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The text following is part of a series of articles written by John S. Henry on the restoration and maintenance of air-cooled Volkswagens. While his experience is exclusively with the Beetle, many of the techniques can be applied to other models.

This text is copyrighted and duplication, re-distribution or publication is prohibited without consent of the author.

Article: Adding lap belts to an Early Beetle
Last updated: 7/4/08

Adding lap belts to an Early Beetle

<insert painful blinking red text here>


I am not an automobile manufacturer, I do not work for the department of transportation. The modification described below carries NO warranty of effectiveness or safety.

I did this modification to my car because it had NOTHING in the way of passive restraints. These mods might not even work at all in the event of an accident. If you do something similar, don't even think about suing me if you get hurt in an accident. You do what what you want, I'll do what I want. We are both responsible for our own actions. I assume NO responsibility forthe safety or effectiveness of this modification.

Symptom- You have a pre '62 Beetle and would like to add lap belts to it.  The sunroof is very nice, but the thought of exiting the vehicle via it is unappealing.


As I said in my '57 resto Pages, I am as much of a vintage preservationist as the next guy, but when it comes to seat belts, I won't give in.  I just feel too unsafe driving a Beetle around with something around my middle to "keep the body with the car".  Yeah, I logged several hundred miles on the split sans belts, but prior to the 2001 DKF Fall Cruise, I felt the need to get something in the car.  My wife and I would probably log some 400 miles that weekend being pushed by the feeble 25 horse engine.

I opted not to go for the full scale 3 point belts this time, in the interest of simplicity and the fact that I wasn't willing to rip into the B pillars on this car just yet (plus those sill semaphores would be in the way, wouldn't they?).  I opted for the simple 2 point lap belts that Wolfsburg West sells.  They came in a nice light brown that went with my interior nicely, and were only $20 a piece.

Simple yes, but of course the anal side of me kicked in when I saw the hardware kits that came with them, and I had to go make it more complicated.  A bit.  The hardware set is a 7/16 high grade bolt and nut and big old fat fender washer.  The plan is to drill holes in the floorpans and using the washers underneath, bolt them in.  But I didn't like the big washers, I thought they would look odd, like a "bolt on", and I didn't  like the way they fit on the contours of the pan.  So I set out to design my own solution that would meet my picky tastes.

By the way, if you want to see the 3 point setup I implemented in my '57, see pages 10 and 21.

{Click on the pics below for a larger image}

Scab Plates

I favored the idea of the "scab plate" which is just plate of steel onto which a nut is welded.  The idea is the weld just keeps the nut over the hole in the plate, and does not contribute to the strain/stress performance of the overall solution.  That is, with the nut not even welded to the plate, the solution offers the same anchoring strength.  I used these plate extensively in the seat belt solution on the '57.

In this implementation, the scab plates were 3/16 mild steel with the 7/16-20 nuts (the ones that came with the Wolfsburg West belts, grade 10 or better I think) welded over 1/2" hold drilled in them.  You might notice that some of the holes are drilled off the center longitudinal line.  This is because when I made up these plates, I had already drilled the holes in the floor pans and realized that unless I made the plates off center a bit, the plate wouldn't sit neatly in the "channel" on the bottom of the pans.  You will see what I mean later on.

The edges an corners on the plates were ground and smoothed (grindstone and wire brush wheel on bench grinder) and then the faces of the plates that would contact the pan underside were sprayed with Spies-Hecker's "red-brown" etching, anticorrosive primer.

The plates were roughly 1.75" x 3.75" (44.5mm x 95mm).


Drilling the Floor

The Wolfsburg West belts came with very good instructions, on which were the locations of the mounting holes.  They should be 5.5 inches ahead of a line that connects the B pillar openings side to side on the car (I know it looks a bit skewed here).  The holes are 1/2" and I pilot drilled them first with a 1/8" bit.  This allowed me to crawl under the car first and verify the location of the pilot hole before I "committed" and drilled the larger hole.  You want the hole to be in the center of the little "channel" that is formed by the depressed area of the pan, and in the case of the inner mounts, the lip of the tunnel steel.  This insures that the plate will sit down flush with the pan when it is bolted up.

And a warning about drilling through carpet that I mentioned in one of the '57 interior installation pages.  It is very easy for a drill bit to "catch" on carpet, fabrics, padding etc., and before you can release the trigger have it de-thread a long line and ruin your precious interior.  I learned this from my days as a car stereo installer.  Two tricks.  One is reverse the drill first and spin it full speed as you bear down a little.  It will not snag, but will burn through the upholstery. 

The other trick is to heat up a nail, bolt, screwdriver, whatever of the appropriate size, to near read hot, and burn through the upholstery prior to trying to drill the metal underneath it.  Keep a fire extinguisher handy of you do this.  If you are really concerned, one you get a hole safely through the upholstery, insert a small piece of tubing or straw and place the drill bit through it to keep errant snags away.

All that being said, the German Square weave carpet in this car (the expensive stuff) showed no propensity to catching on the drill bit and unraveling.

And lastly, for those of you shuddering at the image of holes being drilled in the floor of a 1950 Sunroof Beetle, let me tell you that these are not the original pans.  They had been replaced, and actually the replacements patched over the last 51 years.  My car is very nice, and complete, but it is not perfect.  Had they been the original pans, I really don't think I would have been able to bring myself to do this.


Installing the Plates

This is what the newly drilled hole looks like from underneath, this is the inboard passenger side.  And you can see the "channel" I am talking about.  Bordered on one side by the floor "well" depression, and on the other side by the chassis tunnel bottom plate.  The area that the plate will contact has been wirebrushed and wiped with mineral spirits to remove any loose dirt or grease.  You do not wnat to take the pan down to the metal.


Here you see one of the plates installed.  The tar looking stuff you see is Eastwood's brush on undercoating (which I am convinced is simply roof tar).

You can't see it here, but on the edges of the plates which go up against the side of the channel that rolls downward to form the floor "well", the edge is ground to a rounded taper do it doesn't tend to "cut into" the floorpan and remove paint/sealer and start rust.  In this pic, the rounded edge would be the on teh backside of the plate, along the upper edge.  The edge of the plate is rounded like a quarter circle.  Make sense?

Bad picture, but you can see one of the outboard plates installed and couated with undercoating.  Here, the edge of the plate was far enough away from the depressed floor well area that rounding its edge wasn't needed.  There is ample "flat space" on the outboard sides for the 1.75" wide plates.

It was VERY difficult to flip the split on its side to take these pics.....  ;-)

Here's the finished job.   Note that the instructions on supplied by Wolfsburg West showed the inboard mounts on the lower part of the floor pan, just to the side of the "well".  In my car, that would have put the belt mount under (through?) the rubber mat.  I didn't like that idea and am not quite sure why they recommend that, unless it is that the round washer they supply wouldn't sit very well underneath.
Another shot of the completed job.  The black seat cover on the driver's seat is just so I don't mess up the upholstery getting in and out of the car while I am working on it.  This interior fabric isn't quite correct, but the light brown belts go nicely with it.  Let's hope I never have to test them out!

Copyright© 2001; John S. Henry