[reveilledog]

Howdy, I recently serviced my AC compressor pulley and did not find any information online to help me actually fix it, so I thought I'd post the process.

E93 328i 6MT

Background: My car started making a knocking sound on the way to class. Made it to class and almost back home, around 15 minutes of driving. I stopped to get gas expecting a long repair and wanting a full tank, and I popped the hood to see if I could see what was going on while I was filling up. I watched parts of my AC compressor pulley fly up and had to get towed a 5 minute walk to my house.



This is what it looked like immediately, the center of the pulley that actually turns the shaft is the triangle looking part in the middle. The snap ring is the bumpy thing around the edge. Behind the snap ring is the innermost part of the pulley bearing.

Pre-Repair: Remove the part of the intake that covers the fan, unplug the coolant line that goes across over top of the fan, unplug the fan, and remove the radiator fan. there is one bolt in the top passenger side corner of the fan and a clip about 1/3 way down the fan on the drivers side. that is all thats holding the fan in. Watch a YouTube video for this to see the process well documented.

Step 1: Remove the center broken triangular piece. I gave mine a good bit of WD-40 and let it sit. I was able to fit a large pair of pliers in from the drivers side in front of the engine block, behind the refrigerant line. Then, from the front, I use a 7mm to rotate the compressor shaft. Once no more compressor shaft protruded from the pulley piece, the triangular piece came off by hand and the shaft had enough resistance it threaded off easily.

Step 2: Remove the snap ring. The holes are partially covered by the groove the snap ring sits in, so use a flat head screwdriver to pry a side out, put the snap ring pliers in that hole, and repeat on the other side. This was much easier with two people



Step 3: Remove the broken piece of bearing. This was my far the hardest part, it took me about 45 minutes to get to this point. There is no good easy way to get a normal pulley puller on this piece because it is flush with the compressor on the back. I had to get a bearing puller set from harbor freight. It was like $90 I think.



You will have to cut the back of the shaft off. I would recommend cutting a slight bit more off than I did so you can get a ratcheting box end wrench in there.

Seat the bearing puller inside the rear bearing seal groove and tighten it down. Make sure you put the clamping piece is in an orientation where both threaded parts have clearance for the studs that come off. I did not have much on either of the studs, but it worked. Normally I would not recommend putting the pushing shaft of the bearing puller on the compressor shaft, but theres not enough room to do anything else. My compressor turned out fine.

The bearing piece slid right off for me once I did this. I also used some WD-40 before I pulled it off.

Step 4: New pulley install. I used this one from EBAY but any should be fine.

https://www.ebay.com/itm/312200002608

Contrary to the name, there is no clutch in this pulley. Remove the plastic center of the pulley with any pry tool and all rubber parts. You will have to do this to get the new snap ring on. My new pulley slid right on the shaft easily.

Step 5: new snap ring. I was able to get the new snap ring in fairly easily. It did not look like it was very well seated, so I used a punch on the snap ring, being careful not to hit the seal behind it, to get it to seat all the way.

Step 5: Pulley Face. The pulley face is what actually turns the compressor shaft. you will have to press fairly hard on the pulley face and turn the pulley at the same time for the threads to catch. I was able to turn it by hand a few turns until I knew the threads were seated well. After that, it started turning the compressor shaft before I could get a socket on it. I jammed a pair of needle nose pliers in the hole on the end of the compressor shaft and pushed them tight. This allowed me to turn the pulley until the compressor shaft stuck out and I could get a socket on it.

Step 6: Torquing the pulley. This is not technically a BMW serviceable part as you could probably guess by now, so there is no torque spec from BMW. I just put the belt back on and tightened on the compressor shaft until the rest of the system started slipping.

I have attached a bunch more photos. They were not inserted right, since if you attach multiple at a time they all insert together, but it's fairly obvious which step each one goes with.

If anyone has any questions let me know and I can try to help. Im not sure this will work on automatic transmission cars because of the transmission oil cooler. I had no clearance issues with the radiator besides the bearing puller, which was an easy fix with an angle grinder.