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Thread: Post here if you've had prematurely worn cam lobe(s) in your wethead

  1. #331
    Quote Originally Posted by PGlaves View Post
    Once correctly set does the cam timing change???
    I set my 2017 R1200RT at 9k miles, and the cam timing was off. Since then, I now have ~25k miles and have checked 3-4 times and the cam timing has been spot on. The clearances have been adjusted once during that period, without influencing the timing.

    Cap

  2. #332
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    Glancing at this thread for the first time and have not read all of it so maybe this has been covered...

    From the few posts that I have read this problem/cause may be similar to what Ducati was dealing with in the early 2000's... and I dealt with on my ST4.

    The problem as described by a vendor of replacement rockers...


    "Q. What is the actual cause of rocker arm failure?

    A. The most common failure "Flaking" ("Peeling") is caused by cracking and separation of the hard plated surface from the base material. The stock arms are cast from metal that is plated in the areas that are contacted by the cam shaft. The plating is a very hard and abrasion resistant material but it is also very brittle. The cast metal is porous, nodular, and relatively soft in comparison to the plating. Under normal operating conditions the cam shaft not only slides over the rocker arms it also impacts the face of the arms on each revolution. The plating is well suited to provide abrasion resistance from the sliding action but due to its brittle nature can not withstand impacts. The cam shaft impacting the surface of the rocker arm causes the plating to indent into the the cast metal material below and fracture. The fractured plating then peals off of the cast metal. The cam shaft lobes are then damaged by contact with the abrasive cast material."

  3. #333
    Registered User LFarling's Avatar
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    Quote Originally Posted by GIARCG View Post
    Glancing at this thread for the first time and have not read all of it so maybe this has been covered...

    From the few posts that I have read this problem/cause may be similar to what Ducati was dealing with in the early 2000's... and I dealt with on my ST4.

    The problem as described by a vendor of replacement rockers...


    "Q. What is the actual cause of rocker arm failure?

    A. The most common failure "Flaking" ("Peeling") is caused by cracking and separation of the hard plated surface from the base material. The stock arms are cast from metal that is plated in the areas that are contacted by the cam shaft. The plating is a very hard and abrasion resistant material but it is also very brittle. The cast metal is porous, nodular, and relatively soft in comparison to the plating. Under normal operating conditions the cam shaft not only slides over the rocker arms it also impacts the face of the arms on each revolution. The plating is well suited to provide abrasion resistance from the sliding action but due to its brittle nature can not withstand impacts. The cam shaft impacting the surface of the rocker arm causes the plating to indent into the the cast metal material below and fracture. The fractured plating then peals off of the cast metal. The cam shaft lobes are then damaged by contact with the abrasive cast material."
    That is the first explanation I have read as to why it is the rocker arms and not the cam and it's hardening.

    Very interesting.

    5W40 is going to do very little to cushion impact of metal to metal on start up. Not sure a 10W40 or even 20W50 would help? I mention this as I see this as the time when it has the least amount of oil or cling on the items.

    As far as timing I have had mine change. It is go/no go so it takes very little for the jig to not fit.

    I also have replace all four exhaust shims as all 4 were tight strait from the factory. I was tight on 2 and the other 2 were close. I set all 4 in the middle range or just tight of middle range. That was from checking at 60 miles, 600 miles, and at 6000 miles. I then changed them as they were tighter using the same gauges same technique etc.

    At 18K everything was spot on.

    Have a 24 K coming in a few I will see how it all looks.
    The above is worth what you paid for it..........
    Lee 2017.5 R 1200 GSW

  4. #334
    Registered User lkraus's Avatar
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    Quote Originally Posted by GIARCG View Post
    Glancing at this thread for the first time and have not read all of it so maybe this has been covered...

    From the few posts that I have read this problem/cause may be similar to what Ducati was dealing with in the early 2000's... and I dealt with on my ST4.

    The problem as described by a vendor of replacement rockers...


    "Q. What is the actual cause of rocker arm failure?

    A. The most common failure "Flaking" ("Peeling") is caused by cracking and separation of the hard plated surface from the base material. The stock arms are cast from metal that is plated in the areas that are contacted by the cam shaft. The plating is a very hard and abrasion resistant material but it is also very brittle. The cast metal is porous, nodular, and relatively soft in comparison to the plating. Under normal operating conditions the cam shaft not only slides over the rocker arms it also impacts the face of the arms on each revolution. The plating is well suited to provide abrasion resistance from the sliding action but due to its brittle nature can not withstand impacts. The cam shaft impacting the surface of the rocker arm causes the plating to indent into the the cast metal material below and fracture. The fractured plating then peals off of the cast metal. The cam shaft lobes are then damaged by contact with the abrasive cast material."
    This is pretty much how I imagine the failed plating could cause the cam wear. But I think "abrasive cast material" base material is only part of the problem. If a bit of plating fractures and flakes off, it could leave a hard, sharp, edge behind, which could act like a chisel to remove material from the cam.

    Wish someone with damaged cams would post pictures of the rocker arm surface.
    Larry
    2006 R1200RT

  5. #335
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    Confirmation of the Ducati problem was found by inspecting the sump screen... pics here:

    https://www.ducati.ms/threads/metal-...25/post-704699

  6. #336
    Registered User LFarling's Avatar
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    Quote Originally Posted by lkraus View Post
    This is pretty much how I imagine the failed plating could cause the cam wear. But I think "abrasive cast material" base material is only part of the problem. If a bit of plating fractures and flakes off, it could leave a hard, sharp, edge behind, which could act like a chisel to remove material from the cam.

    Wish someone with damaged cams would post pictures of the rocker arm surface.
    I agree. We always see the cam but never the rocker arm.

    Also I have seen where others have opened filters and found no metal flakes as the pictures posted. This appears to make mud, not pieces of metal. Of course I am not sure if a dealer is opening the sump to clean it but IMHO they should. But if they did we would never see a picture as BMW would have them shot for sharing a picture of a sump filled with metal
    The above is worth what you paid for it..........
    Lee 2017.5 R 1200 GSW

  7. #337
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    Cam wear

    The Ducati rocker arms are chrome plated against wear. The failures were caused when the improperly applied chrome plating would flake off, ruining both the rocker and the cam. When anyone does an oil change on a early to mid 2000's Ducati Desmoquattro Engine, they should pull the sump screen and check for the tell-tale shiny metal flakes that are a give-away of chrome flaking. Don't think the abnormal wear on the BMW is quite the same.

  8. #338

    BMW Stood Behind It...

    LAST Update: The fine folks at BMW FedEx'ed the parts to Bob's, and the experts at Bob's finished my bike up this evening. Charge to me? Nothing but downtime and a copy of my service records.

    I can't thank Tony Rouse and the Bob's BMW team enough for advocating and working with BMW, and props to BMW for standing behind the bike.

    You can crap on your dealerships all you like, but I'm keeping mine.

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