My trans shifts beautifully up and down through all of the forward gears, however when it comes time to back up it seems more challenging than it should be. I end up putting considerable pressure on the shifter and wiggling it fore and aft a bit to get the shifter to go far enough left to engage reverse. Once it's there there's no problem engaging the gear but sometimes even going back to forward gears includes a "pop". Is there some sort of reverse lockout detent that's sticking or do I just need to adjust the linkages?