The 4L60E transmission from General Motors has been one of the most widely used automatic transmissions in a plethora of GM rear-wheel-drive cars and trucks. It was introduced in the early 1990s as an improved version of the 700R4/4L60 series. This means that, unlike its ancestor which was hydraulically controlled, this is an electronically controlled transmission.
Now, regarding the 13-vane pump: The pump of the 4L60E has undergone many design changes since its inception. Initially, some came with ten vane pumps but it was later discovered that these were prone to failure under heavy loading or high performance conditions. The design was upgraded to a thirteen vane pump configuration for better pump efficiency, flow rate and durability. For instance, these modifications were mostly seen during mid-to-late 90s though specific timeline can be rather hazy due to retrofittings and servicing on older models using thirteen vanes.
Another thing to note is that having three more vanes does not completely define what a thirteen-vane pump is all about. In essence, smoother hydraulic transitions are usually facilitated by this design such as reduction in susceptibility to cavitation and increased reliability in general. On hard working applications such as towing or when there is high-performance demand, the presence of these extra three vanes adds some degree of protection against pump failure.
On top of this visual inspection method being accurate there are other reasons why you should check your car’s 10 or 13 vane pump by eyes only and not with any diagnostic tools. However you will generally have to remove the transmission pump for this purpose which is best left up to professional’s hands if you are not well experienced in transmission work. If you are going for a rebuilt or new 4L60E then its specifications will indicate what type of a pump comes along with it otherwise ask if it doesn’t.
One other thing to consider is that there have been some different aftermarket kits coming out over the years which allow conversion from 10-vane to 13-vane pump. Often these will include improved material vanes for better durability.
In summary, while the 4L60E transitioned to a 13-vane pump design in the mid-to-late 1990s, specific model years may vary and older versions may have been upgraded. To truly say how many vanes are in a particular unit, always inspect it physically or refer to authoritative sources on how to check the vein count of any given part.