R1150RT Front Crankshaft seal

Discussion in 'Road Warriors' started by Cpt. Ron, Mar 16, 2013.

  1. Cpt. Ron

    Cpt. Ron Advrider #128

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    OK, so what's the trick to replacing the seal that is on the front of the crankshaft within the alternator bracket? Mine leaks, even after replacement. The manual calls for "pre-shaping", which I'm not doing or not doing right. I'm tired of tearing the RTP down to this level to try to fix this.

    Any advice?
    #1
  2. Cpt. Ron

    Cpt. Ron Advrider #128

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  3. bensgone

    bensgone Been here awhile

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    Pre shape in what way? What year is your rt?
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  4. kraven

    kraven Hegelian Scum

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    You said front crank seal in your op and then posted something about a fix for the rear seal as a solution.

    I think you should take it to someone and pay them for their expertise, ride your bike, and be happy.
    #4
  5. Cpt. Ron

    Cpt. Ron Advrider #128

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    I may be new to these seals, but I won't be paying someone to wrench on my bikes. The parts are costly enough without paying for labor. I would be out riding, but I'm wrenching and posting here, instead.

    Yes, I said front seal. The factory manual I have says that pre-shaping is required before installing the front crankshaft seal (mentioned in the first post). The link I posted demonstrates BMW's oil seals that need to be "pre-shaped" before installation (wasn't an easy find, either). I imagine it's similar to other seals on my bike as well as other BMW's. It also mentions a special tool which is typical for manufacturers.

    I was hoping that someone would: #1 understand what I'm talking about and/or have been here; #2 have a routine or procedure that works for installing the seal correctly.
    #5
  6. k-moe

    k-moe Long timer

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    From reading that Pdf, what they want you to do is bend the lip of the seal toward the inside of the engine case before installing it so that it will press against the shaft once it's installed. I think you can use a bit of thin-walled tubing to make the tool. It will need to have an i.d. that will allow it to slip over the shaft, and an o.d. that isn't so large as to damage the seal. My thought is that you lubricate the tube/tool and place it in the seal from the front so that it bends (pre shapes) the inner lip of the seal (leaving the back of the tube flush with the back of the seal so you don't damage the shaft during installation), then you place the tube/tool on the shaft and drive the seal in, and finally remove the tube.
    Having said that, it seems that the tool is only needed if the shaft that the seal is going on isn't chamfered. If the shaft does have a chamfered end it looks like you can shape the seal with your fingers as you install it onto the shaft.

    This is only a thought, not a description of the factory-approved procedure.

    Alternatively you could go to a bearing house with the old seal and see if they can match it to a more traditional type of oil seal that wouldn't require a special instillation technique.


    Also....try this http://www.bmwmoa.org/forum/showthread.php?66801-Engine-Front-Cover-alternator-mount-Shaft-Seal-reinstall&highlight=alternator+oil+seal+installation
    #6
  7. Cpt. Ron

    Cpt. Ron Advrider #128

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    Replacing the seal is pretty straight forward for anyone who has done something similar. The only difference is pre-shaping the inner seal lip. Why they did this, I don't know. Sure, the seal may last longer than traditional seals in this duty, but if you have to replace it whenever the alternator comes out of the bike, I think the benefit is lost.

    Here you go:

    [​IMG]

    [​IMG]


    The new seal:

    [​IMG]

    [​IMG]


    This is the point where the pdf document I linked above comes in to play. If you don't do this step, the inner lip folds the wrong way during installation, causing leaks. The factory manual doesn't go into detail on this step.

    The new seal after pre-shaping with fingers and some oil:

    [​IMG]


    Wrap some electrical tape over the nose and lubricate with some oil.

    [​IMG]


    The trick is to keep the inner lip of the seal "going the wrong way" when pushing the seal on the crankshaft.

    [​IMG]


    Appropriate seal driver:

    [​IMG]


    Gently and squarely drive it home:

    [​IMG]


    Remove the tape and you're done. Well, you still need to put the rest of the bitch back together....

    [​IMG]
    #7
  8. bensgone

    bensgone Been here awhile

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    Nice pic-write up, thank you!
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  9. Anorak

    Anorak Woolf Barnato

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    I'm recall that the front cover doesn't have to come off to remove the alternator. Remove the ABS assembly.
    #9
  10. Cpt. Ron

    Cpt. Ron Advrider #128

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    I thought of that at the time. That seemed like more work than the way I went (per the manual) due to the multiple brake lines and such. In hindsight, you may have been right......
    #10
  11. Cpt. Ron

    Cpt. Ron Advrider #128

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    Thank you. However, not all (was) well in my garage.....

    it didn't work. Still leaked. I'm better at taking pictures and riding than working on flower-delicate BMW seals.....

    So I went a different route. Stay tuned.
    #11
  12. bensgone

    bensgone Been here awhile

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    Staying tuned! This is my first bmw, 02 1150rt, so you bet I am staying tuned. I bought it on new years day and love it so far but didn't realize the inherant problems this model till later. The abs light is unplugged but the servo still works so that is first, seals and tchain rails after. Please pm me with any info you have for me, thanks!
    #12
  13. Ianuk

    Ianuk Adventurer

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    How did you get on with a different seal, I'm having the same trouble with mine.
    #13
  14. larryboy

    larryboy Chopper Rider

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    How's the knee?


    Here's how I do that type of seal...put it over the snout backwards, it will pre-form it, leave it like that for a day, take it off and install properly as quick as you can. Forming it with your fingers will leave it not quite even at some point and it will leak again. Quality seals come with a form popped into the seal, it keeps it formed until the time the form is removed and the seal installed.
    #14