How hard is it to replace an alternator bearing

Discussion in 'General Motoring' started by Clara, Jun 16, 2010.

  1. Clara

    Clara Guest

    My 1998 S790 developed a strange noise around the timing belt, that
    was changed a few weeks ago. Went to the dealer and they said that
    it's the alternator bearing that is loose and they want to replace the
    alternator and bearing, and wants to charge a $1000 for it.

    How hard is it to change the alternator bearing by myself? Is it
    doable, or do you need to have heavy machinery to do it?

    Thank you,

    Henry
     
    Clara, Jun 16, 2010
    #1
  2. Clara

    James Sweet Guest


    I've only ever changed the whole alternator, if you can find a source
    for the bearing you could probably take it apart and change it though. A
    new alternator from the dealer is over $400 last I checked, but you can
    likely buy a rebuilt one for much less from a local auto parts store.
    Changing the alternator is not particularly difficult, if you're
    comfortable doing general maintenance.
     
    James Sweet, Jun 16, 2010
    #2
  3. Clara

    Clara Guest

    Thank you James,
    You are correct - the dealer had recommended replacing the alternator.
    The cause is "Alternator Front Bearing is Failing and Noisy. Need to
    Replace Alternator". How much time should I allocate for replacing an
    alternator and is there a good site on the web that would step me
    thourgh the process. I also have the mechanics manual at home...

    Henry
     
    Clara, Jun 16, 2010
    #3
  4. Clara

    Clara Guest

    Found the following http://volvospeed.com/vs_forum/index.php/topic/63411-alternator-replacement/
    -- do I need to re-tention the belts after the replacement? Wonder how
    hard it would be....
     
    Clara, Jun 16, 2010
    #4
  5. Clara

    Henry Guest

    Found this thread that talks about replacing alternator as well:
    http://volvoforums.com/forum/showthread.php?t=36180
     
    Henry, Jun 16, 2010
    #5

  6. right up! but are we sure that it's not an alignment problem? a bolt
    failed on me @ the intersection of nowhere & no brain (grade 8?
    whatdayoumean, i never got out of 5th?) the v belt could no longer
    transmit power (shredded, there is a Jon Deere that fits) & thus the
    alt didn't charge. rebuilt alts are cheap, when i was young & broke, i
    once rebuilt a 4 barrel Weber -- try that in your spare time. your
    choice. 60 US or 3 days asking yourself -- now where do you think that
    goes. i like learning & my money!!!!!

    why are you still talking to a dealer? you are now part of a huge
    community. network!! you will be taken care of. the only requirement
    -- pass it on.
     
    Richard W Langbauer, Jun 16, 2010
    #6
  7. Clara

    James Sweet Guest


    I've never done it on a FWD Volvo, but in any case the challenge is
    access. There are only 2-3 bolts and about as many wires to R&R, but in
    some cars you will swear you need 5 more elbows in your arm to get to
    them. Don't skip the "disconnect the negative battery cable" step that
    any manual starts with. There is often no fuse of any sort between the
    battery and the big red wire on the alternator, and if it shorts to
    something, there is enough current available to set the wiring harness
    on fire.
     
    James Sweet, Jun 17, 2010
    #7
  8. Clara

    Henry Guest

    Thank you for the suggestions. It turns out, based on talking to the
    mechanics, that it is the wheel-and-shaft (on which the belt rests) of
    the alternator that is loose (e.g. wiggles a bit) and that what's
    causing the noise. The dealer just replaced drive belt (and timing
    belt) about a couple of weeks ago. Since I'm not sure in terminology,
    what is the belt that is connected to alternator? And does one touch
    the belt connected to alternator to replace timing belt and drive
    belt? Should I trust them with another repair if I do decide to go
    with a mechanic doing it?

    Of course they told me I have to replace alternator immediately, and a
    new one will be around $1000. Thanks to the posts, I figured I can get
    rebuild alternator for half the price ~$270, and then their labor is ~
    $370. Really tempted to do it myself -- the only big stopper is how do
    I know whether the belt is tight on it after putting the belt back?
    And how hard is it to get the belt off it?

    Sorry for too many questions,

    Henry

    Henry
     
    Henry, Jun 17, 2010
    #8
  9. the rebuild price still seems steep. contact me privately i might have
    a line on better/cheaper.

    oooh!! you raised a # of points. replacement 30 min to 3 weeks (45
    min). 4 hands are better than two (esp if the +2 are young strong &
    stupid). tension? well, you know when you know. it just runs right.
    officially, check deflection -- it should be about 1cm. getting the
    belt off is not a problem a knife, scissors, a rusty spoon. putting
    back together is more of a problem. i think you will need to pop the
    timing & re tension everything.

    this raises another ? WTF? alts don't just break. people put them back
    together usdab & then they fail. whoever replaced the timing belt
    needs to answer a few ?s.
     
    Richard W Langbauer, Jun 17, 2010
    #9
  10. Clara

    Roger Mills Guest

    According to my Haynes manual (I no longer have the car, so I can't
    verify) there is a spring-loaded tensioner which automatically maintains
    the correct tension. It says you have to relieve the tension when
    removing and re-fitting the belt by putting a spanner on the tensioner
    nut and turning it anti-clockwise - i.e. pushing the end of the spanner
    towards the rear of the engine compartment.

    *Sounds* easy enough! (but the reality may be different).
    --
    Cheers,
    Roger
    ____________
    Please reply to Newsgroup. Whilst email address is valid, it is seldom
    checked.
     
    Roger Mills, Jun 17, 2010
    #10
  11. Clara

    James Sweet Guest



    That sounds like a serpentine belt like a friend's Buick used. As lousy
    as that car was, I have to admit it was the easiest most straightforward
    alternator replacement I've ever done. Bolted right to the top of the
    engine and took about 5 minutes to change.


    With V-belts, you tension them until there's about 1" of deflection when
    you push on a span of the belt with your finger. It's not rocket
    science, doesn't have to be exact, but too loose and it squeals, but too
    tight just puts more stress on the bearings.
     
    James Sweet, Jun 17, 2010
    #11
  12. Clara

    James Sweet Guest



    The belt to the alternator is called the alternator drive belt
    generally, sometimes it also drives other things, sometimes a single
    belt wraps this way and that, driving most or all of the engine driven
    accessories, that is referred to as a serpentine belt. Yes, changing the
    timing belt generally involves removing any other drive belts since they
    pass in front of the timing belt. Yes if the alternator shaft wiggles
    at all the bearings are shot and it should be replaced ASAP. It sounds
    like your mechanic is honest.


    If you are comfortable doing basic mechanical work then I think you will
    be fine with this. Get a Haynes or similar manual, read through the
    instructions a couple of times, make sure you have all the required
    tools and parts on hand, and then set about the work. Allow a weekend
    just in case you break something or get stuck, plenty of people here can
    offer you tips if you have trouble. So long as you don't lose any bolts
    or forget how it goes together it should go pretty smoothly.
     
    James Sweet, Jun 17, 2010
    #12
  13. Clara

    Henry Guest

    Thank you for the responces!! I have the Haynes book, have a few links
    on different sites (would be great if there was a YouTube on how to do
    it). Got the part from a store in not too far from my home, paid $110
    (+30 core charge) - much better than Kragen price of ~$270. It is some
    what heavy - will probably need assistance in putting it in (actually
    will be happy to provide assistance for a mechanic that would put it
    in :) ) == Still thinking on whether or not to do it myself - will
    probably start doing it over the weekend, ask for help if I get stuck
    and get a mobile mechanic help if I will realize that I'm in
    trouble :)

    Henry
     
    Henry, Jun 17, 2010
    #13

  14. it seems like you know that weekends can be good/bad. no matter how
    well you plan, there will always be that last little "gevortner" that
    you didn't think of -- or was it a "ramitsframits"? i could quote the
    hhtg, but you know where this is going. always have alternate
    transport. 99% of the time things are easier than they seem. the other
    1% sepaku is the the only option.

    110 seems fine. if it seems heavy, consider Archimedes.
     
    Richard W Langbauer, Jun 18, 2010
    #14
  15. Clara

    Henry Guest

    Well, figured I'm not sure I can do it myself after trying to lift the
    belt and see if the alternator bearing is broken. I tried to ease a
    the belt a bit and my fiance tried to move the shaft of the
    alternator - and then we switched, nothing seemed to be moving.
    Asking a mobile mechanic tomorrow morning if a) we need to change the
    part b) fixing the part and I will help and learn.
     
    Henry, Jun 20, 2010
    #15
  16. Clara

    James Sweet Guest


    You would probably have to remove the belt to tell. The play in the
    shaft may be only a few thousandths of an inch, a good bearing should
    have *no* runout that you can feel.
     
    James Sweet, Jun 20, 2010
    #16
  17. Clara

    Henry Guest

    Well, everything is done now. The old alternator did produce a noise,
    but the shaft was not moving. The new alternator is in place. I'm glad
    I did not do it by myself -- did not have all the tool, and access is
    tough. I helped mobile mechanic to do it though: took him two and a
    half hours - of course it was his first volvo. Half way through the
    project I thought I'll have a bunch of spare parts as opposed to a
    car, but alas the car is all done and running fine.

    Thank you very much for your support!

    Henry
     
    Henry, Jun 22, 2010
    #17
  18. Clara

    Mr. V Guest

    I see you used a "mobile mechanic."

    Not necessarily a bad way to go.

    I was doing a transmission R&R on a Volvo 850R and having never done
    this task on a FWD, I was a bit nervous about pulling the CVCs.

    I called a couple mobile mechanics I found from cragigslist.com, and
    quickly zeroed in on one guy who knew the answers to the questions I
    asked him, to try to prequalify him.

    To make a long story short: a Win-Win situation.
     
    Mr. V, Jun 28, 2010
    #18
  19. First Volvo come one an alternator is an alternator 2.5 hours is
    $$$$$$$$$$$$$$$
    Well, everything is done now. The old alternator did produce a noise,
    but the shaft was not moving. The new alternator is in place. I'm glad
    I did not do it by myself -- did not have all the tool, and access is
    tough. I helped mobile mechanic to do it though: took him two and a
    half hours - of course it was his first volvo. Half way through the
    project I thought I'll have a bunch of spare parts as opposed to a
    car, but alas the car is all done and running fine.

    Thank you very much for your support!

    Henry
     
    Jon Robertson, Jul 17, 2010
    #19
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.