Results 1 to 3 of 3

Thread: Changing front crank seal on m30B35

  1. #1
    Join Date
    Sep 2007

    Default Changing front crank seal on m30B35

    How long should it take me to change the seal? Do I need any 8 foot long breaker bars to do this or just remove the bolts holding on the pulley/dampener?
    I've been avoiding this since the car has been sitting in the driveway but since I sold the e30 that was taking up my time, it's turn has come.

    1990 535im 421,000 miles, 1987 325is, 1989 325is, 1990 m3, 1991 318is, 2001 X5 3.0

  2. #2
    Join Date
    May 2004


    First check this: One of the 2 bolts that supports the crank reference sensor bracket is a very common leak on m30's. Here's more info:
    Another comment: I did mine on my 87 535is, and I am not a professional. I did have to make/fabricate a big beefy bar that I could bolt to the front of the crank to hold it still by letting the end of the bar wedge on the ground, and after i destroyed two 1/2 breaker bars and borrowed a 3/4" breaker bar, it was not bad at all. I have heard it may not be good for the engine to use an impact on the nut, so I didn't. Some others may know better about that.

    Front oil seals - renewal
    M10 and M30 (timing chain) engines
    Camshaft front seal (M30 engines only)
    1 Remove the upper timing chain cover only (see Section 7).
    2. Support the cover on two blocks of wood, and drive out the seal from behind with a hammer and screwdriver. Be very careful not to damage the seal bore in the process.
    3 Coat the outside diameter and lip of the new seal with multi-purpose grease, and drive the seal into the cover with a hammer and a socket slightly smaller in diameter than the outside diameter of the seal.
    4 The remainder of refitting is the reverse of removal.
    Crankshaft front seal (M10 and M30 engines)
    5 Remove the crankshaft pulley and vibration damper (see Section 7).
    6 Carefully prise the old seal out of the cover with a large screwdriver. Be very careful not to damage the seal bore or the crankshaft with the tool. Wrap the tip of the screwdriver with a piece of tape to prevent damage.
    7 Clean the bore in the cover, and coat the outer edge of the new seal with engine oil or multi-purpose grease. Also lubricate the lips of the seal with multi-purpose grease. Using a socket with an outside diameter slightly smaller than the outside diameter of the seal,carefully drive the new seal into place with a hammer (see illustration). If a socket isn’t available, a short section of large-diameter pipe will work. Check the seal after refitting to be sure the spring around the inside of the seal lip didn’t pop out of place.
    8 The remainder of refitting is the reverse of removal.

  3. #3
    Join Date
    Dec 2004
    Sydney, Australia


    Good advice there :-)

    Much easier if you have a manual, but 330ft/lbs on that 37mm ? nut is a lot of tension. BMW have a special tool (high tensile locking pin) that goes into the fly wheel at the back through a small hole near the starter motor. If you have a manual you can leave her in gear, but its a lot of force to put on everything. The twist on the long M30 crankshaft is not insignificant even if you are using the proper tool to prevent everything turning with the breaker bar.

    No matter what, to do it you have to be ready with a decent 8' long breaker bar. Longer if you can. I had to hang off mine quite a bit before it gave way.

    Join the Aussie
    540i LE yahoo forum

    08/88 535i e34 M30+miller MAF, 'stiens, tints & teeth!

Similar Threads

  1. Replacing front crank seal - what else?
    By J.DeFeo in forum 5 Series BMW
    Replies: 2
    Last Post: 06-22-2008, 02:55 PM
  2. M50TU Front Crank Seal
    By Aaron Bakos in forum 5 Series BMW
    Replies: 4
    Last Post: 09-17-2006, 09:20 PM
  3. Need Advice on Changing Rear Main Seal
    By RayC. in forum 5 Series BMW
    Replies: 5
    Last Post: 10-12-2005, 05:59 PM
  4. Front crank oil seal
    By Anton CH. in forum 5 Series BMW
    Replies: 3
    Last Post: 08-02-2005, 11:48 AM
  5. Front Crankshaft Oil Seal
    By Hector in forum 5 Series BMW
    Replies: 16
    Last Post: 04-01-2004, 02:16 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts