Guess what? Another t-case issue.

[nonturbodan]

I'm surprised I never heard about this until now but the wife's 04 3.0 came home yesterday with the dash lit up and the t-case clutch pack engaged so strongly that the car would not move with the steering at full lock. I ordered the gear but was hoping to keep driving the car with the front driveshaft removed. Easy enough to try. Turns out you can drive it like that but only until the flange at the transfer case end pops out and begins dumping the oil out. Not really a viable option.

I have not pulled the actuator yet but I suspect the gear is toast. Its got about 170k miles on it so I'm kind of surprised it made it this far.

Upon removing the front driveshaft it appears that one of the u-joints is in poor condition so I'll be picking up a new one of those as well. From what I can see it looks like the e46 XI uses the same shaft, though the part numbers are different. Considering how common the e46 parts are I think I'll pick one up just to see if it works.

Only question I have is regarding the internal design of the transfer case. From what I can find it looks like it drives the rear wheels full time and uses the clutch pack to transfer power to the front wheels as needed. If this is correct I could fabricate a bracket to keep the front flange fully seated and continue to operate the vehicle as a rear wheel drive X3. I would use a sealed ball bearing against the flange to keep it in place as it rotates as soon as the vehicle is in motion. Seems like it would be pretty easy to fab up and it would take all of the load off of the transfer case. AWD isn't really a requirement for me. Don't have much need and I find RWD to be perfectly fine in snowy and icy conditions on the rare occasions that we do see them.

[asphalt4463]

Unless you're a good fabricator and not willing to potentially strand your wife, I'd rebuild the tcase and not delete the front driveshaft and diff. Wouldn't you also need to deal with what to do with the front axles, hubs, and then have wheel speed sensor problems? Just thinking out loud here.

[nonturbodan]

Fabbing up a bracket is nothing. There is no load on the flange pushing it outward other than its own inertia during braking. I'm thinking a small diameter sealed ball bearing just off center of the flange and a simple steel bracket to the nearest threaded hole.

The DSC wouldn't know the driveshaft is disconnected unless she's doing some serious off roading. I will repair the VTG actuator in any case, so as long as it works and passes its internal self checks I bet it doesn't set any faults.

According to pelican:
http://www.pelicanparts.com/techarti..._Replacing.htm

The rear axle is driven at all times by the transmission output. The clutch pack in the transfer case can lock the front and rear axles together and the DSC can attempt to direct power between the two wheels on each axle. With the shaft disconnected the front axles and diff will freewheel under no load, as will the tcase. In the event of the VTG engaging and attempting to drive the front wheels the flange will continue to spin freely as it does any other time. Since the rear shaft is engaged full time the transfer case cannot prevent torque from going to the rear wheels, it can only connect or disconnect the front axle on command.

Seems like it could work.

[asphalt4463]

I'm interested to hear how it works out for you; sounds like it would work fine based on your logic. Another thing to keep in mind is the height of an x3 over say a 3 or 5 series and if the awd helps with the disadvantage of the higher center of gravity. Just my opinions here.

[02TT]

Good Morning,

I recently (5 months ago) repaired the transfer case in my wife's 07 X3, so I am pretty familiar with the internals and there operation.

You are correct, the rear axle is driven at all times and never disconnects.

If you remove the actuator motor, the springs in the clutch pack will release the clutches and the front axle will not be driven. then the mounting pad for the actuator could be covered up pretty easily to keep out debris until your gear comes in.

Hope this helps,

[nonturbodan]

Good Morning,

I recently (5 months ago) repaired the transfer case in my wife's 07 X3, so I am pretty familiar with the internals and there operation.

You are correct, the rear axle is driven at all times and never disconnects.

If you remove the actuator motor, the springs in the clutch pack will release the clutches and the front axle will not be driven. then the mounting pad for the actuator could be covered up pretty easily to keep out debris until your gear comes in.

Hope this helps,

Good information. Thank you.

[nonturbodan]

Car is fixed. The VTG gear was stripped. The previous owner had told me that the transfer case had been replaced by BMW and he was right. Date code on the old gear indicated it was produced in 2014. I don't think it could have more than 40 or 50 thousand miles on it at the most. Probably more like 30-40. Not good.

Also replaced the tcase fluid while I was in there. The old stuff looked good, just a darker shade of amber than what went in. I was very tempted to try some Honda Dual Pump fluid which is $8 but I wussed out. Couldn't justify gambling the tcase on a $40 difference.