Post by tony105 on Nov 30, 2020 16:11:49 GMT
It's often been the subject of debate - how many gears does the automatic Mini have and has this ever been subject to change?
At launch at the Motor Show in October 1964, the 848 four speed automatic Mini had a transmission gear selector gate showing the following positions R,N,1,2,3,4,D. The early Mk 1 Mini having a Cooper Style longer selector housed in a V' shaped selector unit that largely remained the same until the introduction of the Metro style square illuminated unit, around 1992.
The gear selector rod was shortened in 1969, at the time of the launch of the Mk3 Mini, but initially kept the R,N,1,2,3,4,D markings. In the early 1970's the 4' marking was deleted leaving the selector with the following configuration R,N,1,2,3,D. It's easy to see how this may have given the impression that the transmission had been a four forward speed unit but was now a three; in truth the 4 marking was deleted as it was not considered necessary. If the gears were routinely being selected manually the deletion of the 4th position actually made things simpler as if the car was travelling in fourth gear, the move to D' brought no change.
The only other change the selector encountered was a change from a chrome unit with black lettering at launch and throughout the Mk1/2 production (and early Mk3), to the later uniform black with white lettering.
The AP (Automotive Products) transmission was developed at the company's Leamington Spa Headquarters. Early development had intended to produce a three speed transmission but it was soon discovered that a four speed unit could be developed at a reasonable cost - for a while - a five speed unit was considered but eventually it was agreed to focus on the development of a four speed unit.
The unit was actually unique in being the only fully automatic transmission that was available for cars with a small engine for many years after its launch and was the subject of substantial investment for development and tooling by BMC. In many respects, the fact that the automatic transmission remained available as an option for the Mini from 1965 until 1996 (in the UK), but continued to be available to Mini's for the export market until production ceased in 2000, says a great deal about the soundness of the basic engineering design.