|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Front diff and transfer case weakest link?
|
|
06-21-2016, 07:37 AM | #1 |
Private
57
Rep 56
Posts |
Front diff and transfer case weakest link?
I keep seeing that the front diff is supposively the weak link in the xdrive, but I can't find any photos of the diff internals, a damaged unit internals, and I'm having a hard time finding any first hand info from someone who actually broke theirs.
It sounds like the transfer case is probably pretty good overall, but the actuator wants to change faster than the gears can handle... And still no way to control it. Does this sound correct? It would seem that IF there was a way to control it, or at least slow down its movement, then all would be fine..? Does anyone have a broken actuator or front diff? I want to start taking these apart and trying to figure out some solutions before I go further in my setup (still a year or two away, but that's not a long time to try and solve these problems)! |
06-21-2016, 11:07 AM | #2 | |
Curmudgeon and Pedant
690
Rep 3,489
Posts |
Quote:
As for the center diff (it's actually not a diff, it's a transfer case) the weak spot is the gears. The X3 forums are the best place to look for explanations. (note that my '01 330xi had a different xfer case, so I'm not speaking from experience here). Both the drive and driven gears are plastic. The center portion of the gears - where they spend most of the time - got/get worn and eventually they cause a fault - often the DSC light comes on, sometimes there is clattering, etc. I don't believe that the xfer case's power transfer gears are actually a problem. |
|
Appreciate
0
|
06-21-2016, 03:06 PM | #3 |
Private
57
Rep 56
Posts |
One of the reasons I want to see an actual failed front diff (from 335xi) is to see if it was a mechanical failure, or lubrication failure, overheating, ring and pinion gears stripped, CV splines strip, etc.
To your point on the .5 pints of fluid, if they were failing on road courses or normal driving then I would tend to agree that this is a huge failure point... But it sounds like a lot of failures happen on hard or poor launches (again hard to find first hand examples). The plastic gears are in the actuator housing, which seams to have more failures at higher power levels (though stock is common too). It sounds like the failures are from having to switch from RWD to AWD more quickly and thus strips the gears faster. I haven't really seen/heard of transfer case failures, but lots and lots of failures in the actuator planetary and worm gears. |
Appreciate
0
|
06-22-2016, 05:41 AM | #4 |
Lieutenant
89
Rep 452
Posts |
There is abolutely nothing plastic in E9X actuators...that was on old X3 ones,the weak part in transfer case is the Friction Clutch Assembly and front and rear flange bearing. On front differential i saw few of them with broken or very rough front pinion bearings.
|
Appreciate
0
|
06-23-2016, 01:02 PM | #6 |
Private
57
Rep 56
Posts |
Awesome, those are the first photos I've seen inside the front diff. Do you know what the failure was? And when did the failure happen, hard launch, normal driving, etc.?
Also sent a PM to see if you still have it and any interest in selling it. |
Appreciate
0
|
06-23-2016, 02:06 PM | #7 | |
Major
110
Rep 1,340
Posts |
Quote:
|
|
Appreciate
0
|
06-29-2016, 10:45 PM | #9 |
Private
57
Rep 56
Posts |
Thanks Julian for checking on the diff for me. I'll keep looking around. Anyone who has one, damaged or working, please let me know! Would prefer to get a manual one that has the 3.08 gears (not sure if gears changed on later models).
|
Appreciate
1
|
07-08-2016, 07:30 AM | #10 |
Major
110
Rep 1,340
Posts |
|
Appreciate
0
|
Bookmarks |
|
|