The E8/9 have the same drive as the Dash 9 and SD 45 and were all produced in similar versions in the same production runs and therefore with the same issues.
Version 2 still had 12 volt motors but isn’t noticeable without disassembly and testing. The drives for all these locomotives were built separately and all the locomotive truck assemblies were thereafter designed to fit that drive. A number of drives with different versions were installed in all locomotives and the other thing is that we really don’t know if protocols were followed exactly to the year of assembly and what locomotives had version 2 drives installed or more recent. We also don’t know the exact change over date (to 24 volt) and how many version 2 drives were left over and installed in newer locomotives, or vice versa.
Another thing is, how many drives in the change over actually had the required new 24 volt motors that were to be installed in versions 3 and on. I don’t even think Aristocraft actually knew if the Chinese factory was legitimately installing the 24 volt motors required in the change over into every unit, (at least immediately) even though they were supposed to.
How long did it go on, that’s anybody’s guess. I do know, of the 9, E8 models I’ve worked on, I have found 4 drives (2 locos) with 12 volt motors. The rest were 24. So I think it’s the same issue any way you go with these drives.
You literally have to tear them apart and test them before you really know, unless motor/s fail. Then, if the locomotive has been under heavy strain, the voltage of the motor might be the reason for the failure because most of the time these drives don’t fail.
Tonight, I tested 2 locomotives (First run BNSF 12 V & CP Rail 24 V drives) for speed and amperage and the 12 volt speed difference is so minut that it’s hardly noticeable and maybe that’s why Navin said you can run them together. The amperage draw was more on the 24 volt by only 1/16th of an amp but that didn’t seem to make much difference. The only difference that I noticed (barely) is the very tiny speed difference in each locomotive on the track. The one with the 12 volt motors took a measured 612.6 feet of track to catch up with the locomotive with the 24 volt motors after being started only 6 feet away from each other originally. I have run these 2 (version 2 and 4) together for 8 years or so in my program pulling 35 cars on average (sometimes more) without any gear damage, excessive wheel wear or motor failure so I don’t believe running the 2 together harms them in any way. If it does do any harm, it must take forever. Most people probably aren’t even aware of the version in their locomotive and probably will never have an issue.
Again, just my thoughts and observations.
Ken