A few of my chassis threads along side the side steps are stripped on my bug.

Whats the best way to repair? Helicoil, drill and tap a bigger bolt? Cut through the heater channel and fit a plate?

Any suggestions or past experiences.

try a tap first of all and clean the threads out and blow with compressed air

if that dont fix then helicoil will do the job

The bolts move around and don't tighten, so i assume the hole is gone. What size helicoil would i need?

You might need some rust repaired. Grind off the heads so you can gain access and assess then. If metal good, you can put o/size bolts in 1/4" (YUK), or pref a heli-coil or weld in a new nut.

Sorry mate, what do you mean by "Grind off the heads so you can gain access and assess then"

I don't believe there is any rust, car is extremely clean, but i guess you never know. It was a pan off restoration, i'm more inclined to think that some stripped them by over tightening (judging by the rest of the car, its pretty clean.)

What will the oversize bolts do? Will they channel their on thread, or do you mean drill and tap to 1/4' (YUK???)

Cheers

Sorry i was thinking M6 running board bolts when I said 1/4".
If the body-chassis perimeter bolts are turning, the best way to remove is still grid off the head of the bolt and what ever part of the shank you can. From there you need to remove the offending stud (probably still stuck in the nut part of the body), by maybe driving it in with a pin punch or drilling it out, niether much fun, then cleaning up the thread with a tap (M8 x 1.25). If not enough steel for the thread you may need to go up to 3/8W" (still yuk as nonmetric) Before you try any of the above, Try pulling out with a claw hammer (like your removing a nail) WHILE turning bolt with a socket. It may grab some old thread and then start coming out.

Good luck

To be honest, i haven't tried pulling them out yet, i don't think their stuck, i believe they'll come out quite easy. Saying this is so, i can drill and tap a bigger hole (as i think their wont be enough bite on the original thread to re-use the same size bolt) and therefore use a bigger bolt. Will i need to prepare the bolt at all?? i believe the stocks ones have a tapper at the end (not sure what thats for)

The bolts strip usually due to the threads getting rusty inside the heater channel (nice moist environment especially if no heater connected). Any M8 the right length will do. The point on og bolts is to pierce the chassis-body seal, you will have a hole already.

arh, cool, makes sense about the tapper. So if the existing thread will not fit the M8 bolt, drill and tap to 3/8W and use the relevant bolts for that.

Cheers Matt, will see how i go.

Hi

If the door opening is above the stripped thread, you could bore a hole in the top of the heater channel and put a nut in from the top, the hole would only need to be small, just enough for 3/8 socket to get in.

Steve

I was hoping this thread was going to go the way of welding in new captive nuts. Not because it's the best solution, but I'd love to know how to do it properly.

Hi Mick

I have a Wurth thread insert tool, I think that your close to me, I'm in Lugarno, I can come around if you want and fit some. The hole will need to be bored out a little, to about 10mm I think and the insert is like pop rivet with threaded hole in the middle and it sits proud from the hole about a 1 mm. Call me 0439 133 354

Steve

Fantastic, ill give you a buzz. Im in Allawah, so round the corner.

I prefer to weld in captive nuts, if the Wurth inserts are anything like nutserts which are very susceptable to spinning free, and then you got the same problem all over again, but with a larger hole in the panel.

Steve take a pic of the Wurth tool for us please.
(VR used to be Qld's biggest Wurth account, I must look up a local rep!)

Hi

This is the Wurth tool, I've had no problems with the inserts spinning as long as the thread on the bolt that goes in is in good condition. I cant see any other option with the body on the pan.

Steve