First Full Spline Job and clutch inspection - '93 K75RT 99k miles

[brichbk]

2.5 doesn't sound right.  Have you double checked the zero on your calipers?

Good call.  I recalibrate and measured 4.4-4.3. Still definitely needs to be changed.


I just got back from my local BMW dealership with a bag full of parts.  They had everything in stock, except the starburgas NPU 30 PTM and the clutch alignment tool.


I picked up a new Rear Main Seal.  The parts guy was talking about the special tool that you use to "form" the seal before you put it on.  This was something new to me.  I'll be searching the forum for info on this seal installation.  Is this special BMW tool really needed to install the seal?

[rbm]

No, a special tool is not required. The McGiver method is to use a mallet and wooden block to carefully tap the new seal into place.  Proceed carefully, tapping equally around the circumference, measuring with calipers to ensure that the seal is being driven into place straight and true.  As you approach the face of the casting, slow down and measure often and stop when the face of the seal is 0.5mm proud of the face of the casting.

Another method is to make a wooden drift greater than the diameter of the seal and glue cardboard onto the driving face of the tool, ensuring that there is a hole in the cardboard slightly larger than the seal diameter.  In other words, this cardboard will form an automatic stop when it contacts the casting, ensuring that the seal sits 0.5mm proud of the casting.

In all cases, proceed carefully and resolutely.  You're not in a race to finish the job as quickly as possible.  Measure often to make sure the seal is being driven straight.

There's no need to form the lip of that seal.  It is necessary to form the lip of the timing chain cover seal though, but that's something completely different.  Also it's not necessary to soak the seal in oil prior to installation.  The new seal uses PTFE which doesn't require pre-lubrication.

[brichbk]

In all cases, proceed carefully and resolutely.  You're not in a race to finish the job as quickly as possible.  Measure often to make sure the seal is being driven straight.

There's no need to form the lip of that seal. 

Thanks for all that advice, especially the "proceed carefully and resolutely".  I really want to get this done and I'm working on being patient.

[brichbk]

Well I've made it past the disassembly stage and rounded the corner to the assembly stage.


Got my new Rear Main Seal in. It went in pretty smoothly, tap tap tap tap measure repeat over and over again.  I used a cardboard ring (0.5 mm thickness) I made to help make sure I got to the right depth.  Here are the tools I used for anyone looking for furture reference.






Next is reassembly.  YEEHAWWW!!!

[gone_ape]

Well, Crap..looks like I'm a couple hours late to share, but maybe this will help the next one up....


Before I installed the rear main seal, I took 2000 grit wet dry paper and polished the output shaft to remove and left over teflon or nitirle or what ever on the shaft.



I made a seal driver using the largest deep well socket I had (36mm) and a 3 1/4' Flat washer rtv'd together, the 36mm socket to fit over the output shaft and   once the silicone is set up, it is very strong and still holding together after 4 years or so...


Also, these few special tools are invaluable (well at a menial price anyway) for valve shim service and for sliding the trans in and out for clutch spline lubes... The studs are 4 inch (~100mm) x 8mm bolts with the heads trimmed off...makes reassembly so much easier and minimizes clutch push rod damage especially on the K75.


The inexpensive Clutch alignment tool and valve shim tools are available from:
Kenneth Lively
polepenhollow@yahoo.com

[Laitch]

I made a seal driver using the largest deep well socket I had (36mm) and a 3 1/4' Flat washer rtv'd together, the 36mm socket to fit over the output shaft and once the silicone is set up, it is very strong and still holding together after 4 years or so . . .

+1

[brichbk]

First, I got the clutch put together with the clutch alignment tool spinning easily and got everything put back together.  I adjusted the clutch according to the Clymers manual I have.  It shifts with a little "click" from 0-1 and 2-3-4-5 and back down 5-4-3-2 but going from 1-2 gear it makes a "crruch" noise and same from 2-1 when downshifting (but if at a stands still it does find going from 2-1).  Is there more adjustment I need to make?


Secondly, it seems to be slow to accelerate, is this normal?  I really only notice it when it's below 2.5k-3k RPM.  It really seems to be bad when starting out.  I"m not sure if it's related to the above clutch adjustment or not.  EDIT:  I should also say I just put gas in it for the first time and  I just filled the tank of Chevron Supreme (3.5 gal).  I don't know if the PO had it sitting or not.


Once I get it going it rides smooth.

[johnny]

greetings...

1 to 2 and 2 to 1 have to be made with authority on these motos...

j o

[The Mighty Gryphon]

I can't say why, maybe because it's going through neutral, but shifts between 1st and 2nd are harder than the others.  There seems to be a technique to making that shift that comes from experience with the bike, at least with my bikes.  The amount of clutch pull, and the timing with the actual shift seems to have an effect.

I also found that putting molybdenum powder in the transmission makes things work noticeably smoother.  A couple heaping tablespoons in  the transmission on top of the oil and a hundred miles to work it in.   

[Laitch]

Secondly, it seems to be slow to accelerate, is this normal?

No. If you twist the throttle when it seems to be slow to accelerate, do the revs increase despite slow acceleration?

What did you use for spline lube? How much did you use? Did you lubricate the push rod arm and release bearing? Do you have the side stand release operating smoothly? Review your clutch adjustment measurements—clutch lever free play, cable distance between sheathing and nipple. Then reset the adjusting bolt according to the procedure. What is the level of the transmission fluid when the bike has not been run?

Properly adjusted and lubricated clutch release components and a new clutch disc should allow you to click in and out of gear without "crunching." An excessively high idle can cause "crunching". What is the rev count at idle?

There might have been a problem created when you assembled the boot and its related components or there could be linkage binding and/or improper cable adjustment.

If this were happening with my bike, I'd be compelled to review the assembly and measurement of each component group, starting with the clutch cable, lever and release arm assemblies—checking the affect as I proceed. It's probably some incorrect adjustment easily remedied.

[brichbk]

No. If you twist the throttle when it seems to be slow to accelerate, do the revs increase despite slow acceleration?

The RPM's increase at the same rate the bike accelerates.  I'm wondering if it might be a throttle cable issue?

1.  What did you use for spline lube? 2.  How much did you use? 3.  Did you lubricate the push rod arm and release bearing?  4.  Do you have the side stand release operating smoothly? 5.  Review your clutch adjustment measurements—clutch lever free play, cable distance between sheathing and nipple. Then reset the adjusting bolt according to the procedure. 6.  What is the level of the transmission fluid when the bike has not been run?

1.  Staburagaus NBU 30 PTU
2.  About the same amount as the Chris Harris video shows
3.  Yes
4.  It was disconnected by the PO
5.  I redid the procedure and it is working much better.  I used a piece of stiff wire to measure the clutch cable to get it to 73mm where it was 55mm before.  There is just a little "kerchunk" when going from 1st gear to 2nd gear.
6.  Have not measured the transmission fluid yet.  I'll have to look that up.

Properly adjusted and lubricated clutch release components and a new clutch disc should allow you to click in and out of gear without "crunching." An excessively high idle can cause "crunching". What is the rev count at idle?

There might have been a problem created when you assembled the boot and its related components or there could be linkage binding and/or improper cable adjustment.

If this were happening with my bike, I'd be compelled to review the assembly and measurement of each component group, starting with the clutch cable, lever and release arm assemblies—checking the affect as I proceed. It's probably some incorrect adjustment easily remedied.

Idle is between 800-1,000 RPM

[brichbk]

What is the level of the transmission fluid when the bike has not been run?

Checked the Transmission fluid and found it to be low.  I added about .55l (550ml) to the transmission to bring it up a safe level without going over the max.


I'm going to move my acceleration issues to a new thread.

[The Mighty Gryphon]

It was a HALF LITER LOW?!! :eek:

[Laitch]

Checked the Transmission fluid and found it to be low.  I added about .55l (550ml) to the transmission to bring it up a safe level without going over the max..

It was a HALF LITER LOW?!! :eek:

The correct fluid level might quiet the crunch.   :wave: If you over-filled it might start leaking.

You're asserting it accelerates slowly. Did you ride the bike before you started all this work on it?

[brichbk]

The correct fluid level might quiet the crunch.   :wave: If you over-filled it might start leaking.

You're asserting it accelerates slowly. Did you ride the bike before you started all this work on it?

I found this thread that describes the issue and the video sounds like what I am experiencing.  I figured I'd start with trying to find an air leak.


http://www.motobrick.com/index.php?topic=4157.0