The WSM doesn't give any hint of how to line up the splines. It only states things like, "When reassembling coat the halves with sealant xxx and torque bolts to guy. However you should only need to line the clutch and engine output splines as you put it in place as you should have the front drive shaft removed. That does mean need to rotate the engine a bit as you slide it together. I got a call today my tractor is ready for pickup tomorrow so I will ask the mechanic who did mine. That is his second seal replacement in 2 weeks as I had to wait until he finished a similar, but lower horsepower model, before he could do mine. Dealer service manager said he wouldn't lie to me - replacing that seal is not unusual so the mechanic they have working on them gets a lot of practice.