Are you sure you bought the correct Drive shaft. The correct part number for the EPX is 08029 and they are 90mm. I just bring this up as they are different than the nitro model which is only 87mm. The Volcano models don't use any kind of springs or o-rings in the drive cups for spacing.
Remove both front drive shafts and compare them. I'm guessing that one is shorted than the other. My guess is that you bought the 08059 shaft for the nitro model.
Last edited by john01374; 07-26-2015 at 09:53 AM.