Page 2 of 2 FirstFirst 12

Thread: Oil Leak BMW R1100s - calling you wrenches

  1. #11
    Join Date
    Mar 2009
    Location
    Phoenix AZ
    Posts
    1,647
    OK had a better look. Hard to see anything with those photos. But if you are inclined to have a peek around here are my recommendations. (I did truthfully stay at a holiday inn express all this week )

    What was the result of the sniff test?? Hypoid gear oil (burnt greasy frog smell) or engine oil (tattooed biker babes thighs after a 20 mile trip on a shovel head type smell)

    1. Check the drive shaft rubber boots, holes?? If there are no holes then after running your lady like white gloves around the bottom of the rubber boot check to see how oily they are. Lots of oil or does it appear to be runoff from elsewhere.
    2. Undo the hose clip and pull the boot back gently ($20 - $30 for that boot from BMW), Is there any oil inside the boot. Lots of oil inside the boot points to the gearbox output seal.
    3. No oil in the boot and you need to start looking further forward. Gearbox drain plug or front of the gearbox and leaking down the joint.
    4. Probably by now you should get the degreaser out and clean it all up. Then give it a little while and see where the oil is coming from.
    5. If you have weepage from the junction of the gearbox and engine you need to go back to the sniff test (remember that one from a lot of postings ago). If it is gearbox oil then you have a front shaft seal issue (not common). If it is engine oil you potentially have a rear main seal problem.
    6. But if it is engine oil have you gone back over the service points (sump/drain plug, oil filter etc) to make sure you didn't have any senior moments during the service.
    7. Either the front gearbox seal or the rear main seal will give your clutch a lube job it didn't ask for so lets hope its not those.


    OK let us know what you find and we can make some more scientific wild arsed guesses (SWAG) and feed you all sorts of advice from our lofty perch in the peanut gallery.

    Now the disclaimer: The closest bike I have to yours turned 50 this year. No oil heads in the garage anymore. I am not a BMW tech (but read the above reference to the Holiday Inn Express). I sold my last oil head a year ago and with the amount of liquid consumption damage my brain has suffered the memory may not be functioning correctly. So what I am saying is I will help you find out what could be the problem. It is up to you to decide what to do about it
    2007 Freightliner Dualcab Ambulance conversion. Check it out here
    FJ75 Landcruiser 6 wheeler (Converting to an AmboCamper)
    1963 BMW /2 with a Ural Sidecar.

  2. #12
    Join Date
    Mar 2009
    Location
    Phoenix AZ
    Posts
    1,647
    Ah sorry about the cross post. Hopefully my description of the smells will help you work out which one it is. Or open your fill plug on the gearbox, stick your little finger in there and compare the scents. Its a bugger I don't have anytime spare this weekend or I would take a run up and have a look. I will be up there in early Sep if you haven't sorted it by then.

    Also you can usually check the gearbox oil level with a finger in the fill hole. Much easier than a rover, although from owning a few series 1 & 2 rovers and a lot of british bikes I would agree with your diagnosis (for rovers anyway). If its not leaking it is definitely empty.
    2007 Freightliner Dualcab Ambulance conversion. Check it out here
    FJ75 Landcruiser 6 wheeler (Converting to an AmboCamper)
    1963 BMW /2 with a Ural Sidecar.

  3. #13
    Join Date
    Apr 2007
    Location
    Prescott, AZ
    Posts
    5,308
    Okay, so I checked the gearbox fluid level. It appears to be quite low indeed. Could be a totally separate issue, I suppose.

    I tried to check inside the boot at the forward end of the driveline, but it's really tucked in there pretty tight on this bike. Hard to access it to check for fluid inside the boot.

    This photo shows where the bulk of the oily residue had collected. It didn't appear to have exited the drain plug as it was clear immediately around the plug and it was sufficiently tight. I assume the oil under the gearbox was just blown forward at riding speeds.

    I also noticed my oil is perhaps .5L low, but post a 3000 mile ride, I've been told that's normal.

    Here's where the bulk of the oily residue was located.
    leak_zps6cb7e9e9.jpg

    I cleaned everything as best I could. I think I'll add oil to the gearbox, top off my engine oil and see if I can better assess where the leak is originating. I'm foolishly contemplating fixing this myself. I'm not a bad wrench, just reluctant.
    Bicycles rule.

  4. #14
    Join Date
    Mar 2009
    Location
    Phoenix AZ
    Posts
    1,647
    When you are filling the gearbox with oil check with your local auto parts place and see if they have any of the UV dye to put in there. Then grab your trusty scorpion chasing UV light and use that to check around to see where it is coming from. If it oil reappears and you can see the UV tracer then it is from the gearbox. If it comes back and no UV tracer then it is engine oil. (alternatively you could use something like Royal Purple oil and just check the color but I am all for simple gadgets). I will PM my email address. Could you send me the photos in higher resolution??
    2007 Freightliner Dualcab Ambulance conversion. Check it out here
    FJ75 Landcruiser 6 wheeler (Converting to an AmboCamper)
    1963 BMW /2 with a Ural Sidecar.

  5. #15
    Join Date
    Apr 2007
    Location
    Prescott, AZ
    Posts
    5,308
    I just topped off the gearbox. It has a 800 ml capacity and I was able to fit 350 ml in there. Definitely low, but it's probably been 4,000 miles since it was last checked.

    My oil engine oil was low by about 300 ml as well, but again, after a 3000 mile trip, I expected that.

    Now to see where the leak is.
    Bicycles rule.

  6. #16
    goodtimes's Avatar
    goodtimes is offline Expedition Portal Moderator Expedition Poseur
    Join Date
    Jul 2005
    Location
    Tucson
    Posts
    5,698
    Quote Originally Posted by Flounder View Post
    It certainly appears to be the transmission output seal. So Brian, you're thinking this will be a spendy fix, right?
    It's a BMW, its going to be expensive. Just sign the title over to me, I'll remove the offending bike (leak and all) free of charge. Then you'll have room for a new *something*.



    (yea - I have no idea how much it will cost or how hard it will be to fix).
    "Life is meant to be enjoyed, not endured" ~someone

  7. #17
    Join Date
    Mar 2009
    Location
    Phoenix AZ
    Posts
    1,647
    Any progress??
    2007 Freightliner Dualcab Ambulance conversion. Check it out here
    FJ75 Landcruiser 6 wheeler (Converting to an AmboCamper)
    1963 BMW /2 with a Ural Sidecar.

  8. #18
    Join Date
    Apr 2007
    Location
    Prescott, AZ
    Posts
    5,308
    I topped off the oil in the gearbox as well as the engine, which was down just a tad. I checked the final drive levels, which looked okay. I've ridden it around a tad and nada. Haven't seen nary a drop on anything. I think it's mocking me. Or, it overheard us talking about going to Brian's house and it decided to shape up.
    Bicycles rule.

  9. #19
    Join Date
    Sep 2017
    Location
    Maine, USA
    Posts
    1
    I've got the same R1100S with the identical leak going on. I'm going to clean it all up really well and keep an eye on it to see if I can determine the source. In the mean time, Chris, did you run into any further trouble with yours?

Page 2 of 2 FirstFirst 12

Posting Permissions

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