Re: why use an angle drive

["David Swingle" <dswingle@xxxx>]

You are correct, they did not especially want to snake a speedometer 
cable all the way from the back of the car. There is a location for a 
mechanical speedo take-off on the manual transmission, but it is in 
the area of the ring gear. Since the ring gear was flipped over in 
the transition from front to rear drive application, the back side of 
the ring gear is up against the take-off point. Therefore, the pick-
up point is plugged in the DMC application. I've never looked at an 
automatic, but I'd bet that it doesn't even have the pickup point 
since it was a more "custom" transmission than the manual.

As an aside, BMW has been using electronic analog speedometers 
(driven by the rear differential) since the mid-80s. Perhaps there 
is an idea for a creative car-crafter - use a BMW electronic pickup 
somewhere in differential area, and electronic speedo to get rid of 
the mechanical stuff once and for all. Another project that would 
undoubtedly cost all out of proportion to the net worth. 

Another interesting tidbit (sorry, I HAVE spent way too much time 
thinking about DMC speedometers) the Lucas speedo angle drive on an 
MGB is identical to the DMC drive (from outward appearance) but lacks 
the flexible input shaft since in an MGB it hangs on the 
transmission. Interestingly enough, it costs about the same from an 
MGB parts supplier as the DMC folks charge. A lot. 

Dave Swingle

> Mike Loasby answered that one at Eurofest. I can't quite recall... 
I think it 
> was partly cable length to the rear plus no take off hub on the 
tranny. And 
> the fact that electronic speedos weren't available then. Anybody 
remember 
> that in better detail?