[F30NFifty5]

So after about a month of owning my pre-lci 328 xdrive, I got the triad of death lights on the dash. Fortunately for me, I've experienced the same issue with my 07 X3(RIP), so I figured it was just a worn down gear and not the actual transfer case or actuator. I drove the car in rwd for a bit until I started hearing crunching/clicking under the car whenever the ignition was turned on or off. Thats when I decided it was time to fix it. After a little research I ordered this part off eBay.. a gear puller and a replacement worm gear.

https://www.ebay.com/itm/BMW-transfe...-/293035091998

I took my time getting under the car and taking out the transfer case which was pretty much the same process with the X3. The 18mm bolt at the top of the transfer case bracket was a b***h to get off because it kept hitting on the exhaust when trying to back out the bolt.

After taking off the actuator and separating the part, I found a worn down worm gear, way worse than the plastic gear I replaced on my X3. My local shop cut the top of the gear off and then used a dremel to carve two groves into the side of the new gear(in order for it to fit in the gear puller). Once the old gear was off the new one slid on with the help of a few taps of a rubber mallet.

Once i bolted it back to the car, I couldn't get the bracket back on for the life of me! I struggled for a day and a half before i ended up driving 5mph to my shop to have them do it. Turns out the exhaust needed to be dropped a little by releasing it from the rear hanger. Car has been running great since. I just wished I changed the fluids while I had the bracket off but o well.

[hassmaschine]

Next time, just put that bracket bolt in from the other side. Then you won't need to touch the exhaust in order to get it out.

I'll bet the fluid hadn't been changed and it was binding up. Probably put extra stress on that gear and wore it out. That, and BMW uses cheap materials and parts that are way too small..

[F30NFifty5]

Originally Posted by hassmaschine

Next time, just put that bracket bolt in from the other side. Then you won't need to touch the exhaust in order to get it out.

I'll bet the fluid hadn't been changed and it was binding up. Probably put extra stress on that gear and wore it out. That, and BMW uses cheap materials and parts that are way too small..

One of the youtube videos I watched mentioned the same thing about reversing the bolt. idk how i forgot to tell the mechanic to switch it around but when I do the fluid change i'll be sure to switch it up. Thanks

[roadkillrob]

I did the actuator motor on one of my friends cars about 6 or 7 years ago - worm gear looked exactly the same, car only had 50k miles on it when it went - we had to put a whole motor in it for 400 bucks as no one made the gear back then, they only made the older style, nice to be able to get the $20 part to fix it instead of spending to replace the whole thing. Reversing that bolt whenever you have it out saves you some time for any other maint around the diff!