill bit and who makes a good tap for making new threads?

Thanks,
Chris

Do a search for bobbins. There's a thread here somewhere.

Drilling and tapping means that you'll be mounting the subframe in a very short thread.... and it's not too strong to begin with...

So cut the floor open - but don't install a new captive nut - but a bobbin as Dave mentions.

Make it tall enough so that you can weld it to both the bottom of the channel, as well as weld it at the top to the floor. Hope it makes sense...

If you wanna go really ballistic, make a bracket so it will be double shear...

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Brgrds
Brian

what's the thread? I may have already a nice solution.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Boy, you really did it. That is a tough fix which requires you to cut out part of the floor. Be advised that those bolts like to back out, and you need to glue them with blue Loctite, and whatever you do, don't cross thread them (Yeah, I know, hindsight is 20/20).

Also, with VWs, you have to glue the brake caliper brackets and calipers with blue Loctite as well. Don't ask me how I know.

What the f is a bobbin? I saw the thread, but I never saw a picture or what they attach to.

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"Talk about drugs. Driving a car like that, going that fast, it’s like all the drugs at once." - Tommy Byrne

"Now, Pinky, if by any chance you are captured during this mission, remember you are Gunther Heindriksen from Appenzell. You moved to Grindelwald to drive the cog train to Murren. Can you repeat that?" - The Brain

A bobbin is a threaded tube that goes from the bottom of the car to the top sheet metal in the foot well. The bobbin typically is slightly flared at the bottom to weld to the underside of the car and then tapped for the first inch or so, then drilled a bit wider then the tap above and then welded to the foot well sheet metal.

I recall they are M12 or M10's with a fine thread such as 1.5 or 2per mm

So in short I would cut it out and replace with a bobbin, I would take some measurements to locate it in exactly the same place as current.

For extra credit, I sheared off a few of these bolts after I installed the bobbins, so I wonder if there is a way to add a underside guide so the bolt is not cantilevered, a tab that runs under the sub frame and then back to the body on the car somewhere? It would also be easy just up-size the bolt 2mm when building the bobbin.

I also used rear solid spherical bearings as I tore the stock ones up in a few stages in the A-arm here. This adds a lot of shock load to the rear sub frame bolt, could be why I broke a few off.

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In the long run reality always wins.

http://forums.nasioc.com/forums/showthread.php?t=1740176&page=7

Bobbins can be seen in post #158

Apro Machining in Canada has an awesome product.

I think the thread is M12x1.25 or x1.5.

I made my own bobbin-sorta-style solution on my car (only one side so far).
I just cut the floor open, removed the old captive nut, welded my bobbin to the bottom of the channel/rail, and closed the floor again and welded it shut. Not exactly pretty - but come on... who cares... it's a rally car.

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Brgrds
Brian

Wow Dan, awesome build thread! Very inspirational.

Bobbins it is. The cage builder will put them in (yeah I know, I'm wussing out, but I'll practice on less important items ). Thanks for the suggestions everyone!

Second fawking request to OP: what's the thread size I MAY already have a simple cheap solution that is easy.

DO YOU WANT TO SPEND 10 times as much?

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

john vanlandingham Wrote:
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> Second fawking request to OP: what's the thread
> size I MAY already have a simple cheap solution
> that is easy.
>
> DO YOU WANT TO SPEND 10 times as much?

M12x1.5

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

Josh Wimpey Wrote:
-------------------------------------------------------
> M12x1.5
>


Yup their M12x1.5

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-Jason

That Subaru thread talked about seat position. On my Golf I worked with Dave Clark to get the seat located right, it always felt odd when I first sat down as it was so much lower and to the center of the car then any street car, but damn it was a wonderful driving position, by far the best I ever experienced.

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In the long run reality always wins.

Dude, you don't have to cut the floor. Peel up the sound deadening crap if it's still on there and you'll see a circular plug, pry that out. Drill up from the bottom with a 12mm bit, go get the strongest 12mm bolt you can find just long enough to go all the way up without protruding through the floor line where you pulled the plug out get two nuts and a couple large washers wrench it down tight and jam-nut it from the top then cut a circular piece of sheet metal 1" larger than the plug hole and screw it back down to cover everything up.
That's how I did mine.
I can get you pics if you need.

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easy to be hard, hard to be smart
Jv

Still interested in the bobbins as I like the idea of improving something that failed (even if it was my fault).

John V:
I haven't measured the bolt yet but what do you suggest? (going by Josh W.'s measurement)?

Kaiser's idea also sounds interesting. Easily serviceable if I mess up again Is it strong enough?

I know, I'm a noob. Thanks everyone for putting up with me!

Cheers,
Chris