Wednesday, February 24, 2010

VW 1500 replacement wiper arms

Not long ago I bought a pair of NOS SWF Type 3 wiper arms. They have the part number 311 955 407A, and they'll fit 1967 and earlier Type 3s. They're not the wipers my Ghia would have come with originally, though, but rather a later part that replaced the earliest design. The original 1961–66 wiper arms, part number 311 955 407, looked like this:

[image pilfered from]

The arms that replaced them have a slightly different appearance:

As far as I can tell, the 311 955 407A arms were introduced in the 1966 model year, superseding the earlier arms as replacement parts. I'm not sure what the functional difference is between these and the earlier arms; they both have the same poor design for clamping the arm to the wiper shaft: a small set screw that fights in vain to hold the wiper arm to the shaft against substantial torque. Working against the laws of physics, they would commonly strip themselves loose, especially if someone tried to run the wipers when they were frozen in place in sub-zero cold. The wiper shafts would get scored and galled to the point that the set screw could no long hold them in place securely.

In 1968 VW enlarged the wiper shafts from 5mm to 8mm, but this didn't solve the fundamental problem. Sometime in 1968–69 VW introduced a redesigned shaft/arm connection in which the arm was clamped around the shaft instead of being held by a set screw—a huge improvement. Wiper arms featuring this new clamp design were offered for earlier cars with 5mm wiper shafts too, as a "factory cure" for problematic early wipers. These clamping replacement arms were what my Ghia was fitted with when I bought it. They're fairly scarce—I guess the majority of early Type 3 owners just muddled through with their original wipers. Here are the two types of replacement arms side-by-side:

In 1970 VW finally solved the problem properly when splined wiper shafts and arms were introduced.

When I restore my Ghia I'll probably end up keeping the clamping arms it had when I bought it. They're fairly rare parts, and even though they aren't what the car was fitted with when new they were made to fit early 1500s and they're a big improvement on the original design. They're correct, if not actually "correct."

[Thanks to Russ Wolfe for his help in sorting out the complicated Type 3 wiper story.]

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