lubing trans spline and leaking neutral switch

Discussion in 'Airheads' started by LandLeftBehind, Feb 5, 2013.

  1. LandLeftBehind

    LandLeftBehind Been here awhile

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    I finally have shop space to work on my beat up ol' girl so I plan to start things off by doing a throwout/spline lube service and to hopefully fix a leaking neutral switch in the process.

    My questions are a.) can I access the neutral switch without taking the trans off during the spline lube and b.) can I reuse the old neutral switch (which, minus the leaking, works fine) and just apply the jb weld/super glue repair I see discussed on some adv threads and snowbums website?

    Havent done this work before so just trying to prepare myself for the worst :D
    #1
  2. dustdonkey

    dustdonkey Been here awhile

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    a) Yes it's possible.

    Take the rear engine stud out (the one that runs under the tranny) and use a tyre lever to get the spacer between the two frame pipes out.

    Stick it in the freezer for re-assembly.


    b) I glued mine with an epoxy resin and it seems to be sealed.
    #2
  3. LandLeftBehind

    LandLeftBehind Been here awhile

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    Great...Im still not exactly sure of where I need to apply the epoxy, but im sure it will be clear when I get a chance to take things aparts and see it for myself.

    As for the throwout/clutch parts, can I use white lithium to grease them?
    #3
  4. chollo9

    chollo9 Screwed the Pooch

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    You want something more substantial than white lithium, preferably something with moly. I mix up a paste of about 50/50 moly assembly lube and wheel bearing grease. And just put the lube on the trans shaft, not the clutch itself. Overlubing can get squished out and thrown on the plate, which isn't good.
    #4
  5. craydds

    craydds Long timer

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    Probably best to use Honda Moly 60 on the splines. You might not take your trans out, but the idea is to brush on a very LIGHT coat:
    [​IMG]

    Throwout parts get cleaned and greased with a heavy grease such as wheel bearing grease; you can use the Moly 60 on the throwout bolt where it contacts the throwout rod:
    [​IMG]

    Moly 60:
    [​IMG]
    #5
  6. craydds

    craydds Long timer

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    When you get it back together, give this a few shots of a good, heavy grease. I use the Belray Waterproof grease, comes in a tub and in tubes for grease guns (the Honda Moly comes in a small tube for the small grease gun):
    [​IMG]
    #6
  7. craydds

    craydds Long timer

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    Good luck. Sounds like a challenge. Here is another pic for your viewing enjoyment:
    [​IMG]
    #7
  8. disston

    disston ShadeTreeExpert

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    Just because it is possible to lube the splines does not mean that it is the best way to do this job. This is also your first time doing a spline lube? It is good advice, I think, to take the trans out. It will generally be easier to work on stuff and see what is going on. I have done this job many times over the years. I still take the trans out. Did it once by pulling the trans back, once, never again.

    Careful not to over lube the spline. The Honda Moly 60 is the product to use. Grease goes only on the input shaft splines. A light coat as said by others.

    The idea of sealing the neutral switch is that this switch is an Aluminum casting with a plastic internal portion. There are electric terminals in the plastic. Since you are going to try and seal a switch that already leaks you will have to get the part that is leaking CLEAN. The plastic part is not bonded to the Aluminum or electrical contacts part. So a thin epoxy is used to seal this. It may work if you get it clean enough. If you find other threads here on this subject you may see the pictures of riders epoxy work on these switches. Cool stuff by some of the inmates. If you find that thread post the link, I'd like to see those again. Works of art.
    #8
  9. LandLeftBehind

    LandLeftBehind Been here awhile

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    I had read that a light, soft grease was to be used on the throwout parts. Why use a heavier grease with moving parts?

    Awesome pics by the way, now I have a better idea what all that hullaballo about the spacer and whatnot is about (:
    #9
  10. craydds

    craydds Long timer

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    Probably any grease is good, nothing wrong with the "light, soft grease"; the heavy grease is applied in such a thin coat that it has little effect on the moving parts; plus, the heavy grease sticks the parts together as you place them back into the trans. As Chollo said in another thread, most mechanical problems can be solved by CLEANING and LUBING. I agree with disston - it is not hard to take the transmission out, just TIME CONSUMING. You can get at that neutral switch, and inspect, clean, and lube everything more easily. Then, it is a time consuming but easy chore to put it all back together. We can talk you through the steps.
    #10
  11. craydds

    craydds Long timer

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    Disston posted a pic of the throwout mechanism in another thread; we had been discussing similar issues with another inmate; see Charlie's post #22 here http://www.advrider.com/forums/showthread.php?t=860181&page=2
    #11
  12. disston

    disston ShadeTreeExpert

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    A word about grease(s).

    The splines are to be lubed with a high pressure grease. This technical term is a reference to the pressure the splines see. When the clutch is accelerated with the input shaft of the transmission the splines are carrying all the horse power and torque the Airhead engine can produce. Molybdenum is the preferred type of high pressure grease these days, in most applications, I think. The Molybdenum handles the high pressure very well. But eventually it gets washed away or wears away and so it is mixed with a heavy grease to help it stay in place. Over the years there have been many different greases tried for this particular application. None of them have been perfect. Stick around and I'll bet in a couple more years we'll be trying another product, again. Happens every couple of years. But it seems that the Honda Moly 60 lube is the grease of choice for this application currently and so I recommend using this product also.

    The grease used for the assembly of the throw out pieces in the transmission is normally Wheel Bearing Grease. This is being used as an assembly lube. It will be washed away by the gear oil once the transmission is in service. The throw out pieces are lubed by the gear oil in the trans. This grease is only for start up.
    #12
  13. craydds

    craydds Long timer

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    Disston, thanks for the post above. Got me to thinking! I have a few cans of spray CHAIN LUBE for my dirt bikes; high tech stuff, supposed to cling - not fly off, lube well, not affected by water/dirt, etc. I am going to try this on my other Beemers as a SPLINE LUBE. Think of the abuse a dirtbike chain must endure; the input shaft splines are living in heaven compared to a chain. Yes! I have discovered the Holy Grail of spline lube.
    #13
  14. disston

    disston ShadeTreeExpert

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    It might work fine or better or not at all. But really it sounds good to me. Does the label say what's in it?

    Careful to still not over grease the splines. There's always a danger of too much grease can contaminate the clutch disk. Only apply to the input splines, not the clutch disk splines.
    #14
  15. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    get the after market brass one from Hucky's, the OEM will leak in a year or less. Epoxy may or may not work, so take a chance on using it and having it leak.

    I have gone through 2-3 OEM ones, and have had the brass one in for a 1.5 years of leak free operation.
    #15
  16. craydds

    craydds Long timer

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    Thanks for the advice; will get a neutral switch from Hucky's if I ever need one. I would advise LandLeftBehind not to repair an old switch - just get a new one, like One Less says.
    p.s. My neutral switch is original, no leaks! How old is that, 38 years?
    #16
  17. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Do use a high pressure grease! It needs to be something that doesn't squish away under high pressure. It's usually pretty stringy stuff and doesn't clean up easily by wiping with a rag.

    As for the neutral switch - just get the brass one from Motobins. Not expensive and they're not supposed to leak. The new BMW switches seem to not last longer than a year. And since you're pulling the trans, or moving it back, there's no need to pull the rear engine mount tube in the block. I would recommend just pulling the trans rather than only pulling it back.

    Well done finding a place to work on the old girl! She's got a bit more 'character' than this time last year, huh?
    #17
  18. Airhead Wrangler

    Airhead Wrangler Long timer

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    +1 on this. Sliding the trans back doesn't really save you much time at all and guarantees that you won't do a great job of cleaning and lubing the splines. Plus with all the disassembly work you'll need to do, you might as well just do the last step and get it apart so you can get a good luck at everything else inside, not just the splines.
    #18
  19. LandLeftBehind

    LandLeftBehind Been here awhile

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    My main concern with fully removing the transmission is unfastening the drive shaft u-joint. My bike is in my shop space, and Im having trouble visualizing the parts from the fiche, but would it simply be a matter of rolling back the rubber boot and unfastening the special bolts (reversing for reassembly)? If so its probably not as big of a deal as im making it out to be.

    Btw the Honda moly 60 is on its way via mail. Ill be sure to get a switch in the mail and pick up some wheel bearing grease for the throwout parts this week!
    #19
  20. LandLeftBehind

    LandLeftBehind Been here awhile

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    You can say that! :lol3 Sometimes I look at the pictures I took when I first got the bike. :cry
    #20