Looking through my parts shelves, I ran across a couple of 1967 Beetle SWF 12 Volt Wiper Motors (VW Part# 111-955-113). Not knowing if they were viable, I put them on my work bench for future testing. 1967 SWF Wiper Motors are a one-year-only part—the last with the small 5mm Eccentric Shaft and the first of the 12 Volt Motors. Thus, they are valuable to us ’67 Beetle Owners.
Finally, I got a chance to test them. While testing one, the positive wire got hot. Hummm—not good. I put that one aside with a note attached. Maybe the old Grease was so hardened that the Armature just could not turn the Gears.
The second Motor tested good. I decided to draw a Diagram, while I was at it, to remind me which connectors were for what function.
Powder coating produces a surface which is very durable and tough. Surfaces which have been powder coated also tend to look good for years. Powder coated surfaces are easily cleaned, making it especially popular for that reason.
However, there is a growing list of indications that powder coating is not the cure-all that it might appear to be.
What I am going to say here is cautionary. I do not yet have enough data that would allow me to say definitively that a person never should use powder coating on his vintage vehicle.
I have watched powder coating become increasingly popular over the years—especially with the vintage vehicle crowd. Chassis, engine tins, rims and seat frames and more. What’s not to like about a coating which protects and which looks so good!
My first indication of a problem came when a company powder coated a friend’s VW engine tins, including the crank and generator pulleys. The coating company failed to mask the shaft orifices, resulting in reduced shaft hole diameters in both pulleys. The coating had to be reamed from orifices so that the pulleys could be installed. This was not an easy task! And, it is difficult to remove the coating without doing some damage to the steel during the process.
Shortly, we noticed that fan belts were being chewed up at a rapid rate. After examination, this deterioration was found to be due to the powder coating in the Vs of both pulleys. Powder coating is not a paint—it often is described as “plastic”. Powder coatings are based on polymer resin systems. Under certain conditions, such as the chafing of the V belt in our illustration, enough friction can result to destroy the belt. In short order, my friend was replacing V belts, having to keep a keen eye to avoid getting caught with a destroyed belt. I rescued him on one occasion when he was caught out on the road at night in his Beetle.
The next time I heard about a powder coating problem was from the owner of a ’67 Beetle. Walter complained of stripped threads in the brake drums. At first he blamed the “cheap” Brazilian brake drums. But, the VW Community has been using Brazilian drums for many, many years without significant problems. Walter’s mechanic even blamed VW rims as being defective, which is unfounded, of course.
Then, it was revealed that Walter had had his rims powder coated.
An Internet search revealed a similar problem with powder-coated steel wheels on a particular model of farm machinery. The report talked about the need for metal-to-metal contact. The torquing of the securing bolts on powder coated surfaces, according to the report, “… is like using a plastic washer under the nut. Plastics creep under load and the nut will loosen”.
Walter and I discussed how he could rectify the problem with his rims. He used a Dremel tool fitted with a grinder to remove the powder coating. This allowed the lug bolt shoulders to torque against raw metal. Later, Walter wrote this: “Since we last spoke I did a more thorough job of removing the powder coating from the bolt holes using a power drill and conical grinder. This was a definite improvement over the Dremel I used first. I then took several trips of 40+ miles, each time following up with a check of the bolts with a torque wrench. So far there has been no loosening of the bolts.”
Not long following Walter’s incident, I received notice from a second person who had a wheel come completely off his 1962 Convertible Beetle. When I asked if the rims had been powder coated, the immediate and emphatic reply was “Yes”. The owner discovered that lug bolts on the other wheels also had loosened. In a follow-up message, the owner revealed that he had removed all wheels and had removed the powder coating where each lug bolt seats.
With these cases under my belt, I decided to interview a powder coating expert. The owner of the company took time to explain the process. He showed me special tape which is used to cover areas where powder coating should not be applied. He also explained that bolt holes, for example, should be plugged so that threads would not be compromised with the coating. He showed me special plugs for the purpose. He indicated that a knowledgeable powder coating company will take necessary precautions to protect areas of concern.
The same day, I spoke with a professional who owns a Volkswagen Formula V fabrication and machine shop. He told me of further concerns about the use of powder coating on vintage vehicles. Since each part which has been coated must pass through an oven during the process, certain parts, such as bearings, bushings, rubber parts, etc., must be removed in order that they not be damaged. Temperatures can reach 400 degreesF and higher, depending upon the application.
This professional told me that VW front axle beams are especially vulnerable to the heating process. He said that the bushings can loosen, resulting in the need to machine special bushings with set screws to hold them in place.
He then told me that should there be a necessary repair to a powder coated chassis, it is very difficult to remove the coating so that welding can be accomplished.
Great article, Jay. I’d have to agree, lack of care is the # 1 reason so many vintage VW fires happen. With some simple love and care, we can help keep these gems on the road for the next generation to enjoy. Keep an eye on those fuel lines! -ES
I continually receive questions and comments about Fuel Filter Placement. You will find a couple of Articles on 1967beetle.com regarding the subject.
So Beetle Owners hasten to place their Fuel Filters under the car near the back wheel or just under the Gas Tank.
And…we believe that we now are safe from an Engine Fire. Period!
This misconception is bound, sooner or later, to wreck havoc. Because we Beetle Owners become complacent.
Beetle Engine Fires generally have to do with a Lack of Maintenance. Here’s why:
Possibly the Number One contributor to an Engine Fire is:
Failure of Fuel Hose:
Installation of the incorrect Fuel Hose. The stock metal fittings in our Beetles take a 5mm Inner Diameter Fuel Hose. American fuel hose has a larger than 5mm Inner Diameter. Thus, when a clamp is installed, the American hose can become “puckered”, giving rise to the possibility of leakage.
Installation of correct Fuel Hose. The correct, stock Fuel Hose has an Inner Diameter of 5mm, which accommodates perfectly to the stock metal Fuel Lines of the Beetle. Fuel Hose should be clamped to the metal Fuel Lines, using care not to clamp so tightly that the Fuel Hose is distorted. The Clamp wants only to be firmly fixed so that the Fuel Hose cannot be pulled off the metal tubing and won’t leak.
Regular Inspection of Fuel Hose. Here’s where most of us fall short. We do not regularly inspect the Fuel System of our cars. I hope that you are keeping a Written Maintenance Record of your car. This can be kept on a computer or in a notebook stored in the glove box. No matter the method—keep a meticulous Maintenance Record.
And one of the most important items on your check list should be the Fuel System. Especially Fuel Hose in the Engine compartment and especially Fuel Hose from the Fuel Pump to the Carburetor.
Know when Fuel Hose in the Engine compartment was installed. We forget these things. What may seem to be only a year, quickly turns into 3 years or 5 years. Fuel Hose weakens due to several factors: Age, Heat, Vibration, Chafing and Ethanol.
Fuel Hose that has been in the Engine Compartment for more than a year probably should be removed and new hose installed. This is so easy that most of us can do it in a half hour’s time.
Heat is the enemy of many automotive components—but especially of rubber. The Core of the Fuel Hose is rubber. Heat hardens rubber and causes eventual failure. Vibration contributes to the demise of hardened rubber.
Often, Fuel Hose comes into contact with other parts in the Engine Compartment. Rubbing, or chaffing, can cause even good Fuel Hose to wear prematurely. Mitigate losses by routing Fuel Hose so that there is a minimum of chaffing.
Now, we come to the Hidden Enemy—Ethanol in the Gasoline. Ethanol causes most rubber products in our Beetles’ Fuel Systems to deteriorate. Unfortunately, we cannot find truly Ethanol-resistant rubber products for most of our VW applications. It is up to us to monitor our Fuel Systems in order to avoid this Unseen Predator.
Starting in 1965 VW changed the sunroof design for deluxe Beetles from a sliding ragtop design to a metal sunroof which requires a crank of a handle to open and close. Although the sunroof was smaller in overall size, it was much quieter, smoother and more secure than the older design.
As with any rebuilding project, preparation is vital for a successful rebuild. Although very difficult to find today, I was fortunate enough to have purchased just about every part necessary for the rebuild many years ago. NOS sunroof parts are just about extinct today, and if you’re lucky enough to find a part, you will pay a heavy price.
Russ Keller, a reader and good friend of 1967beetle.com sent the following information with photos to back up his studied position. His thesis called for “loading” the Z-Bar by altering the travel space at the bottom end of each Operating Rod. With the space filled, the Rods are “loaded”. They are not “waiting” for a “loading moment” when the Z-Bar will be activated.
Russ Keller says:
Because the Z-Bar was active only in harder turning as an anti-sway, it was too little too late.
On our ’67, we engaged the Z-Bar all of the time by installing a polyurethane bushing to take up the 2 inch slack prior to engagement. In this way it was always ready in play and we didn’t have the delay in rear suspension stiffness when needed. It was there right away and really improved the cornering and over-steer. Here are a few pictures we took when we installed the z-bar bushings. It was a cheap and easy improvement and the urethane came in black so it matched the look. It was a big improvement for little $$.
After a few hard test drives we experimented with the length of the test bushing.
Because we bought an extra long piece of the hollow material from McMaster-Carr, we could cut test samples. These ranged from 3 1/2″ down to 2″.
The 2″ was the pick by the drivers–my son, “VW Gary” (Gary Drennen from Gary’s Aircooled Service) and me. As I remember, since the 2″ bushing did not quite fill the space on the Operating Rod, that little bit of “slop” prevented the back (of the car) from feeling springy or bouncy. Springy is a technical term of art…..”Federnd” in the original German.”
Thank you, Russ, for sharing your experiment with us!