Hey guys, I replaced my front output flange last night because I discovered some wear on it when replacing some bearings in my transfer case last weekend. I figured I'd write up a quick DIY on it for those that are interested. Replacement is simple so I'm going to make this short and sweet.
This DIY should be used in conjunction with others in this forum for changing your transfer case fluid and pulling the front driveshaft.
This is what we start with:
After draining your transfer case fluid and removing the front driveshaft, use a prybar and pry on the output flange as shown. A small slide hammer would also work here, but my cv axle puller attachment was too small to fit:
This is the flange removed from the transfer case:
Notice the wear/scouring on the flange:
Use a seal puller to pull out the old seal (or your fingers if you're the hulk):
Here is a shot of one of the bearings I replaced in the transfer case last weekend. BMW does not sell any internal parts for our transfer cases, but you can get the bearings from Cobra Transmission:
Use a seal driver to drive the new seal flush with the transfer case. I like to use a little RTV on the outer edge to ensure a good seal:
Apply anti-seize to the splines of the new flange (BMW provides this with purchase of the flange). Press the flange into the transfer case until you can't push it any further, then slightly rotate to align the splines. Once you are aligned, use a rubber mallet to drive the flange all the way into the transfer case.
Now attach your front driveshaft and fill your transfer case with the proper fluid (it takes about 0.6 quarts). Reattach any plastic shielding under the vehicle that was removed for access.
Go for a spin, or have yourself a cold one of your favorite brew.