99K12LT FD & Slave Not Good! - BMW Luxury Touring Community
 
LinkBack Thread Tools Display Modes
post #1 of 5 Old Oct 13th, 2006, 12:48 pm Thread Starter
Senior Member
 
Join Date: Oct 2003
Location: , Illinois,
Posts: 188
99K12LT FD & Slave Not Good!

On a progressive maintenance day I pulled the FD on my 99 K1200LT with 44,000 miles on it. One order was to really check my rear 020 radial tire with just shy of 21,000 miles for external what evers. No play or sound from the FD whilst checking the 1200/1800 and 2100/1500 for any axial movement. I last R/R the GL 2200 miles ago and the magnetic plug only showed its routine amount of steel flakes (race spalling) in that 4 or 5000 mile interval. You can see the current drain plug mag amount in the photo. No doubt my FD was coming apart and soon. The waste GL was loaded with platelets of the race shoulders. (Shining a light through it created a sparkle shower). I pulled the crown bearing cold with a 3 leg puller (easy) and I think you can see in the macro photo the spalling of the balls. It is of course the old 19 ball FAG German bearing and was within a 100 miles of total self destruction. No chunks of bearing or race showed anywhere and the crown gear and pinon gear are unblemished. After thorough cleaning I replaced the crown bearing with a new 19 ball FAG German bearing. Why BMW has continued to use this same drive which has evolved successfully on its earlier and much lighter m/c(s) is beyond me. Never should be a ball bearing there, rather a hefty tapered roller bearing. When I do this again it will be a non oem bearing of which there are much tougher examples available from various bearing houses.
Now on to the 2nd Achilles Heal of our beloved K1200LT. For those who are waiting to drill their clutch slave mounting boss there on the transmission. The photo should show what you don't want to see. At 40,000 plus miles I have put half the total miles on this machine and ride mostly rural miles. Point being I don't spend alot of time with the clutch lever pulled (ie the throwout bearing is spinning). If you look closely on the photo where I have the Clutch Slave Piston pulled out you can see the old linear scratch that allowed a few molecules of brake fluid to push through each time the clutch lever was pulled. The amount of fluid (about 10 cc) is the total leakage in all 7 years. No fluid was added by me only R/R. The throwout bearing never was overheated and resultingly no evidence of spinning of the piston was in evidence. However it clearly showed the position of the cylinder with its inflow and drain ports at the uppermost by design allows virtually no exchange of fluid from the trapped cylinder bore especially if you suction r/r the brake fluid out the provided port on the bikes right side. Provided BMW shop records and my own records prove this fluid has been timely R/R. The Magura Slave Cylinder et al should have been mounted inverted so all the fluid would be sucked out or driven out. Using the clutch lever/ master cylinder R/R method argubly might be better as it exists. Remember this Achilles Heal affects all years of the K1200LT to my recollection.
BMW has pulled both barrels (Modified & Full Choke) on my beloved LT but I am not daunted! Even one at a time they are easy owner fixes however I could grab the ear of a couple Munich PE's and set them straight. And, yes I do love this wonderful machine. It simply makes me smile to ride it!
Attached Thumbnails
Click image for larger version

Name:	DSC00018(1).JPG
Views:	130
Size:	1,013.6 KB
ID:	7442   Click image for larger version

Name:	DSC00035(1).JPG
Views:	115
Size:	925.8 KB
ID:	7443   Click image for larger version

Name:	DSC00039(1).JPG
Views:	110
Size:	645.3 KB
ID:	7444  

Carl

K1200LT w/ KLT s/c
K1100LT w/ ECC
KLR-650

N9BMN
FD <> 4%
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


bmwmoa 100984

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Tourdog is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old Oct 13th, 2006, 2:07 pm
Senior Member
 
zippy_gg's Avatar
 
Join Date: Jun 2004
Location: Kennesaw, GA, USA
Posts: 8,110
All good info Carl, and nice pics. Glad you caught the bearing before it went out on you. Same with the Slave cylinder.
My bike has over 36 K miles and is still under warranty until December. I am wondering if I should perform a thorough check before the warranty expires and have my dealer replace what needs to be.
This will be my first removal of the FD, and if all checks out OK I will drill the slave cylinder housing while I have everything apart.

Gilles & Kathy
BMWMOA# 154719
IBA# 71594
2011 Ostra Gray RT
06 Mercedes-Benz E350 Estate (parts and people hauler)
2012 BMW X3 (parts and people hauler)
86 Porsche 911 Cabriolet (my "new" baby)



For her I climbed the highest mountain!
For her I swam across the deepest ocean!
For her I walked through the largest desert!
And then she left me... She said I was never home!!!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
zippy_gg is offline  
post #3 of 5 Old Oct 13th, 2006, 3:56 pm
Senior Member
 
dshealey's Avatar
 
Join Date: Apr 2002
Location: Dandridge (Near Knoxville), TN, USA
Posts: 12,165
Question

Quote:
Originally Posted by Tourdog
---------------Never should be a ball bearing there, rather a hefty tapered roller bearing. When I do this again it will be a non oem bearing of which there are much tougher examples available from various bearing houses.-------------------
Good luck on that! Please tell us what you know that we don't! I and other engineers have tried very unsuccessfuly to find any other replacement. I have spent hours looking through bearing interchange lists, manufacturer's catalogs, and web searches, to no avail. SKF France does make the replacement BMW was using for a while, but that one cannot be obtained with any reasonble assurance by BMW dealers. I had the SKF reigonal person here one day, asked about getting a quantity of them to be able to sell them to members. I was assured this would be no problem, but when I got the quote it was over $240 each direct from SKF, in quantity! I told him that they were once being sold by the BMW dealers for around $135, and he had no answer. This is a standard bearing interchange size, but all have basically the same load/speed ratings, so getting a bearing that will fit, but be "tougher", is not really an option. I did buy one with a machined bronze ball retainer/cage, but the hope was that even if the balls/races fail the retainer would not fail catastrophically like the stamped steel ones do, and give you much more warning so that you are not stranded on the side of the road. I totaled my bike before I rebuilt the failed drive I had, and eventually sold the bearing and drive to another member here.

A heavier bearing could be used, but that would take major machining and re-work, with housing parts likely made from billet.

A tapered roller bearing would have to have an opposing bearing of at least 50% the same size, preferably nearly the same size, but that is not feasable with the design of the drive unit.

BMW has totally redesigned the final drive for the later bikes, but we will have to wait a couple years for that to filter down to the hopeful future design for the LT. By the way, the new design still uses one large ball bearing for the main load support.

Now, if you really can find a "better" replacement, the LT world will beat a path to your door.

I don't want to achieve immortality through my work...I want to achieve it through not dying.

David Shealey
Dandridge, TN
EX: '01 Black LT, BAT BYKE (Totaled at 110,000 miles)
IBA SS, BB, BBG, 10/10ths.
No bike now, but maybe in the future.
dshealey is offline  
 
post #4 of 5 Old Oct 13th, 2006, 5:30 pm
Senior Member
 
Join Date: May 2003
Location: North Central Ohio, OH, USA
Posts: 826
Quote:
Originally Posted by Tourdog
Never should be a ball bearing there, rather a hefty tapered roller bearing. When I do this again it will be a non oem bearing of which there are much tougher examples available from various bearing houses.
How can we research getting a replacement tapered roller bearing matchup? Sure would be nice if possible.
hoodoodrum is offline  
post #5 of 5 Old Oct 13th, 2006, 9:13 pm
Senior Member
 
dshealey's Avatar
 
Join Date: Apr 2002
Location: Dandridge (Near Knoxville), TN, USA
Posts: 12,165
Quote:
Originally Posted by hoodoodrum
How can we research getting a replacement tapered roller bearing matchup? Sure would be nice if possible.
I did a bit of work on that, not feasable without building up an entirely new housing design, and for small quantities would have to be billet machined, not something worth the trouble.

I also looked at crossed roller bearings, but none close enough to the correct size to use without major work.

I don't want to achieve immortality through my work...I want to achieve it through not dying.

David Shealey
Dandridge, TN
EX: '01 Black LT, BAT BYKE (Totaled at 110,000 miles)
IBA SS, BB, BBG, 10/10ths.
No bike now, but maybe in the future.
dshealey is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW Luxury Touring Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Oil seal removal from gearbox in front of slave cylinder K12Rick K1200LT 4 Sep 6th, 2012 7:51 pm
Slipping Clutch - Clutch Slave Cylinder lhendrick K1200LT 24 Mar 29th, 2009 7:02 pm
SLAVE "WEEP HOLE" INSTRUCTIONS NEEDED cccpastorjack K1200LT 4 Sep 18th, 2006 8:29 pm
Anyone ever rebuild a slave cylinder? kevincook K1200LT 16 Sep 18th, 2006 9:28 am
Carolina Euro - good rando Dealer Experiences 0 Aug 28th, 2006 7:23 am

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome