What year changed from 400 to 420 mm steering wheels?

[Cornpanzer]

Was the change in 67 or after?

[Allen Henderson]

My 67 stock was 400mm. Update: March 20, 2008. I was wrong sb 420mm.

-Allen-

[gulf908]

CP,

My take is that the 420 mm wheels were from '64 to '68 MY , the 400 mm wheels were from '69 MY to '73 MY except for the Carrera 380 mm wheels.
I also suspect the 380 mm 914 wheels were an option from the 914/6 introduction date but were not well publicised as an alternative wheel on a 911 from '70 to '73.

HTH
Dennis.

[Allen Henderson]

Dennis I think is correct. I went out a measured the take-off from my '67 and it is, indeed 420mm. This puzzles me though. Because, remember, the restored horn butterfly I was to buy from you wouldn't fit a 380mm wheel-you said you tested it. Yet, the hornbutterfly that came off my 420mm wheel fits my thick grip 380mm just fine? Makes me think there was/is only one size early metal horn butterfly with button? Guess I should have bought it from you after all.

-Allen-

[Cornpanzer]

NO,
I am almost 100% sure that there was different butterflys. Remember, we measured yours an mine and there were clear differences in the pitch of the "wings".

Are you sure that your wheel is a 420? What is the part #?

[Allen Henderson]

NO,
I am almost 100% sure that there was different butterflys. Remember, we measured yours an mine and there were clear differences in the pitch of the "wings".

Are you sure that your wheel is a 420? What is the part #?

I had forgotten but now do remember we measured them. My wheel is 420mm on the outside, biggest, diameter. If I measure the center of the grip to the center of the grip, it measures 400mm. As a reference, my two 380mm 914-6 wheels measure 380mm when I go to the outside, biggest diameter. Perhaps, a 400mm (or 420mm) wheel is measured from a different spot as these are, after all, "nominal dimensions. The part number is "610" No, don't know what that part number relates to. Speaking of which, is this pic a factory option, or, did someone make this up from 356 and 911 parts? Thanks.

-Allen-

[real550A]

Sure looks to be a 356 horn button in a 911 wheel. I don't think
it's a factory combination. Could be wrong.

[Allen Henderson]

So far, the earliest I can find mention of a 400mm steering wheel is for 1970 model year.

I now have four steering wheels I measured. The '67 wheel is 420mm (nominally) outside diameter. Two extended hub wheels are 400mm OD (see photos below) a 914 wheel is 380mm OD. So we know the nominal dimension of a wheel is the OD, e.g. a 400mm wheel has an OD of 400mm; you might say well, Duh!, but I didn't know how it was measured.

I now have two early butterflies and they are both identical. One I know came from with my 420mm wheel. Both butterflies fit all three size wheels. Has anyone seen different angeled butterflies? If you look at the angle of the spokes on all three different sized wheels, it is nearly the same. At the outside end of the spokes they bend a little more or less, depending on the wheel. This is why the butterflies fit all three wheels.

Does anyone know how to read the date codes below? These are different than I'm used to and knowing it date will help determine the move to 400mm steering wheels which I think was 1968. Thanks.
-Allen-

[69S-S/R]

My 1969

My 1969 S wheel is 400mm and is dated 7 68.
Tom Scott

[ttweed]

I have a 400mm leather wheel dated 7/69 with a 901 part number which would have most likely been used in early 1970 production, no?

TT