Engine Jacks

Discussion in 'Airheads' started by brocktoon, Jul 10, 2013.

  1. brocktoon

    brocktoon Been here awhile

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    Probably a pretty simple question: what are you guys using as engine lifts for our airheads? I need to pull the engine up and forward to get enough room to get the gearbox out. Gotta figure out why it's leaking *again*. Last time I lifted the engine to get the gearbox out I used a car jack with some wood for support. It ended up slipping and the engine landed on the pushrod tubes. Nearly gave me a heart attack.

    Anyone know of an engine jack that fits "just right"?
    #1
  2. chasbmw

    chasbmw Long timer

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    for a twin shock or monoshock, leave the engine where it is and loosen off the swinging arm, pull the swinging arm back and chock it in place, this should give you more than enough working space.

    when im removing an engine, I use an ordinary trolley jack, with a piece of wood between the jack and the engine. i put the engine in place and then carefully lower it into position.
    #2
  3. AirbusScott

    AirbusScott Adventurer

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    I'm just a FNG (%#+€£% new guy) here but...

    IDK, which airhead your working on but on my '78 R100S pulling the trans was easy and no jack is required. The driveshaft bolts are the hardest part and as long as you have the "new" style bolts no parts needed.

    As far as a jack I would guess a transmission jack would work well.


    #3
  4. brocktoon

    brocktoon Been here awhile

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    Ok, makes sense. The Clymer manual says to lift the engine up and forward to get enough room to pull the transmission up and out. Maybe pulling the swing arm back is easier and safer.

    I'm working on a LWB '73 R75/5
    #4
  5. Airhead Wrangler

    Airhead Wrangler Long timer Supporter

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    That's how I've always done it. I've never tried lifting the engine to remove the trans, but it sounds a lot tougher.
    #5
  6. Plaka

    Plaka Brevis illi vita est

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    Remove the bolts that connect the driveshaft to the transmission. leave the boot clamps slack, inspect the boot and know the deal with replacing the bolts and the bolt lengths. I index the mating flanges so they go back the way they were. Optional.

    Remove the seat.

    Compress the clutch lever on rear of tranny and pop the cable off.

    Remove 4 bolts that connect the rear subframe to the main frame.

    Unplug the rear harness, under the upper left subframe rail back of the grab handle or thereabouts.

    Remove the swingarm pivot pin locknuts and pins.

    Move the swingarm/subframe/driveshaft and all rearward a couple inches. Rear wheel remains in and supports things.

    Remove air cleaner.

    Unbolt and remove tranny. It moves 1" to the rear to disengage the clutch splines and lifts out.

    You may or may not have to fool with the battery box. It's a good time to take it out, de-rust and paint.

    When the tranny is out, do not bang the eye that holds the clutch cable sleeve. It is fragile and the transmission heavy. Tricky to repair.


    Depending on where the oil is dripping out of the tranny, the repair may not require removal. The thing has 6 holes in it that seal oil. (if I counted right). Only the front seal requires removal unless you have stripped threads somewhere that require machine work.
    #6
  7. ME 109

    ME 109 Long timer

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    brocktoon, your post suggests that the tranny is leaking. Is it the tranny, or the engine that is leaking?
    #7
  8. darklight79

    darklight79 drink it , ride it , nail it

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    Theres a guy in uk claims 15 mins to pull trans requires pulling a trans stud remove swing bolts push swing back leave wheel on trans back a lil then sideways dont move the engine
    #8
  9. brocktoon

    brocktoon Been here awhile

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    It's definitely the tranny leaking. It's gearbox oil. The leak appears to be coming from where the case mates with the rear cover, at the gasket. Oil forms at the two bottom bolts and drips from there. Below is a picture of where the drips seem to be coming from, circled in red.

    NB: that's not my picture and not my gearbox. It's not even a 4-speed. It's just to give a rough idea of where the leak seems to be coming from.

    About a year ago I pulled the gearbox apart myself for a gearbox tech day. I replaced all seals and bearings and put it back together. The bike was not running when I purchased it, so I can't say for certain whether it had the leak before I pulled it apart. After installing it and filling it with oil I noticed the leak. I tried heating the rear cover and gently tapping to see if it wasn't seated properly and re-torqued the nuts to spec. No joy.

    I took it to my neighbor Brent at Brent's Motor Works and he inspected the mating surfaces, put on a clean and dry gasked, and re-shimmed it to make sure overshimming wasn't the issue. No joy.

    I'm running out of ideas. My final guess before scrapping it is that the rear cover got warped when I was pulling it apart. I picked up a new rear cover from eBay. I'm going to try swapping it with the old cover and see if that fixes it. If not, I'll probably try a whole new case. I have all the tools, except a depth mic and a shim plate for re-shimming.

    [​IMG]
    #9
  10. ME 109

    ME 109 Long timer

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    Well you've tried a new gasket, so that leaves two things, as you've said. Warped cover or damaged/ case. I'm sure you would have thoroughly inspected the case for damage.
    Try lapping the cover on a sheet of glass, that should reveal fairly quickly if the problem is the cover.

    Alternatively some cylinder base sealant (three bond, yamabond) 'should' solve the problem.
    Check the cover for cracks. If there is a crack, it could be very small and difficult to see.
    #10
  11. bikerfish

    bikerfish flyfishandride

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    had a guy at a rally snap a shift spring, a buddy and I had his tranny out in about 20-25 minutes, including beer breaks, we simply picked a side and went to work. Guy at the rally had a workshop trailer set up, had a spring, replaced it while we had dinner, then it went back in the bike, that might of took an hour, many more beer breaks! next morning the guy rode the bike home with no troubles. heck, we even greased the splines!!
    yep, we slid the swingarm back, I always carry the socket to fit the swingarm nuts.
    #11
  12. brocktoon

    brocktoon Been here awhile

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    I thought about trying a very, very thin amount of cylinder base sealant before I go to the hassle of swapping covers, re-shimming, etc. Anyone ever done this? I've certainly never read about it before. Would it affect the shimming?

    Geez, all you guys that can have the transmission out in 15 minutes need to come over to my house this weekend. Beer breaks are on me. :evil
    #12
  13. airsmith

    airsmith airhead wrench?

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    oil can migrate along the gasket, have you done the clean everything very well , dust with powder (foot powder spray works well) run the bike and check the entire area,, (the engine sucking air can pull oil up the center top bolt and it finds the gasket seam and travels to the lowest point) double check the cover alignment pins and their sockets for proper depth and fit..
    #13
  14. ME 109

    ME 109 Long timer

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    45 minutes on the floor out of my RS.

    Sealant wouldn't affect shimming. Only a very thin smear on housing and cover, and only say the bottom half where the problem is.

    Where the hell's SS anyway? He's a sealant bloke.

    Anyone receive a leave of absence form from him? :deal
    #14
  15. Plaka

    Plaka Brevis illi vita est

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    Make very, very sure your breather bolt is clear.

    If the cover is so warped it won't seal, then what you think you are getting for your shimming might not be what you are actually getting. So evaluating cover flatness would be next. Ditto case rim flatness. One game is to remove the gasket, clean things up, then put a gasket thickness shim washer (mic. the outgoing gasket) at each of the bolts, put cover on and torque lightly, then go around and check the gap with feeler gauges.

    When I had my 4 speed gone through by a pro, it came back with ample evidence of sealant at the rear cover. Something brown. So the guy wasn't the neatest with the sealant, his tranny work is unquestionable. If he's using a sealant, he knows something. For myself, when in doubt, I glue the crap out of everything. the Ultra- series silicones work very well and can be used a number of ways---on very clean metal for adhesion or on oiled/waxed/silicone greased metal for a non-adhering gasket. There are also games that involve assembling the parts on the wet silicone, barely tightening them. Allowing the silicone to set overnight and then torquing fully. This works very well on rocker covers. For your application you need to go super thin so I would use a sealant on a clean surface and plan on it adhering.
    #15
  16. ME 109

    ME 109 Long timer

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    Oh, yeah, my 45 minutes included taking the tranny out of the wrong bike first. :1drink
    #16
  17. airsmith

    airsmith airhead wrench?

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    yes, the first question should have been is the vent bolt a vent bolt or a bolt..
    #17
  18. brocktoon

    brocktoon Been here awhile

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    The bolt that holds the speedo cable in place? It's definitely a vent bolt. I cleaned it with a needle and some dental floss a couple of months ago when diagnosing another issue.
    #18
  19. villageidiot

    villageidiot Long timer Supporter

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    Permatex ultra grey is your friend on cases/cover sealing surfaces.

    I've also had good luck with (all I'm allowed to use at work) permatex super 300 brush on. I like to cut it with a bit of thinner, and it goes on smooth, and thin. Use it on all paper gaskets at the shop (vintage mercedes)
    #19
  20. brittrunyon

    brittrunyon 1992 R 100 GS

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    Wondering.................what do your thin it with? :ear
    #20