Page 1 of 20 12311 ... LastLast
Results 1 to 15 of 292

Thread: How to replace your sprag clutch.

  1. #1
    apriliaforum Junkie odie_trackie's Avatar
    Join Date
    Jun 2008
    Location
    San Diego, Ca
    Posts
    348

    How to replace your sprag clutch.

    I just replaced my sprag clutch this weekend. After reading numerous posts on the forum, I was prepared to see a mush of oil, ground up metal parts when I pulled off the my alternator cover. Fortunately, my clutch failed in a "safe" manner. Meaning the only parts damaged was the actual sprag clutch and the bearing housing. Total cost outside of tools: $315.
    I used the Aprilia sprag clutch housing and the Ducati sprag clutch.

    Since there seems to be a lot of people who have done this repair and said "it's not that hard" but don't post pics, I thought I would try and reverse that trend.

    Here's my write up of the repair...with pics.

    Aprilia Sprag Clutch Fix
    Materials/tools required
    14mm hex key
    2-3ft breaker bar or lever arm for a 1/2 drive ratchet
    Various smaller Allen keys (4,5,6).
    small hose clamps
    Oil 5w50 or 10w50
    Oil filter (if it hasn't been changed in a while
    new alternator cover gasket, PN AP0650340
    plumbers torch
    Aprilia flywheel puller
    27mm socket.
    snap ring pliers.
    Verinier or digital calipers.
    Sprag clutch (Ducati equivalent: PN 70140071A about $170 via local Ducati dealer).
    Sprag clutch bearing housing
    Locktite 648 (green).
    Locktite 243 if you remove the alternator from the cover.
    Aprilia V990 engine manual (only $8 download from AF1).
    Lots of clean rags.

    Disclaimer: this is just a guide and I do not claim that it's all comprehensive. Get the manual and follow the directions regarding torque and use of locktite. Do not even think about starting this job without both the bike shop manual AND the V990 shop manual. If you haven't done something like shimmed your values, just take it to the dealer. It took me about 2-3 hours which means, a good Aprilia tech should only take 1.5-2.



    1) Drain the oil.
    1.1) Check for metal particles in the oil.
    2) Remove the oil reservoir
    3) Remove the clutch slave cylinder
    4) Disconnect the alternator connector
    4) Remove the Alternator cover.



    If you can't disconnect the alternator, unbolt it from the cover and hang it on your frame slider.



    DO NOT UNDER ANY CIRCUMSTANCES USE THE STARTER!!!! YOU WILL CAUSE MAJOR DAMAGE TO YOUR ENGINE!!!!!

    5) Check the Sprag clutch operation.
    5.1) Pull out the intermediate starter drive gear.
    5.2) Try to turn the sprag drive gear. It should turn smoothly in one direction only. This by no means that the sprag clutch is good.
    6) Check the condition of the gears between the starter and the sprag gear.
    6.1) The gears take a huge beating if the sprag clutch is failing or if someone tried to start it with the cover off.



    7) Check the condition of the gear shaft bosses on the alternator/starter cover.
    8) Insert the Aprilia Crank Holding tool on the right side of the bike.
    8.1) turn the crank till either the front or rear cylinder is at TDC.
    8.2) screw in the tool (an M8 wing nut bolt)till it stops.
    8.3) Move the crank back and forth a little till you feel the notch in the crank.
    8.4) You should be able to screw in the bolt for 2-3 more turns. This will hold your crank still while you remove and replace the main M16 bolt holding on your flywheel.
    9) Remove the M16 bolt holding on the flywheel
    10) Loosen the bolts holding on the sprag bearing housing.



    11) Use the plumber's torch to heat up the center of the flywheel with the bolt removed (it took me about 1-2 minutes, till it just started to turn a little brown).
    12) Quickly screw in the puller and use the long breaker bar (2-3ft) to apply a medium amount of torque.




    NOTE: it didn't take too much torque to get it off. Be careful not to strip the threads in the flywheel.
    WARNING: The flywheel will be VERY HOT!!!! Handle with care.




    I let it cool for a while before disassembling the flywheel and sprag clutch.

    13) Remove the sprag bearing housing from the flywheel.
    14) Remove the sprag clutch from the sprag bearing housing. PAY ATTENTION TO WHICH WAY THE FLANGE IS ORIENTED!


    15) remove the sprag drive gear.
    16) Check the condition of the inner bearing surface (brass with dimples).
    16.1) The shop manual said 1.382 was the wear limit, my is at 1.378.



    Your can sort of make out the reading on the caliper.
    17) Check the condition of the sprag clutch (outer) surface.
    17.1) should be smooth with not pits or signs of galling.



    18) Check the condition of the sprag clutch.
    18.1) All the engagement pieces should be polished and smooth. Again, my was smooth but I replaced it anyway.



    19.2) The spring holding the whole thing together should be tight. Mine was quite loose.
    19) Check the condition of the sprag bearing housing inner surface.
    19.1) The inner surface shoul be smooth with no gouges, pits or excessive wear. This is the part that was obviously bad on my bike. You can see the gouges worn into the surface.





    20) Replace the sprag clutch parts as necessary.
    20.1) The flange side of the sprag clutch goes against the flywheel.



    20.2) Use the snap ring pliers to squeeze the snap ring to insert the sprag clutch into the bearing housing.
    20.2) Attach the bearing housing and sprag clutch to the flywheel. Follow the shop manual to apply the locktite between the bearing housing and the flywheel and on the bolts.
    20.3) Apply locktite 648(green) to the crankshaft taper.
    20.3) Getting the flywheel/sprag clutch on the sprag drive gear was a little tricky. You have to turn the flywheel in the freewheeling direction and kind of wiggle it to get it on.
    21) Torque the M16 bolt down to 94ft-lbs.
    22) Stop and check that all bolts are tight.
    23) Remove the Aprilia Crank Holding tool.
    24) Make sure the sprag clutch works correctly: slips smoothly in one direction only.
    25) Remove and replace the oil filter at this point if you chose to do so.
    26) Using a new gasket, fit the alternator cover.
    27) Attach the clutch slave cylinder.
    27) Refill the oil and Check all fasteners are tight.
    I didn't take any more pics because I was too nervous at this point.

    28) Make sure the Aprilia Crank holding tool has been removed!
    29) Take a deep breath!
    30) Say a prayer to the Motorcycle maintenance gods.
    31) Fire it up and get the oil pressure up.
    32) Get it warmed up and then check for leaks.
    Last edited by odie_trackie; 08-17-2009 at 07:10 PM.

  2. #2
    apriliaforum expert
    Join Date
    Jan 2007
    Location
    Hammond, Indiana - USA
    Posts
    5,556
    Thanks for the excellent job. I noticed your stator looks good - no sign of heat discoloring the insulation on the wires. It seems every time someone shows us a stator, it's toasted. You mind telling us the history of your bike? Year, mileage, original stator or replacement?
    Hoosier, not hoser.
    2000.5 Mille R - Ti Shotguns & lots of Evo shtuff
    2016 Tuono 1100 Factory

  3. #3
    apriliaforum Junkie odie_trackie's Avatar
    Join Date
    Jun 2008
    Location
    San Diego, Ca
    Posts
    348
    Thanks for the kudos.

    To be honest, the history on this is a little fuzzy. I've been digging into the bike to evaluate it's state of care.

    It seems like the previous owner *used* to take care of it, but it looks like it got neglected as of late.
    He said he did the 13k service last year.

    It's a 2001 RSVR with 18,000miles, Akrapovic exhaust, and the two up seating subframe retro fit.

    The oil looked pretty clean and the inside was pretty clean.

    What causes the alternator stator to overheat?

  4. #4
    apriliaforum Junkie odie_trackie's Avatar
    Join Date
    Jun 2008
    Location
    San Diego, Ca
    Posts
    348
    Oh, I don't know if the stator is original or not. Sorry.

  5. #5
    apriliaforum Member
    Join Date
    Apr 2008
    Posts
    148
    Very Good Write up, it should be a sticky or at least be linked to in a sticky that covers stuff like this.

  6. #6
    apriliaforum expert
    Join Date
    Jan 2007
    Location
    Hammond, Indiana - USA
    Posts
    5,556
    Quote Originally Posted by odie_trackie View Post
    What causes the alternator stator to overheat?
    It's a permanent magnet alternator with a shunt regulator. Current in the stator windings increases with rpm, and so does heat. I don't know if they produced some dodgy stators with marginal insulation on the wires or the diameter of the wire is too small, but some on the forum have been stricken with suddenly smoked stators.
    Hoosier, not hoser.
    2000.5 Mille R - Ti Shotguns & lots of Evo shtuff
    2016 Tuono 1100 Factory

  7. #7
    apriliaforum expert ghostrider71's Avatar
    Join Date
    Oct 2003
    Location
    NUNYA, USA
    Posts
    5,018
    This is a great write-up and I definitely will NOT be doing this MYSELF!!

    Thanks for helping me decide to not butcher my engine on my own...priceless!

    This MUST be stickied...!

    gr
    Since it was highly recommended, I put THEGEEK on ignore and the forum IS a much nicer place!!

  8. #8
    apriliaforum expert Janky's Avatar
    Join Date
    Apr 2006
    Location
    Debeljaca/Serbia/Hungary
    Posts
    585

    Thumbs up

    A lot of people will benefit from your picturesque threads,keep up the good work.
    Janky

  9. #9
    apriliaforum expert soofle616's Avatar
    Join Date
    Jul 2007
    Location
    Middletown, CT
    Posts
    3,273
    my "spare" engine will eventually be getting torn into because of a bad sprag. it would be nice to have this stickied so I don't lose it between now and then.
    I'm on the app store! Check out Solitaire: Slide it's free!

  10. #10
    apriliaforum Junkie odie_trackie's Avatar
    Join Date
    Jun 2008
    Location
    San Diego, Ca
    Posts
    348
    Thank you everyone! I really appreciate it. Ok, so who makes threads sticky?

  11. #11
    apriliaforum expert Janky's Avatar
    Join Date
    Apr 2006
    Location
    Debeljaca/Serbia/Hungary
    Posts
    585
    Sprag clutch (Ducati equivalent: PN 70140071A about $170

    I am very glad that i could help all
    Janky

  12. #12
    apriliaforum expert Sal Khan's Avatar
    Join Date
    Jul 2003
    Location
    Pottsville, PA
    Posts
    2,273
    One of the best write-ups I've seen!

    And now I'm REALLY hoping that never happens to mine!
    Sal Khan

    http://www.thelunchjournals.com - Updated 4/6/08

  13. #13
    apriliaforum expert ARAIHEAD's Avatar
    Join Date
    Nov 2005
    Location
    409 miles from JOHN 'O GROATS!
    Posts
    17,334
    Excellent write up, if ever mine gans, i'll get grahamcoxon to fix it cos he's a bit of a whizz-kid at stuff like that, hell he even managed to change his risers.......EVENTUALLY!!
    The path of the righteous man is beset on all sides by the inequities of the selfish and the tyranny of evil men. Blessed is he, who in the name of charity and good will, shepherds the weak through the valley of darkness, for he is truly his brother's keeper and the finder of lost children. And I will strike down upon thee with great vengeance and furious anger those who would attempt to poison and destroy my brothers. And you will know my name is the Lord when I lay my vengeance upon thee.

  14. #14
    apriliaforum Junkie odie_trackie's Avatar
    Join Date
    Jun 2008
    Location
    San Diego, Ca
    Posts
    348
    Oh, that's right. We have to give credit where credit is due! Thanks for figuring out the Ducati equivalent. That saved me a good $150!!!!


    Quote Originally Posted by Janky View Post
    Sprag clutch (Ducati equivalent: PN 70140071A about $170

    I am very glad that i could help all

  15. #15
    apriliaforum expert Janky's Avatar
    Join Date
    Apr 2006
    Location
    Debeljaca/Serbia/Hungary
    Posts
    585
    Quote Originally Posted by odie_trackie View Post
    Oh, that's right. We have to give credit where credit is due! Thanks for figuring out the Ducati equivalent. That saved me a good $150!!!!
    One for all,all for one!!
    Janky

Page 1 of 20 12311 ... LastLast

Posting Permissions

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