Stripped Threads

’67 Volkswagen Beetle — Stripped Threads

Lug Bolts often are incorrectly called “nuts”. For the 1967 Beetles these bolts are 12mm X 1.50 thread with a 9mm head.

Over-tightening the lug bolts not uncommonly results in stripped drum threads. Or, perhaps it is just the years of loosening and retightening the steel bolts that eventually wears the soft cast iron threads.

Once the threads in a drum hole have been stripped, the car should not be driven. The lack of one lug bolt can bring about failure of the remaining bolts due to the undue stress placed upon them.

An obvious solution is to buy a new drum. But, as with many other Volkswagen Beetle situations, there is a good solution which will save that drum!

But, first, let’s talk about some tools which will make this job possible. If you don’t own the tools which we will discuss, or don’t want to own them, you may be able to find a shop or VW friend to do this repair for you. My VW friends and I have found it difficult to locate a shop with the proper tools to do this job.

An alternate idea would be to purchase the tools, then to take the drum and the tools to a qualified machinist to have the work done.

You will need the following:

  • 1. Drill Bit—31/64th inch
  • 2. Tap—14mm X 1.50 Thread. Use the taper or plug (or “spiral”) tap
  • 3. Die—14mm X 1.50 Thread
  • 4. Lug Bolt from a 1968 and later Beetle, Type 3 or Karmann Ghia (USA specs)
  • 5. Tap and Die Kit with the proper tools for using the Tap and the Die
  • 6. Heavy duty battery-powered or electric 3/8ths inch Drill Motor or a Drill Press
  • 7. Light oil or some other drilling-aid fluid—even WD-40
  • 8. Torque Wrench

’67 Volkswagen Beetle — Stripped Threads

Compare the 12mm lug bolt and the 14mm lug bolt—both in diameter and in length.

’67 Volkswagen Beetle — Stripped Threads

Remove the offending brake drum. Time to do a little cleaning of it, anyway. Maybe even to paint the outside so that it will resist rust better. The cast iron holds paint well. If you were in a hurry, you COULD do this job leaving the drum on the axle. This is not advisable since it leaves metal shavings in there with the brake shoes.

First you will need to drill the stripped hole to the next size. Wanting to leave as much “meat” as possible for the new threads, we are going to use a 31/64th bit. A ½ inch bit will work but will remove too much metal and can result in weak threads when the hole is tapped.

’67 Volkswagen Beetle — Stripped Threads

Drill the hole cleanly. Usually it is easy to hold the drill motor straight while drilling, but be as careful as possible to get a good, straight hole. If you have a drill press, this process will be easier.

Now, for the 14mm X 1.50 tap. Install the tap into the proper handle from your tap and die kit. Again, taking care to hold the tap straight, tap the new threads into the hole. You can use a light oil, or even WD-40, to help the process.

’67 Volkswagen Beetle — Stripped Threads

Clean the new threads well using compressed air, if you have it. If not, a small toothbrush or other device will work. Computer-cleaner canned air will work.

Use a wire wheel or some other cleaning device to thoroughly clean the threads of the 14mm lug bolt which you have selected as the replacement bolt. Rusted bolts will not torque smoothly.

Lay the wheel over the drum and install the 14mm bolt into the newly threaded hole. The bolt may protrude through the drum a bit. If so, this protrusion should be removed so that it will not bear upon any of the braking mechanism as the drum turns.

A bench grinder works well to shorten the bolt, but a hacksaw also will work. Secure the bolt head in a vise and cut to remove the tip of the bolt.

Once the excess has been removed, I like to run a die over the threads so that they will be straight. If no die is handy, use a small file to straighten the threads at the tip so that the bolt will turn into the hole smoothly.

Once you are satisfied with the bolt length, reinstall the drum onto the axle.

In the USA, the 1968 and onward, Beetles, Karmann Ghias and Type 3s have the 9mm head just as do those of the 12mm bolts for the “wide-five” drums. As a quick way to recognize the larger diameter bolt and hole, use a spot of paint or fingernail polish to mark the bolt and the hole.

With the car still on a jack stand, position the wheel and screw all 5 bolts in by hand until the beveled shoulders have seated. I use a socket at that point to tighten all of the bolts, going diagonally from bolt to bolt. Tighten until all are well secured but not yet torqued, due to being off the ground.

’67 Volkswagen Beetle — Stripped Threads

Now, we come to avoidance. Torque the 12mm lug bolts properly. Don’t use a big wrench or socket bar and stand on it! Use care and likely you won’t have a repeat performance. Lug bolts for the “wide-fives” (5-lug) ’67 rims should be hand-torqued to 72 ft/lbs. (14mm X 1.50 bolts should be torqued to 87-94 ft/lbs). The paint-dot will help you to remember which is the 14mm bolt.

Lower the wheel onto the ground and torque the bolts, going diagonally from one bolt to the other until all are properly torqued. Maybe you have a more modern torque wrench than mine!

’67 Volkswagen Beetle — Stripped Threads

And, there you have it—one salvaged 5-lug drum. Plus, you have a kit for the next stripped thread situation. If you have a close-knit VW club or group, maybe you have communal tools. In my case, I lend this tool kit to my VW friends so that they won’t have to purchase the set themselves.

I buy used lug bolts at swap meets anytime I see them. I find them to be handy for situations where I am working with a car that is missing one or more. Carry a couple of each size with you in the corner of your road tool kit and you’ll be thanking yourself when you’re down the road. Your VW friends will be thanking you too…when they become stranded and find that you have just what they need to get going again.

Special Mention: I want to thank fellow-Texan James Anderson for starting me on this journey. Presently, James is working to complete the restoration of a black 1967 Beetle.

The Finishing Touches for Your Vintage Volkswagen™

Jay Salser

I’ve been driving and working on VWs for over 37 years. In fact, I raised my family in these cars. Now, I’m 75 years old and enjoy VWs as a hobby. The ’67 Beetle always has been my favorite year.

18 Comments

Ben Haynes

about 5 months ago

Very well put together, Jay.

Reply

Jay Salser

about 5 months ago

Thanks, Ben. I hope that it helps someone down the road! jay

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Bryan

about 5 months ago

Good stuff, Jay. I haven't bought a Bug yet but I'm still pining for one. Also I'm starting ta dig Karmann Ghia's a tad. Jay, what do ya think about VW Karmann Ghia's? I saw a '69 really sported up with very cool tires and wheels for sale on the internet and it looked awesome. Dark blue and all!

Reply

Jay Salser

about 5 months ago

Hello, Bryan...Karmann Ghias are pretty scarce cars. I have a '68 Coupe, which I dearly love. But...parts are several times the cost of Beetle parts. And...get ready for rust issues. These are uni-body vehicles and most have some rust. I do not recommend a Ghia for the faint of heart. If you consider one--please look past the nice tires and wheels. Those often divert one's attention from the real issues which are going to be costly. jay

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Bryan

about 5 months ago

Jay, Thanks for the information on Karmann Ghia's. You're right, I was just looking at the attractive bodystyle and nice wheels and tires. I am somewhat mechanically inclined, not by an means a master mechanic. I kind of like doing some auto maintenace/repair on my own, just need ta learn a lot more to feel very comfortable about it. I will now go back ta just looking for a VW Bug. What about the VW Fastbacks? They seem ta be hard ta find on the net or Hemming's Motor News. What'd ya think about VW Fastback's or Squareback's. I don't like Squareback's looks nearly as much as a Bug's looks or a Fastback's looks. But what about parts and prices for them, too, if you know?

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Jay Salser

about 5 months ago

Bryan...Again...we are talking about pretty rare cars when we get into the T-3 Class of SquareBacks and FastBacks. As a result...parts usually are at premium when they can be found. I like these models but wouldn't try one at my time of life (75 years old). I'll stick with Beetles and my Ghia. So far, Beetles are more plentiful and parts more available and more reasonably priced. If you read my piece on "Restored, Original and Survivor" you can begin to appreciate the scope of the Vintage Volkswagen Hobby. Unfortunately, people are destroying VWs by modifying and cutting at a faster rate than other examples can be restored and treasured. I foresee that viable Beetles will soon join the ranks of expensive and difficult to find autos in the near future. jay

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Bryan

about 5 months ago

So if you get your Beetle now, while the 60's ones kept in pretty good shape are selling for $3,500 - $9,000, and take care of it you'll still be in good shape overall, right? Parts-wide availability and such. I know I would need ta bone up on some things to do myself as far as valve alignment, for instance, but I think I'd be all right with doing some of the things like that myself. You're not saying that old VW Bug's are going to be a tough operation ta participate in any more, are you?

Jay Salser

about 5 months ago

Bryan...I've had to concede that the cost of buying into a vintage Volkswagen is becoming more and more expensive. As you suggest, maybe it's a good idea to buy a nice car now and maintain it rather than planning to buy one later and have to spend much more for a nice car. As well, I have begun to collect some of the most critical parts. These I have found either NOS, in good condition or I have restored them. This morning, for example, I took a '67-12 Volt correct generator to have it restored. I don't want to be caught without one, especially since I have two cars which use the same generator. And so forth. Yes...I want to continue participating with other vintage VW owners. So, I have invested NOW so that I'll be guaranteed a place at the table with the rest of the VW Community. jay

Mike Buettell

about 5 months ago

Outstanding article, especially the part about using a torque wrench on the lug bolts. Don't let those monkeys at the tire stores with their air guns anywhere near your car.

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Jay Salser

about 5 months ago

Mike...you are so right about some of the tire shops. I notice that they are getting better at the larger shops. I once had the lug bolts so tightened on a Volkswagen, that I had to go to a service station to have them to loosen the bolts on all 4 wheels. Later, I asked the person who put them on so tight why. He told me that he didn't want them to come off on the road somewhere. Sigh. Yuh gotta luv it! jay

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Hendrik Blommers

about 5 months ago

I have the same torque wrench. A Sears Craftsman beam style that I bought about thirty years ago. I own a 66 beetle and a 69. I did not know that the lug nuts changed thru the years. Thanks for the informative article.

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Jay Salser

about 5 months ago

You have discovered just how old I am, Hendrik! Since this one continues to serve me well, I never saw the reason for buying a modern one. Thanks for coming to 1967Beetle.com! jay

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Tom

about 5 months ago

Great article. You cowpokes down in Texas sure know a thing or two about ingenuity. Not surprised at all. Sure appreciate the articles and the common sense approach. I have two torque wrenches one in metric and the other in useful!!! (and a clicker for backup!)

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Jay Salser

about 5 months ago

Howdy, Thomas! How are y'all way up thar? I just never was into wrench pulling enough to warrant getting any tools past "useful". Thanks for staying tuned to 1967Beetle.com. And, keep ridin' them roads in that thar '67 Bug! jay

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Bill

about 5 months ago

Nicely written article though I'm feeling a bit guilty in that I just put my 69 bug wheels on with a 1/2" impact! I hate being in a hurry! lol

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Jay Salser

about 5 months ago

Ah, Bill...I know the feeling. It's called "the tyranny of the urgent!" Or perhaps it's know as "human nature"? May all your torque-ings be benign! LOL Thanks for being a Reader of 1967Beetle.com! jay

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Bryan

about 5 months ago

Just remember, ya don't have ta break the handle off yer torque wrench in order ta make sure yer lug nuts are properly fastened down. Right?

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Jay Salser

about 5 months ago

Right! I will be careful! LOL jay

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