A500 planetary set changed at the factory in 1996. Used from 1996 to 2004(15 degree upgrade).
A518 planetary set changed at the factory in 1994. Used from 1994 - on (15 degree upgrade).
The planetary set is the same for both the A500 and the A518.
As I mentioned in a previous post on this subject, the Factory made the change as the 15 degree planetary is stronger than the 22.5 gear set.
The friction plates in the overdrive section, are the same, no matter if its off a A500 or A518. The A518 could have 3-5 Overdrive frictions and 8-10 Overdrive direct frictions. The A500 could use 2-4 Overdrive frictions, and 5-8 Overdrive direct frictions.
