Greetings K100-forum members. My name is Matthew. I live in Athens, Georgia. I currently own a 1985 K100RS. This is my third Beemer, my second K100RS. My first was a 1985 RS model as well. There always seems to be an early K bike for sale around here for some reason.
I have been visiting this website and availing myself of the invaluable information for quite a while. I finally figured the time had come to make the effort to join. I believe it will be some time before I am able to contribute more than just posing questions for the experts. However, I am most thankful for the other members and guests on my level who have proposed many of the same questions that I've had. If it weren't for those of us who are eager and willing to learn, what would all you K-bike masters talk about?
Anyway, I have managed to complete most all of the essential maintenance tasks thanks to this website and other similarly helpful on-line resources, most notably Chris Harris' YouTube videos - I love that guy! The last major maintenance task (as fas as I'm aware) is the input spline lube. I've managed to do the final drive / drive shaft splines, but as of yet I have not had the requisite downtime needed in order to break the bike down that far and potentially be without transportation for however long. I realize that it is possible to complete this job in a day, but I need to be realistic - it's an '85! Is that pessimism, or am I being realistic? I must say that I would probably never have the confidence to attempt such a thing if I did not have access to all of you guys!
So, I'm hoping to accomplish this before January 6th or 7th.
Thanks in advance for all your help!

- Matthew

Welcome, Matthew, from downunder.

As you've seen, lots of good info and advice here.

Bill

Welcome here and nice intro!
Interesting place you live in.

Cheers from Germany

Greetings Matthew 

Welcome to the forum.

I too am facing a similar situation and found there is only one real solution. Its time to buy another K!

Welcome!  If all you need to do in there is lube the splines you can do what I do.

Get a pair of 8mm bolts about 4" long.  They will allow you to slide the transmission back far enough to go in with a long parts cleaning brush to put some lube on the splines. 

You still have to take a bunch of stuff apart, but at least you don't have to handle the transmission and get it back into the frame.  Saves about an hour or so(and a lot of foul language) on the total job.  It's best to do the clutch splines when you do the final drive since you will have a bunch of what you have to remove out of the way already.

WelKome!

I too have an '85RS but it has no bodywork.

I do have a "C" fairing I will put on.

WelKome!
For what it's worth, my first go at servicing the transmission splines took an entire weekend!  You may be handier with tools of course, but forewarned is forewarned. 
Being that the spline service is very important to the life of expensive components, it's good to do that earlier rather than later.  I found it was good for my peace of mind....
I agree the Chris Harris' videos are really helpful, but I wince at his language at times.

Welcome, Mathew!

Completely removing the transmission allows inspection of the clutch disc splines, a general inspection of the clutch pack area and the transmission case, and allows a more convenient and thorough cleaning of the splines before re-lubing them. Clean and dry spines are critical for the most effective application of lubricating paste

I install guide pins in two diagonally placed bolt holes then slide the transmission completely away from the engine and off the bolts. The guide pins help keep it aligned and help protect the clutch rod. I recall that Harris shows those pins being used. If you're in good enough condition, or have a helper who is also fit, you can remove and install the transmission by using muscle power. Doing it that way is definitely a task for the calm, fit and sober wrencher. For the rest of us, putting a stable, wheeled jack under it to slide it from the engine and to install it is the way to go. 

How much working space you have rules how to proceed. You are wise to leave a couple days for your first shot at this. That should be more than enough if you have paid attention during disassembly. It is a process worthy of a deliberate and unhurried approach anytime but especially when being done by somebody unfamiliar with the assembly. Harris shows the situation and requirements comprehensively.

Start a thread in the Engine and transmission section when you're underway, but Olaf's technique is much more fun.