I would not remove the motor again, unless you really need to. On the balancer damper, listen for noise coming from the left front of the engine, just forward of the footpegs. When the rubber dampers start to come apart, they allow the metal balancer to wobble, and there is very little room between the balancer and the case, so the steel gear teeth on the balancer will start to dig into the aluminum case. Aside from noise, another way to check for deterioration of the rubber damper is to check the screen behind the oil drain plug on the bottom left side of the engine. This is where the oil should be drained, not the plug on the bottom of the engine. Look for small particles of rubber or aluminum in the oil screen.
If you have any doubts about the cam chain tensioners, or if you do the "grambo trick", and it quiets the noise down, but it comes back fairly soon, I recommend replacing the automatic tensioners with the manual ones. I messed up the first time, and replaced them with new Kawasaki parts, which failed again after about 10,000 miles, next time I went with the manual ones from TOC, no noise since. Everybody seems to have a different way of replacing/adjusting the manual tensioners, I posted my method here somewhere, I'll dig it up if you decide to go with manual tensioners.
As for the splines, it's not really that hard. You do not have to remove the front bevel gear assembly, and you do not have to remove the swing arm, which is quite a job in itself. While the manual calls for lubing the swing arm bearings, I don't recommend it. The amount of work it takes to do it just isn't worth it. You can check for excessive play in the swing arm bearings when you do the spline lube, and if you do find a problem, you can remove the swing arm, and replace the bearings with new ones. Unlike the splines, worn swing arm bearings won't really do any damage. I have 43,000 miles on my '02, and the swing arm has never been off. The bearings are still fine.
To do the spline lube, you do need to remove the rear wheel, both shocks, and the final drive gear case. When you get the gear case off, the rear splines are right there. The male part is sticking out of the gear case, the female part is inside the end of the driveshaft. I just coat the splines on the gearcase with grease, then fill the end of the driveshaft with grease, and push them back together. That will squeeze most of the grease out of the driveshaft, and make sure everything is well packed with grease.
As for the front, I do that first, before the rear. With the swingarm down as far as it will go, I pull on the rear end of the drive shaft, which will disengage it from the front bevel gear assembly (you have to pull back the rubber boot to get to it) Then I use something small, like a popsicle stick, to pack the front end of the driveshaft with grease, and coat the splines on the front bevel gear. The trick is getting the driveshaft to engage the splines on the front bevel gear, because the U joint will try to drop down. I've been able to do it fairly easily by using a long skinny straight screwdriver in my left hand at the front coupler to help hold the U jount up, and wiggling the other end of the driveshaft around with my right hand. When it lines up right, it will slip right into place. A lot of people just pull back the boot, and use spray grease on the front spline. I'm just really picky, and want to make sure both ends are well packed in grease. Oh, and don't forget to put some grease on the splines where the rear wheel engages the final drive gear case. Sorry about the long post, I type really fast. Jerry.
I am a motorcyclist, NOT a biker.
1997 Vulcan 750, purchased about a week ago
2006 Sportster 1200 Low
2013 Royal Enfield Bullet 500, converted to carb
2001 Yamaha XT225, heavily modified
2004 Honda Rebel 250
1979 Vespa P200E
2002 Vulcan 750 parts bike
1994 Yamaha XT225 parts bike