Goliath
Senior Member
The supercharger pulley bearing on my SL55 needed replacing as you can see:
I got a quote from Mercedes for around £2250 to do the job. I much prefer to work on my cars myself so I know the job has been done properly so looked into doing it myself. It can be done easily and quickly, it took me less than an hour with no specialist tools.
Step 1: Order a new bearing, Nachi part number is 45BG07S5DL and costs about £80 or PFI do one for about £30 (http://www.ebay.co.uk/itm/132090277071). I opted for the PFI bearing as it would arrive much quicker than the Nachi one and I need/want to use the car asap. (delivery took less than a week).
Step 2: Tools needed are.... 17mm 12 sided socket/spanner (to remove belt), 24mm socket (to undo pulley bolt), Hose/jubilee clips (130mm or bigger), pliers or circlip pliers, hammer, torque wrench, an oven and a freezer!
Step 3: Remove belt by loosening tensioner with 17mm spanner/socket (12 sided)...
Step 4: Place hose clamps as shown to clamp the supercharger still, do them up tight! (this could scratch the black paint)
Step 5: Use the 24mm socket to undo the supercharger bolt:
Step 6: Once the bolt is out the pulley just slides off with the bearing inside it, then use the pliers/circlip pliers to remove the circlip:
Step 7: Turn pulley up the other way, suspend on 2 blocks either side, place the big washer from the 24mm bolt on the bearing along with the 24mm socket to act as a punch and then tap it with a hammer to remove the bearing from the pulley. It doesn't take a lot of force to remove it.
Step 8: Place the new bearing in the freezer and the pulley in the oven for 15 minutes at 200 degrees (or until golden brown... joke!).
Step 9: Remove new bearing from the freezer and the pulley from the oven and immediately slot the new bearing into the pulley. It should slot straight in, if not will only need a gentle tap with your hand.
Step 10: Refit circlip, then refit pulley onto the supercharger, tighten with a torque wrench to 40 ft/lbs and using the circlip trick above to hold the supercharger still. Don't forget dab of threadlock on the bolt.
Step 11: Refit belt, hey presto, job done!
Now the car runs beautifully and the supercharger pulley is nice and quiet!
Goodness only knows how mercedes can charge £2250 for a £30 (or £80) part and 1 hours labour.
There is a video here (not mine) showing all these instructions too:
https://www.youtube.com/watch?v=TQsVok6BC50&t
I got a quote from Mercedes for around £2250 to do the job. I much prefer to work on my cars myself so I know the job has been done properly so looked into doing it myself. It can be done easily and quickly, it took me less than an hour with no specialist tools.
Step 1: Order a new bearing, Nachi part number is 45BG07S5DL and costs about £80 or PFI do one for about £30 (http://www.ebay.co.uk/itm/132090277071). I opted for the PFI bearing as it would arrive much quicker than the Nachi one and I need/want to use the car asap. (delivery took less than a week).
Step 2: Tools needed are.... 17mm 12 sided socket/spanner (to remove belt), 24mm socket (to undo pulley bolt), Hose/jubilee clips (130mm or bigger), pliers or circlip pliers, hammer, torque wrench, an oven and a freezer!
Step 3: Remove belt by loosening tensioner with 17mm spanner/socket (12 sided)...
Step 4: Place hose clamps as shown to clamp the supercharger still, do them up tight! (this could scratch the black paint)
Step 5: Use the 24mm socket to undo the supercharger bolt:
Step 6: Once the bolt is out the pulley just slides off with the bearing inside it, then use the pliers/circlip pliers to remove the circlip:
Step 7: Turn pulley up the other way, suspend on 2 blocks either side, place the big washer from the 24mm bolt on the bearing along with the 24mm socket to act as a punch and then tap it with a hammer to remove the bearing from the pulley. It doesn't take a lot of force to remove it.
Step 8: Place the new bearing in the freezer and the pulley in the oven for 15 minutes at 200 degrees (or until golden brown... joke!).
Step 9: Remove new bearing from the freezer and the pulley from the oven and immediately slot the new bearing into the pulley. It should slot straight in, if not will only need a gentle tap with your hand.
Step 10: Refit circlip, then refit pulley onto the supercharger, tighten with a torque wrench to 40 ft/lbs and using the circlip trick above to hold the supercharger still. Don't forget dab of threadlock on the bolt.
Step 11: Refit belt, hey presto, job done!
Now the car runs beautifully and the supercharger pulley is nice and quiet!
Goodness only knows how mercedes can charge £2250 for a £30 (or £80) part and 1 hours labour.
There is a video here (not mine) showing all these instructions too:
https://www.youtube.com/watch?v=TQsVok6BC50&t
