Engineer type Question - BMW Luxury Touring Community
 
LinkBack Thread Tools Display Modes
post #1 of 17 Old Apr 30th, 2009, 3:45 pm Thread Starter
Junior Member
 
Join Date: Oct 2004
Location: Scottsdale, AZ, USA
Posts: 12
Engineer type Question

Looking for a reason for failure.

2005 K1200LT at 36,000 miles had rear end torn down, rear end smaller bearing race had spun on shaft. I believe the inner race to shaft is to be a slight interference fit and the tapered bearing showed no evidence of damage or lack of lubrication.

Is this a case of latent defect from manufacturing/assembly?

Or is there an engineering explanation for this outcome? I am at a loss to determine a cause.

See attached Photo 1 showing shaft damage
Photo 2 showing bearing in place loose on shaft
Attached Thumbnails
Click image for larger version

Name:	1.jpg
Views:	229
Size:	402.0 KB
ID:	22847   Click image for larger version

Name:	2.jpg
Views:	214
Size:	416.0 KB
ID:	22848  
DLundberg is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old Apr 30th, 2009, 4:07 pm
Senior Member
 
CharlieVT's Avatar
 
Join Date: Jun 2002
Location: The Deep South of Vermont
Posts: 4,389
Re: Engineer type Question

Yup, machining defect. Not the most common form of KLT final drive failure, but known to occur. Others have reported this failure mode, seems like the year 2005 was the year for this failure. (Earlier bikes more commonly had crownwheel bearing failure, and tapered roller bearing was fine.)

Shaft/seat for tapered roller bearing apparently machined too small resulting in spun bearing. I have rebuilt one final drive with Locktite 600 (this was not a failed final drive, but rather one where I found the bearing to be loose during an inspection).

The pic you posted shows the shaft/seat not looking too bad. I'd consider rebuilding that drive with loctite 660 and using it as a spare final drive. A better rebuild would involve replacing the crown wheel assembly.... but when you evaluate the cost, getting a whole new final drive may make sense.
Here's the Loctite product engineered for this kind of application:
http://www.useloctite.com/products/p...inery%20Repair

More final drive rebuilding info here:
http://www.bmwlt.com/uploads/lt_final_drive_rebuild.wmv

Thanks for posting your photos and description of your failure.



Quote:
Originally Posted by DLundberg
Looking for a reason for failure.

2005 K1200LT at 36,000 miles had rear end torn down, rear end smaller bearing race had spun on shaft. I believe the inner race to shaft is to be a slight interference fit and the tapered bearing showed no evidence of damage or lack of lubrication.

Is this a case of latent defect from manufacturing/assembly?

Or is there an engineering explanation for this outcome? I am at a loss to determine a cause.

See attached Photo 1 showing shaft damage
Photo 2 showing bearing in place loose on shaft

Last edited by CharlieVT; Apr 30th, 2009 at 4:15 pm.
CharlieVT is online now  
post #3 of 17 Old Apr 30th, 2009, 5:25 pm Thread Starter
Junior Member
 
Join Date: Oct 2004
Location: Scottsdale, AZ, USA
Posts: 12
Re: Engineer type Question

Thanks Charlie
Wonderful video I just finished watching it.

Yes your suggestion looks like the way to go. You are right by the time both the pinyon gear and drive gear (set) and bearings, shims etc with labor the price is with in $100 of a new unit with labor to instal.

I am very tempted by the locktite solution even at this stage.
DLundberg is offline  
 
post #4 of 17 Old Apr 30th, 2009, 9:17 pm
Senior Member
 
gbob's Avatar
 
Join Date: Sep 2006
Location: Nevada, MO, USA
Posts: 461
Re: Engineer type Question

Hello DLundberg

If the shaft is not too bad I would take it to a machine shop and have it knurled , that will raise up enough metal to take up a couple thousands slop .

Bob G
gbob is offline  
post #5 of 17 Old May 1st, 2009, 4:05 am
Senior Member
 
Join Date: Mar 2005
Location: Palma de Mallorca
Posts: 1,985
Re: Engineer type Question

Does the Loctite 660 "glue" the bearing onto the shaft ?.
simoncharles is offline  
post #6 of 17 Old May 1st, 2009, 5:17 am
Senior Member
 
CharlieVT's Avatar
 
Join Date: Jun 2002
Location: The Deep South of Vermont
Posts: 4,389
Re: Engineer type Question

Quote:
Originally Posted by simoncharles
Does the Loctite 660 "glue" the bearing onto the shaft ?.
Loctite application guide:
http://www.useloctite.com/filephotos...ions_Guide.pdf
CharlieVT is online now  
post #7 of 17 Old May 1st, 2009, 6:08 am
Senior Member
 
Join Date: Mar 2006
Location: West Milford, NJ, USA
Posts: 978
Re: Engineer type Question

Quote:
Originally Posted by DLundberg
Looking for a reason for failure. ....
What were the symptoms of that particular failure? What prompted you to open the drive?

Robert in Northern NJ

'09 R12GS, '08 R12RT, '03 R1150RT, '01 F650GS - time to thin the herd?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rdwalker is offline  
post #8 of 17 Old May 1st, 2009, 8:25 am Thread Starter
Junior Member
 
Join Date: Oct 2004
Location: Scottsdale, AZ, USA
Posts: 12
Re: Engineer type Question

The bike went in for its 36,000 mile service. The service tech said the rear wheel had side to side play while on the lift. So I authorized the tear down to determine the problem. As a side note the head shake at 42 mph has been getting worse. It will be interesting to see if the head shake goes away after the rear end is repaired.
DLundberg is offline  
post #9 of 17 Old May 4th, 2009, 2:52 pm
Guest
 
11862's Avatar
 
Join Date: Apr 2006
Location: minnetonka , mn, usa
Posts: 637
Re: Engineer type Question

Grinding an external diameter undersize for a pressed-on bearing is just lousy manufacturing quality control. This isn't rocket science. It should have been caught at the grind stage, and then again at the assembly stage.

A Russian emigre' friend noted that in the bad old Commie days, such scrap was always saved for future "spare parts". Was something even worse going on at BMW?

I'm starting to change my mind on FD failure reasons. Maybe it is just poor BMW quality.

You could try the Locktite but that doesn't give the pressed-on effect to retain the inner race with the shaft, and there will eventually be rotation between the two. I'd be inclined to try a stainless or even aluminum foil shim sleeve and heat/shrink the two together using an oven (250 degF) and some liquid nitrogen (~-350 degF) I think you can get shim stock down to about .0015" or even .0010" thickness.

MN Engr (retired)
11862 is offline  
post #10 of 17 Old May 4th, 2009, 5:29 pm
Senior Member
 
CharlieVT's Avatar
 
Join Date: Jun 2002
Location: The Deep South of Vermont
Posts: 4,389
Re: Engineer type Question

Quote:
Originally Posted by niel_petersen
Grinding an external diameter undersize for a pressed-on bearing is just lousy manufacturing quality control. This isn't rocket science. It should have been caught at the grind stage, and then again at the assembly stage.....I'm starting to change my mind on FD failure reasons. Maybe it is just poor BMW quality....
Yeah, that's my vote. Improper external dimenensions have been reported for the crownwheel bearing seat, the tapered roller bearing seat, and for the crownwheel assembly itself where the crownwheel gear (steel) is pressed onto the crownwheel shaft (aluminum) (reported in BMWON). That constitutes ALL THREE machined external diameters on the crown wheel aluminum piece. I think that former Soviet Block East Germans, now working for BMW (Google the managment problems that West Germany has had after reunification) have been working the machining/assembly line at BMW. The final drive failures can be attributed to the sloppy work and poor work ethic of workers of that background. (Just my opinionated opinion )
CharlieVT is online now  
post #11 of 17 Old May 4th, 2009, 6:24 pm
Senior Member
 
RonKMiller's Avatar
 
Join Date: Jul 2003
Location: Tucson, AZ, USA
Posts: 6,279
Re: Engineer type Question

Quote:
Originally Posted by CharlieVT
Yeah, that's my vote. Improper external dimenensions have been reported for the crownwheel bearing seat, the tapered roller bearing seat, and for the crownwheel assembly itself where the crownwheel gear (steel) is pressed onto the crownwheel shaft (aluminum) (reported in BMWON). That constitutes ALL THREE machined external diameters on the crown wheel aluminum piece. I think that former Soviet Block East Germans, now working for BMW (Google the managment problems that West Germany has had after reunification) have been working the machining/assembly line at BMW. The final drive failures can be attributed to the sloppy work and poor work ethic of workers of that background. (Just my opinionated opinion )


McCarthy was RIGHT after all!

It WAS a communist plot!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
"Like Butt-ahh!"
RonKMiller is offline  
post #12 of 17 Old May 4th, 2009, 10:16 pm
Senior Member
 
pushin9s's Avatar
 
Join Date: Feb 2007
Location: Maryville, TN, US
Posts: 312
Re: Engineer type Question

As for the Locktite fix? I know at the machine shop at Delta airlines they use a plasma spray to build up engine parts that have been worn beyond limits. The plasma spray is very durable and can be built up then machined back down to the proper specs. I don't know if this kind of process is available to the average Joe, but it may be something worth looking into.

Whatever you decide, I hope your new/rebuilt final drive lasts you a good long time and you can recapture the joy of riding your LT.
pushin9s is offline  
post #13 of 17 Old May 4th, 2009, 11:32 pm
Guest
 
11862's Avatar
 
Join Date: Apr 2006
Location: minnetonka , mn, usa
Posts: 637
Re: Engineer type Question

Plasma spray would work, or even hard chrome plate the diameter and grind to proper size, depending on how undersize it is.
11862 is offline  
post #14 of 17 Old May 5th, 2009, 8:57 am
Member
 
Join Date: Aug 2008
Location: Cumming, Ga, USA
Posts: 62
Re: Engineer type Question

Call me crazy and I'm not sure that I would trust it or that it would work but what about aluminum foil tape? No not duct tape but the actual aluminum foil tape that's used in duct work A wrap or two then shrink fit using the oven and freezer method.

Frank Carroll
Cumming, Georgia

2003 K1200LT
2003 Kawasaki Vulcan 1500 Classic
jarhead354 is offline  
post #15 of 17 Old May 5th, 2009, 9:39 am
Lifetime Supporter
 
deanwoolsey's Avatar
 
Join Date: Aug 2008
Location: Topeka, KS, USA
Posts: 3,105
Re: Engineer type Question

Knurl the shaft, use the Loctite when you mount it and hope like hell you never have to take it apart because that stuff works as advertised. Anyway it did on my old Mustang brake hub where the outer bearing race spun.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
deanwoolsey is offline  
post #16 of 17 Old May 5th, 2009, 9:46 am
fas
Senior Member
 
fas's Avatar
 
Join Date: Jul 2002
Location: Bay Village, OH, USA
Posts: 807
Re: Engineer type Question

Quote:
Originally Posted by niel_petersen
Grinding an external diameter undersize for a pressed-on bearing is just lousy manufacturing quality control. This isn't rocket science. It should have been caught at the grind stage, and then again at the assembly stage.

A Russian emigre' friend noted that in the bad old Commie days, such scrap was always saved for future "spare parts". Was something even worse going on at BMW?

I'm starting to change my mind on FD failure reasons. Maybe it is just poor BMW quality.

You could try the Locktite but that doesn't give the pressed-on effect to retain the inner race with the shaft, and there will eventually be rotation between the two. I'd be inclined to try a stainless or even aluminum foil shim sleeve and heat/shrink the two together using an oven (250 degF) and some liquid nitrogen (~-350 degF) I think you can get shim stock down to about .0015" or even .0010" thickness.

MN Engr (retired)

+1

FD would never meet six sigma. I would love to get my hands on the design calcs and tolerances of this FD.

Rob Nelson

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



2006 K1200GT [now lives in Wisconsin]
Grey Goose
2002 K1200LTC [now lives in Georgia]
Toscana Temptress

More than 132,000 (recently corrected higher) motorcycle riders have died in traffic crashes since the enactment of the Highway Safety Act of 1966 and The National Traffic and Motor Vehicle Safety Act of 1966. Be careful out there.
fas is offline  
post #17 of 17 Old May 9th, 2009, 10:23 pm
Member
 
gearman's Avatar
 
Join Date: Nov 2005
Location: Riverside, Il, USA
Posts: 79
Re: Engineer type Question

By the looks of the contact patern on the coast side of the ring gear, it's gonna be noisy!
The bad bearing allowed the pattern to move, wearing a different pattern on the teeth.
gearman 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
Engineers Lynn_Keen Humor 12 Mar 2nd, 2008 8:15 pm
Cigarette type plugs powwow Satellite Radio 8 Jun 30th, 2007 3:26 pm
Dog-Gone battery charger question! Yuck! wardenross K1200LT 17 Oct 24th, 2006 1:31 pm

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