New Airhead Project

Discussion in 'Airheads' started by guywithchickens, Oct 10, 2017.

  1. fxray

    fxray Long timer

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    FWIW, I posted a bunch of pictures when I disassembled my final drive unit. My build thread is quite long. but you could drop in on it HERE and scroll through to see what is inside the nose of that final drive unit. If you don't care to read through all my brilliant prose, skip to the next relevant part of the story HERE.

    Below is a quote from Snowbum: click here and scroll down to section 5. I disagree with him about the Hylomar. I don't think it works well in this application. Here is what he said there on his page:

    Section 5. Leaky driveshaft drain plug:
    Usually this has happened due to the threads being stripped from over-tightening. If the threads are not repaired at exactly 90°, the plug does not go in straight. You CAN NOT repair the drain plug threads properly with the drive on the bike, NOR without disassembling some of the nose area of the drive, due to an internal threaded ring that has been discussed earlier in this article, that you probably won't see any of this from the fully assembled rear drive ...but you WILL damage things if you just try to re-tap the hole, or, worse, drill and install a Helicoil. The proper fix is to remove the rear drive and disassemble at the nose, and install a Helicoil. You need two special tools mentioned considerably above, heat, and a new seal (and on later models, a new plastic washer as noted earlier). I use HYLOMAR on the threads of the threaded ring. Hylomar works well on those threads. You do NOT need to do re-shimming.​
    #41
  2. guywithchickens

    guywithchickens Been here awhile

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    Good info, thanks. Also, outstanding write-up. I'm guessing the reason I have to remove all the parts is that the seal carrier ring would prevent a tap from going deep enough, correct?

    Based on a quick read, I'll need a tool to remove the seal carrier ring. Snowbum says it's possible to "bungee the nose to the wheel" to react the torque to remove the nut on the input gear. Any pics on how to do this?

    I figure if I'm going in to the nose, might as well replace the two seals. Drive shaft didn't really have much fluid in it, might be leaking into final drive?
    #42
  3. guywithchickens

    guywithchickens Been here awhile

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    Tank progress! Four days of vinegar so far. I drained, filtered, and put the vinegar back in. POR-15 kit is on its way.

    IMG_1124.JPG
    #43
  4. fxray

    fxray Long timer

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    Yes, that's correct. You also need to carefully set up and run your drill and tap through the housing perpendicular to the seal washer seat on the housing. Otherwise, the head of the drain plug would be canted at an angle and the plug would leak. Snowbum said on his site that there are oversize plugs and seal washers available, in case you don't want to use a Helicoil or a TIME-SERT insert, but I don't know where you would source one. Maybe search on here.

    I suppose that could work, but it sounds loosey-goosey-here-hold-my-beer-and-watch-this to me. :lol3 :lol3

    I bought the tools from Dan at Cycle Works, and they did the job quite well. People have been posting that he has been slow to respond to tool orders lately, but I think he is back at it. If you can get the tools, they are high quality and they work well. I listed the ones I used in that earlier link above.

    Your tank is looking good. I have one at about the same stage right now myself.
    #44
  5. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

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    You put the rear drive on the rear wheel to torque the input shaft nut, but I use a ratcheting tie down strap through the spokes and around the "nose" (front of rear drive) to hold them together...
    #45
  6. guywithchickens

    guywithchickens Been here awhile

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    Aha! I get it now...
    #46
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  7. guywithchickens

    guywithchickens Been here awhile

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    Close ups of the offending area. Replacement seals for the nose are on their way. Going to diassemble today. Helicoil kit is on the way too.

    Looking at the second picture again, that hole is ugly. Going to need to get a nice perpendicular hole and clean up the sealing surface. I knew I was doing this damage, but I had no other ideas on how to remove the plug. I'll take comfort in the fact that I'm not the one that tightened it down too much originally!
    IMG_1125.JPG IMG_1126.JPG
    #47
  8. fxray

    fxray Long timer

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    As scarred up as the seal face is, it would be a very good idea to lightly run a spotface tool on it. If that is done on the same setup as the drill & tap operation, the threaded hole will be perpendicular to the seal surface. See if you can find a spotface tool with a pilot suitable for the hole size that you are going to drill.
    #48
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  9. guywithchickens

    guywithchickens Been here awhile

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    Getting the nut and seal carrier ring off was surprisingly easy (at least compared to getting the front sprocket nut off my V-Strom).

    Here's a pic of the drive strapped to the wheel. Ratchet strap is the load bearing feature, bungee just keeps the system slightly preloaded. I also put a long bolt though the wheel and drive to hold it together. No heat, 24mm socket, 24" breaker bar, removal was easy.

    IMG_1128.JPG

    Took off the straps, heated the housing with my torch, repeatedly checking temp with my IR gun. Got housing to ~220F. Inserted 2.375" spindle socket and seal carrier came out with minimal load (maybe 10-20 ft-lb?). Spindle socket is P/N W1271 from Performance Tool (O'Reilly's). I'll work on getting it properly jigged in my drill press, then still waiting for the Helicoil kit to arrive. Thanks to all for the great info!

    IMG_1130.JPG
    #49
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  10. guywithchickens

    guywithchickens Been here awhile

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    Started disassembling the carbs. Two questions:

    1. Any trick to removing the float bowl? Feels really stuck, but I don't want to booger it up with pliers/vice/etc.
    2. Can't get the tiny brass screw out of the throttle plate. I'm afraid i'm going to strip it completely. Tips?

    IMG_1135.JPG
    #50
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  11. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    heat on the brass screw possible thread lock on it plus it might be peened on the back side and the throttle shaft might have to be replaced anyway.
    #51
  12. guywithchickens

    guywithchickens Been here awhile

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    Solutions:

    1. Block of wood on the raised fins, slight hammer taps
    2. Had to drill then use a screw extractor. Threads look OK, but I'll need another screw.

    Carb parts are now soaking in Pine Sol.
    #52
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  13. fxray

    fxray Long timer

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    Here's a tip. The brass standpipes in the float bowls tend to split up one side. The split may be so fine that it is tough to see without a magnifying glass. A good way to check these is to set the bowl on a flat surface, and then pour gas into the bowl. The bowl should hold gasoline with no leaks when the fuel level is just below the very top of the standpipe. If there is a split, you will see gas running out the bottom of the standpipe where it is pressed into the bowl. Should there be a leak, it is easily repairable. Click HERE for more info.
    #53
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  14. cycleman2

    cycleman2 Long timer

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    Float bowls. They sometimes stick on the gasket, so once you have the spring clip open, tap the sides of the bowl gently with a screwdriver/rubber mallet. Be gently.

    Butterflies. These are peened on the backside. Get a small magnifying glass and you can see the threads. The way to remove these screws is to file the threads until the peened threads ( usually the last one ) is removed. Then the screw will turn out. The way to test is that if you are encountering resistance on screwing the screw out, stop put it back in and file some more. The screw is steel and the threads are brass, so very easy to damage them and then you have to get new shafts. Be aware when you put them back together the butterfly will only work one way. I usually just scribe a small scratch on the top front of the butterfly to assist in identifying their orientation. My guess is if you didn't file the screw thread you will need new throttle shafts. Those threads are too soft to repair. Them & the screws can be had from a BMW dealer and there are some aftermarket sellers out there as well. When you put everything back to get just use some blue locktite on the small screws. You can certainly peen them if you want, but most of us don't.
    #54
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  15. guywithchickens

    guywithchickens Been here awhile

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    Rusty tank evolution...

    Tank History.PNG

    Vinegar included 20 3/8" nuts and lots of shaking every time I went to the basement. I also rinsed it 1000 times (at least it felt like it) until no debris came out. POR-15 is still drying but looks pretty good so far.
    #55
  16. guywithchickens

    guywithchickens Been here awhile

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    Thanks. Float bowls turned out to be pretty easy. Those little brass screws were a PITA. I had a hard time just getting them started. Probably going to need new shafts.

    Update: Bit the bullet and ordered new screws and throttle shafts. Not worth the $$ to try to mess with it.
    #56
  17. guywithchickens

    guywithchickens Been here awhile

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    Going to drill/tap/helicoil the final drive drain today.

    Question: How can I clean the outside of the final drive? I don't think I should submerse it in my degreaser. I suppose I can spray and wipe. Any orifices or features I need to protect/avoid?
    #57
  18. fxray

    fxray Long timer

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    ^^^ I wrote up my alloy cleaning notes HERE.

    It would be a very bad idea to submerse it in solvent unless you are going to completely disassemble it. There are two weep holes and a vent in your final drive housing. For some pictures of those weep holes and where they go, look HERE. Scroll down a few pictures till you see the one with the seal pick pointing at the weep hole near the axle opening.
    #58
  19. guywithchickens

    guywithchickens Been here awhile

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    Perfect! Thanks. I need to start checking your build thread before I ask. I’ll just follow your lead...


    Sent from my iPhone using Tapatalk
    #59
  20. guywithchickens

    guywithchickens Been here awhile

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    Helicoil complete. Very simply process. Now for final drive cleaning, then reinstall the bits in the nose.

    IMG_1159.JPG
    #60
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