ADVrider

Go Back   ADVrider > Bikes > GSpot > GS Boxers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-08-2013, 02:28 PM   #1
Rockmuncher OP
Studly Adventurer
 
Rockmuncher's Avatar
 
Joined: Apr 2010
Location: Western Canada
Oddometer: 751
Big Bearing

Waiting for parts to rebuild my final drive. I decided to check the spacing to see if I'm in need of different shims or not. It seems that the consensus on big bearing failure is due to excessive preloading. Watched this video : http://www.bmwlt.com/uploads/lt_final_drive_rebuild.wmv
He says the preload should be .005 to .010.
What do the masses say?
Rockmuncher is offline   Reply With Quote
Old 07-08-2013, 03:05 PM   #2
bemiiten
League of Adventures
 
bemiiten's Avatar
 
Joined: Jul 2003
Location: Hamilton NJ.
Oddometer: 4,776
Did your old bearing fail & how many miles?
bemiiten is offline   Reply With Quote
Old 07-08-2013, 03:35 PM   #3
Steve W.
Boxer Pilot
 
Steve W.'s Avatar
 
Joined: May 2005
Location: Upstate South Carolina
Oddometer: 286
"Taper roller bearing preload mm (in) 0.05 ... 0.1 (0.0020 ... 0.0039)"

Yes that is correct. Quoted per the service manual.

FWIW when I did my 01 GS the factory shims were a .6 and a .15. After replacing the bearing and measuring the play I went back with only the .6 to give it a preload of .08. That was about 8k miles ago. The consensus is the factory got them too tight. Mine did not fail but the old bearing was way "looser" than the new one. I did this as a proactive measure at 50k mi.

Cheers
Steve 01GS 78S
__________________
"Never say Never"

Steve W. screwed with this post 07-08-2013 at 05:36 PM
Steve W. is offline   Reply With Quote
Old 07-08-2013, 05:28 PM   #4
MIXR
Studly Adventurer
 
MIXR's Avatar
 
Joined: Feb 2011
Location: Canberra, Australia
Oddometer: 658
Ditto

My rebuild also had one shim removed to bring it into spec as it was too tight. They certainly go with a bang and rumble when they fail!

__________________
And so ends my 'Adventure' era (SOLD)
IBA # 39193
MIXR is offline   Reply With Quote
Old 07-08-2013, 05:37 PM   #5
def
I've little to say
 
def's Avatar
 
Joined: Feb 2004
Location: The woods and mountains of Alabama
Oddometer: 8,420
Quote:
Originally Posted by MIXR View Post
My rebuild also had one shim removed to bring it into spec as it was too tight. They certainly go with a bang and rumble when they fail!

Egaaaaaaaaaaaaads, that's ugly.
def is online now   Reply With Quote
Old 07-08-2013, 05:48 PM   #6
def
I've little to say
 
def's Avatar
 
Joined: Feb 2004
Location: The woods and mountains of Alabama
Oddometer: 8,420
Quote:
Originally Posted by Rockmuncher View Post
Waiting for parts to rebuild my final drive. I decided to check the spacing to see if I'm in need of different shims or not. It seems that the consensus on big bearing failure is due to excessive preloading. Watched this video : http://www.bmwlt.com/uploads/lt_final_drive_rebuild.wmv
He says the preload should be .005 to .010.
What do the masses say?
I say that you got your decimal point wrong. Move it one place to the right. Also, I assume you are quoting Metric.

My '01 GS REProm says "Taper roller bearing preload mm (in) 0.05 ... 0.1 (0.0020 ... 0.0039).

If I were doing the repair, I would preload to the lower end of the specification say, 0.05mm to 0.07 mm. Also, measure when at room temperature.

Are you going to document your work with photos? Please do and report back here. Thanks.
def is online now   Reply With Quote
Old 07-09-2013, 05:32 AM   #7
Rockmuncher OP
Studly Adventurer
 
Rockmuncher's Avatar
 
Joined: Apr 2010
Location: Western Canada
Oddometer: 751
Quote:
Originally Posted by bemiiten View Post
Did your old bearing fail & how many miles?
The bearing failed, but not catastrophically. I noticed a new vibration in the seat and pegs mostly. After trying to convince myself it was everything but a FD problem, i actually checked it. Definitely a wobble at 12-6. After I took it apart and held the bearing in my hand, I could feel play in the bearing. Cage is still together with all the balls in place. Seal not leaking and no metal filings in the oil.
41000 miles. I've had the bike since 24000 and believe this to be the original bearing.
Rockmuncher is offline   Reply With Quote
Old 07-09-2013, 05:38 AM   #8
Rockmuncher OP
Studly Adventurer
 
Rockmuncher's Avatar
 
Joined: Apr 2010
Location: Western Canada
Oddometer: 751
Quote:
Originally Posted by def View Post
I say that you got your decimal point wrong. Move it one place to the right. Also, I assume you are quoting Metric.

My '01 GS REProm says "Taper roller bearing preload mm (in) 0.05 ... 0.1 (0.0020 ... 0.0039).

If I were doing the repair, I would preload to the lower end of the specification say, 0.05mm to 0.07 mm. Also, measure when at room temperature.

Are you going to document your work with photos? Please do and report back here. Thanks.
Thanks Def, you're right about the decimal and metric.
Going to the looser side of the specs was my thought too. I wonder how many get put together in the factory using the hot bearing, cold crown gear method and aren't allowed to get to room temp before checking the preload. They probably have a whole different setup I guess. Probably involves checking one of every 50 to 100 units. Might explain a lot of failures.
I'll take some pics along the way and put them up.
Rockmuncher is offline   Reply With Quote
Old 07-09-2013, 05:48 AM   #9
Twilight Error
Going nowhere slowly
 
Twilight Error's Avatar
 
Joined: May 2002
Location: The Submarine Mines
Oddometer: 22,393
I just did the big bearing in my final, I did not alter the shims for two reasons:

1. The measured difference in thickness between the old and new bearings was .01mm - the old bearing was thicker.

2. With the new bearing installed and the axle/carrier reassembled and everything at the same temperature, I checked the gear interface with Prussian blue dye and had a good contact pattern on both the ring and pinion. The new contact and old wear patterns were identical, and this drive has gone ~112k miles, so I'm confident everything is happy.
Twilight Error is offline   Reply With Quote
Old 07-09-2013, 08:12 AM   #10
VEGASGSA
Need more Summer
 
VEGASGSA's Avatar
 
Joined: Sep 2009
Location: The Northwet..
Oddometer: 6,594
Quote:
Originally Posted by Twilight Error View Post
I just did the big bearing in my final, I did not alter the shims for two reasons:

1. The measured difference in thickness between the old and new bearings was .01mm - the old bearing was thicker.

2. With the new bearing installed and the axle/carrier reassembled and everything at the same temperature, I checked the gear interface with Prussian blue dye and had a good contact pattern on both the ring and pinion. The new contact and old wear patterns were identical, and this drive has gone ~112k miles, so I'm confident everything is happy.
Interesting..something I've never heard anyone talk about yet..the CONTACT PATCH!!!

The contact patch is everything in the automotive world..does it not matter on FD's as long as the preload is within a wide range??
__________________
Quote:
Originally Posted by JimVonBaden View Post
You are not half as ugly as I thought you would be!
VEGASGSA is offline   Reply With Quote
Old 07-09-2013, 08:56 AM   #11
Twilight Error
Going nowhere slowly
 
Twilight Error's Avatar
 
Joined: May 2002
Location: The Submarine Mines
Oddometer: 22,393
Quote:
Originally Posted by VEGASGSA View Post
Interesting..something I've never heard anyone talk about yet..the CONTACT PATCH!!!

The contact patch is everything in the automotive world..does it not matter on FD's as long as the preload is within a wide range??
I think it does. Moving the contact patch around via shims puts pressure on different points of the tooth faces. If you go too far away from the (for lack of a better term) sweet spot, you can do serious damage to the gears, and no amount of fresh bearings or oil will resolve that.

Adjusting the contact patch is nothing I'd like to get into, I've got only enough experience to say if it looks good or not. If I'd found an unsat condition, I would have brought it to a transmission shop for their opinion.
Twilight Error is offline   Reply With Quote
Old 07-09-2013, 09:15 AM   #12
mouthfulloflake
Not afraid
 
mouthfulloflake's Avatar
 
Joined: Aug 2008
Location: N.W. Arkansas
Oddometer: 15,310
Ive often wondered if anyone alters the pinion depth when measuring and rebuilding a final drive.

Ill assume the bearing on it is shimmed for adjustment as well.
__________________
In dog beers, I've only had one.
Charter member: T.O. club.
Tilt your head, not the taco.
mouthfulloflake is offline   Reply With Quote
Old 07-09-2013, 09:28 AM   #13
def
I've little to say
 
def's Avatar
 
Joined: Feb 2004
Location: The woods and mountains of Alabama
Oddometer: 8,420
Quote:
Originally Posted by mouthfulloflake View Post
Ive often wondered if anyone alters the pinion depth when measuring and rebuilding a final drive.

Ill assume the bearing on it is shimmed for adjustment as well.
During FD repair, the factory REProm provides details as to setting the following parameters;

1- Setting Crown Wheel Bearing preload.
2- Setting the gear tooth contact pattern.
3- Setting pinion to crown wheel backlash.
4- Shimming pinion to crown gear.

When replacing the crown wheel bearing, you need only be concerned about #1.

If you have removed and or replaced any gears, housings or other FD parts, you'll need to be concerned with #2, #3 and or #4.
def is online now   Reply With Quote
Old 07-09-2013, 09:35 AM   #14
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Quote:
Originally Posted by def View Post
1- Setting Crown Wheel Bearing preload.


When replacing the crown wheel bearing, you need only be concerned about #1.

Correct, because the cone bearing prevents any change in depth, not the big bearing.
larryboy is offline   Reply With Quote
Old 07-09-2013, 09:41 AM   #15
mouthfulloflake
Not afraid
 
mouthfulloflake's Avatar
 
Joined: Aug 2008
Location: N.W. Arkansas
Oddometer: 15,310
So the cone bearing is #7 on the parts fiche?

"needle sleeve 15x30x18"

there are shims behing the large bearing on the pinion though.

im just wondering, if the factory did not set up the big bearing preload correctly, would it be logical to assume they have gear mesh set incorrectly as well?
__________________
In dog beers, I've only had one.
Charter member: T.O. club.
Tilt your head, not the taco.
mouthfulloflake is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not 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 On

Forum Jump


Times are GMT -7.   It's 12:19 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014