E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > E46 Xi Forum

E46 Xi Forum
The E46 XI was produced from 01-05 in sedan and touring body styles. Powered by either a 2.5L inline 6 in the 325xi or a 3.0L inline 6 330xi. Discuss all thing about BMW AWD E46 'Xi' here.

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 09-15-2011, 02:21 AM   #81
Fred The Puppy
Registered User
 
Join Date: Jan 2011
Location: Florida
Posts: 40
My Ride: 330XI
Looks like some of you are talking about differentials, and others are talkin' about transfer cases.
Fred The Puppy is offline   Reply With Quote
Old 09-15-2011, 07:40 AM   #82
xixixi
Banned User
 
Join Date: Aug 2009
Location: St Louis, MO
Posts: 3,008
My Ride: 01 330x-xi


I have this exact T case in my garage and performed the exact test. Ever had "locked" diff? Or straight axle? Go try this, come back, start your argument over. How about you buy my T case for 100 bucks and you can tear it apart and educate us all on your vast knowledge of wiki links and videos of your new to you "Locked" T case. You also realize making a system with a 100% locked T case wouldn't allow the abs/dsc to do it's thing right?

Our T case as most already know cause everyone has worked/taken them off before. Has zero electrical connections to it.. As the entire Drive train does minus the transmission (reverse light). Remove a fuse.... hmm sounds like an abs fuse to control the dsc. Now look 1 fuse = unlocked T case... roflmao


Last edited by xixixi; 09-15-2011 at 07:50 AM.
xixixi is offline   Reply With Quote
Old 09-15-2011, 11:12 AM   #83
TiAgXi
Registered User
 
Join Date: Sep 2010
Location: CO
Posts: 999
My Ride: e46xi, e46m
So, I emailed the chief engineer at Magna, the company that owns New Venture Gear. He seems like a pretty good guy and was willing to answer my questions. I've redacted his information, however, so that he doesn't end up hounded by idiots. No doubt, there are those here that are smarter and more experienced than the Chief Engineer at New Venture, so I'm sure debate will continue. In any event, have a look:





/endthread


Last edited by TiAgXi; 09-15-2011 at 11:33 AM.
TiAgXi is offline   Reply With Quote
Old 09-15-2011, 11:39 AM   #84
Pierce1
Registered User
 
Join Date: Nov 2010
Location: LaConner WA.
Posts: 283
My Ride: 03 330xi
Yep, that's how I understand how it works. Nicely done!!!
Pierce1 is offline   Reply With Quote
Old 09-15-2011, 11:57 AM   #85
SamDoe1
Registered User
 
Join Date: Oct 2010
Location: Minnesnowta
Posts: 3,576
My Ride: Clubs baby seals
Quote:
Originally Posted by TiAgXi View Post
So, I emailed the chief engineer at Magna, the company that owns New Venture Gear. He seems like a pretty good guy and was willing to answer my questions. I've redacted his information, however, so that he doesn't end up hounded by idiots. No doubt, there are those here that are smarter and more experienced than the Chief Engineer at New Venture, so I'm sure debate will continue. In any event, have a look:

/endthread

SamDoe1 is offline   Reply With Quote
Old 09-15-2011, 12:18 PM   #86
TiAgXi
Registered User
 
Join Date: Sep 2010
Location: CO
Posts: 999
My Ride: e46xi, e46m
TiAgXi is offline   Reply With Quote
Old 09-15-2011, 02:24 PM   #87
Tele
Registered User
 
Join Date: May 2008
Location: Norway
Posts: 237
My Ride: E46 330XIT MTech II
Informative tread!
My understanding of our 4WD system has always been that you need "some" friction at the tires for it to work.


...Unless you have mechanical locking diffs. and transfer case


Bad ass Buggy!

Last edited by Tele; 09-15-2011 at 02:25 PM.
Tele is offline   Reply With Quote
Old 09-15-2011, 02:55 PM   #88
Thotfulspot
Registered User
 
Join Date: Apr 2011
Location: Flagstaff, AZ
Posts: 219
My Ride: 2003 330Xi
I would assume that Buggy has a Atlas transfer case, mine does. It is gear driven. You get the option of 2WD rear, 2WD rear, 4WD, 2WD front. All of those iterations in low or high range. The only time it would be open is if you put the case in neutral. Besides the clutch based transfer case used in some cars and high end SUVs, that's how truck/jeep etc, that's how transfer cases work. The Atlas allows the front 2WD which most cases don't. Trucks/jeeps etc. Usually just have 2WD rear and 4WD high and low. That's all there is. They are all chain or gear driven. The power is 50/50. There is no option to change the transfer case to open or closed.

Differentials are another story. They come open and you could put a limited slip in which would have the effect of wheels on ice and not being able to move. The other options are ARB (air used to lock it) or Detroit Lockers. Both of these lock the differentials but will allow a axle to go open in a tight turn. The only way to be completely locked is to weld the spider gears.
Thotfulspot is offline   Reply With Quote
Old 09-15-2011, 03:26 PM   #89
jasonbimmer
Registered User
 
Join Date: Sep 2011
Location: Omaha, NE
Posts: 5,686
My Ride: 2001 BMW 330xi
as we were saying, the tcase is a diff type tcase not a chain locking type, otherwise it would not be full time. a full time means the t case always connect front and back diffs allowing different rotation between the front and back drive shafts. I had a wrangler it was a locking part time. you cant turn and should not turn in 4wd mode on dry pavement or you break the tcase (because front and back drive shafts are locked 1:1).
ok since we talking about diff type tcase here, the 38/62 split is done by gears (imagine an open diff with two different size axle gears).
an asymmetrical diff allows torque to be split unevenly. (symmetrical means even split, like our front and rear diff).
however if one drive shaft stops, because of the open diff design, all the power would still go to the other drive shaft.

Last edited by jasonbimmer; 09-15-2011 at 03:31 PM.
jasonbimmer is offline   Reply With Quote
Old 09-15-2011, 03:41 PM   #90
Tele
Registered User
 
Join Date: May 2008
Location: Norway
Posts: 237
My Ride: E46 330XIT MTech II
Quote:
Originally Posted by Thotfulspot View Post
The only way to be completely locked is to weld the spider gears.
I know.

Just trying to make a point by posting the baddest 4WD I could find
But thanks for the Atlas explanation! I’m fascinated by these Buggy’s
Tele is offline   Reply With Quote
Old 09-15-2011, 03:45 PM   #91
TiAgXi
Registered User
 
Join Date: Sep 2010
Location: CO
Posts: 999
My Ride: e46xi, e46m
Quote:
Originally Posted by chuckb View Post
This is largely pointless, i've been going around in circles for a while now. Citing indep resources until i am blue in the face. But since you are resorting to giving people false information to be stubborn and obnoxious, i'll try to put this in a context a child could understand.

Whether you want to call it: open, closed, Dan, or Rita, the values of the transfer case NEVER CHANGE. The BMW literature says this multiple times.

By definition an open diff is variable. It's outputs change. That's what makes it "open".

http://en.wikipedia.org/wiki/Locking_differential:

When the differential is unlocked (open differential), it allows each wheel to rotate at different speeds (such as when negotiating a turn), thus avoiding tire scuffing. An open (or unlocked) differential always provides the same torque (rotational force) to each of the two wheels, on that axle. So although the wheels can rotate at different speeds, they apply the same rotational force, even if one is entirely stationary, and the other spinning. (Equal torque, unequal rotational speed).
By contrast, a locked differential forces both left and right wheels on the same axle to rotate at the same speed under nearly all circumstances, without regard to tractional differences seen at either wheel. Therefore, each wheel can apply as much rotational force as the traction under it will allow, and the torques on each side-shaft will be unequal. (Unequal torque, equal rotational speeds).

What we know:
We know that the t case outpower power is fixed and does not change.

We know that the t case does not provide the same, fixed, torque to both outputs.

We know that the t case output speed is the same to both outputs under all circumstances.


.... You want even simpler??? OK.

"When the differential is unlocked (open differential), it allows each wheel to rotate at different speeds"

BMW: "It uses two open differentials and a single speed transfer case."


One of these things is not like the others, One of these things just doesn't belong, Can you tell which thing is not like the others. By the time I finish my song?

Last edited by TiAgXi; 09-15-2011 at 03:55 PM.
TiAgXi is offline   Reply With Quote
Old 09-15-2011, 04:22 PM   #92
Thotfulspot
Registered User
 
Join Date: Apr 2011
Location: Flagstaff, AZ
Posts: 219
My Ride: 2003 330Xi
It's like beating a dead horse, but from looking at transfer case it is a gear driven case. It works like the Atlas case I described above. The gears can only be engaged, not disengaged or anything in-between without stripping the gears. If it was a fluid/clutch differential it would allow the case to run at different ratios. Where the different speeds come into play is in the differentials. They can run at 4 different speeds if it was on a slippery surface. A stock jeep has the same issue. The brakes being controlled will try to apply some friction to give power to an axle that is slipping. Because of the higher ratio in the rear, it would be easy to get stuck if both rear axles were on ice. there would be situations in snow where the rear would be spinning freely and there was enough resistance against the front like snow.

That's the advantage of the Atlas case and being able to direct 100% of the power to the front axles if needed.
Thotfulspot is offline   Reply With Quote
Old 09-16-2011, 05:12 PM   #93
xixixi
Banned User
 
Join Date: Aug 2009
Location: St Louis, MO
Posts: 3,008
My Ride: 01 330x-xi
so wait... the transfer case is open or locked? I think he was just trolling us!
xixixi is offline   Reply With Quote
Old 09-16-2011, 05:42 PM   #94
Thotfulspot
Registered User
 
Join Date: Apr 2011
Location: Flagstaff, AZ
Posts: 219
My Ride: 2003 330Xi
There is no open or closed in the type of transfer case unless it uses clutches/fluid. The term open or closed applies to differentials. In a differential axles can move at different speeds when traction is lost. The transfer case has a set ratio front to rear and unless you strip the gears, can't turn at any other percentage then set when built.
Thotfulspot is offline   Reply With Quote
Old 09-16-2011, 05:48 PM   #95
Thotfulspot
Registered User
 
Join Date: Apr 2011
Location: Flagstaff, AZ
Posts: 219
My Ride: 2003 330Xi
Whomever has the contact at New Venture should ask if the transfer case can change it's ratio. If it can't it would be considered closed. When discussing most 4WD vehicles there is no discussion of open or closed transfer cases. They are closed and you discuss open or closed differentials.
Thotfulspot is offline   Reply With Quote
Old 09-16-2011, 06:17 PM   #96
TiAgXi
Registered User
 
Join Date: Sep 2010
Location: CO
Posts: 999
My Ride: e46xi, e46m
I've got the contact info. But sorry, I'm not going to bother him. His answer was crystal clear: "The NV124 [transfer case] was an open differential."

You've got yourself stuck in the thinking that because we call it a "transfer case" it's not a "differential." our transfer case IS a differential.
TiAgXi is offline   Reply With Quote
Old 09-16-2011, 06:18 PM   #97
TiAgXi
Registered User
 
Join Date: Sep 2010
Location: CO
Posts: 999
My Ride: e46xi, e46m
Quote:
Originally Posted by xixixi View Post
so wait... the transfer case is open or locked? I think he was just trolling us!
smartass
TiAgXi is offline   Reply With Quote
Old 09-16-2011, 06:31 PM   #98
Pierce1
Registered User
 
Join Date: Nov 2010
Location: LaConner WA.
Posts: 283
My Ride: 03 330xi
Yep. Open differential front to rear instead of left to right. It's that simple.
Pierce1 is offline   Reply With Quote
Old 09-16-2011, 07:19 PM   #99
jasonbimmer
Registered User
 
Join Date: Sep 2011
Location: Omaha, NE
Posts: 5,686
My Ride: 2001 BMW 330xi
Quote:
Originally Posted by Pierce1 View Post
Yep. Open differential front to rear instead of left to right. It's that simple.
its not ordinary open diff. its a unbalanced diff (two axles have different size gears, unlike front and back diffs that have same size gears).
bigger gear means easier to turn than small gear, in our case the rear axle has bigger gear so more torque goes to the rear than the front.

Last edited by jasonbimmer; 09-16-2011 at 07:20 PM.
jasonbimmer is offline   Reply With Quote
Old 09-16-2011, 07:42 PM   #100
Pierce1
Registered User
 
Join Date: Nov 2010
Location: LaConner WA.
Posts: 283
My Ride: 03 330xi
I'm ofcourse generalizing here.
Pierce1 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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
Censor is ON





All times are GMT -5. The time now is 01:03 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use