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Starter Clutch Replacement

Discussion in 'XJ Technical Chat' started by TheCrazyGnat, Mar 22, 2016.

  1. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    Look at photos of other crankshafts. They do not have localized discoloration unless they were overheated. The whole crank gets heat treated in a big oven, not with localized application of heat.
     
  2. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    yes.
     
  3. Polock

    Polock Well-Known Member

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    ok, i did. now what
    [​IMG]
     
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  4. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    What would cause that kind of "over"-heating (discoloration) effect in just that one area?

    I've never noticed it before (but I don't handle a lot of cranks) but I guess it is somewhat common...........
     
  5. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    Polock, I did see several of them that had similar bluing to mine, I just assumed that they were bad as well. There are more of them that don't have that discoloration, so it seems that one of the two is wrong, and I assumed it was the blue ones. I looked around and didn't really see much as to whether or not it is actually bad. I think that if it was just the web, or just the web and sprocket,I might be less concerned. But the fact that the shaft itself is discolored kind of clinches it for me. I'm no mechanic, and I don't have much experience with this stuff, so I rely on the experience of those on this forum. I looked up the temperature that the rod would need to get to in order to change to blue (assuming the rod is steel) and it is around 590 degrees Fahrenheit. Do we know how got these things normally run? Once again, no idea really, but that seems on the high end. I want to think it would be ok, because I really don't want to dig in to the top end as well, but I don't knew if that is worth the risk. Would you run with it?
     
  6. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    OK. I looked at photos of a NOS crank for a 750.

    [​IMG]

    I see bluing.
    I am wrong about the crank.
    I do still reccomend that the #2 main bearing (and likely its mate) should be replaced.

    Now....how does a poor amn come up with $300 to buy a NOS crankshaft.....
     
    Last edited: Apr 15, 2016
  7. Polock

    Polock Well-Known Member

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    i wouldn't think twice about using it.
    they probably use induction heating there to harden the teeth on those sprockets for wear purposes. and some heat leaks over to that web.
    if it got to 590 deg while it was running, wouldn't oil be burnt on it? not all nice and shiney blue color
    i don't think i've ever read about a broken crank here
    here's a good bearing and a really shot bad bad bearing, if yours look even a tiny little bit like the bad ones replace it
    http://www.dansmc.com/bush_plain_bearings.htm
     
  8. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    Thanks, k-moe and Polock! I figure on replacing at least number 2, probably a few more. Am i right in assuming I'll have to remove the cam chain to lift the crankshaft up enough to check, or is there a way to get enough play in it somehow? Maybe just removing the tensioner?
     
  9. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    You will have to remove either the cams, or break and replace the cam chain with a new one. The crankshaft accounts for almost a third of the weight of the engine. Just lifting it up a bit to sneak a bearing shell out isn't going to happen.
     
  10. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    Would someone be able to verify what the part attached is? I believe it is the intermediate idler gear. It looks to me like it should probably be replaced, any thoughts there?
     

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  11. Polock

    Polock Well-Known Member

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    what seems to be wrong with it?
     
  12. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    It looks like the 3 billy's that were loose on the starter clutch really tore it up. Maybe the picture below is a little better. The difference in color between the front of the sprocket and the back makes me think a layer of metal got eaten away or something. The front had that flat brown color, while the back has the shiny chopper color around the teeth and then the silver color underneath. The back just seems chewed up too, the pictures aren't quite capturing it. Should I maybe just try to smooth it out if I can and call it a day?
     

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  13. Polock

    Polock Well-Known Member

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    The surface that the rollers ride on is the important part. I've done two of them and neither one was perfect but after new springs and rollers they worked fine.
    Look at the part the three springs go into for cracks.
    If you want to hit the teeth with a wire brush, ok but don't get any more aggressive than that
     
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  14. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    Run it. It's fine.
     
  15. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    Awesome, will do, thanks!
     
  16. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    OK, finally got the camshafts out. I was looking at the chain guides for the camshafts and was wondering if I should consider replacing the one on the intake side. The other side looks like it has plastic still on it, but this one appears to be down to metal. I am not sure if that is normal or not. Any thoughts?
     

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  17. Jetfixer

    Jetfixer Well-Known Member

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    Replace them you are this far into it
     
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  18. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    It's been a while since my last update, things have been busy, but I just finished my final paper for my current class. While I have a little bit of free time I am trying to get back on track and I got new main journal bearings all around (found them for under $10 apiece new!). Looking at the service manual, it says to apply molybdenum disulfide to the connecting rod bolts before re-installation. I don't have any pure moly, but I do have the following two products, would either of those be sufficient?
    [​IMG]
    and
    [​IMG]
    Valvoline's Synthetic Grease - Formulated to provide superior high and low temperature protection. SynPower Synthetic Grease is an excellent heavy-duty and multi-purpose automotive and industrial extreme-pressure grease. SynPower is formulated with a lithium complex thickened in a synthetic base oil, moly and other premium additives to provide superior protection from high loads and extreme temperatures.

    Also, is the above Valvoline product good for re packing the rear wheel?
     
  19. Polock

    Polock Well-Known Member

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    that Valvoline is what i use, seems to be good stuff
     
  20. TheCrazyGnat

    TheCrazyGnat Well-Known Member

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    Ok, engine is pretty much ready to be put back together, I just want to get a set of oil seals yet so I have replaced all the rubber and plastic parts. In the bottom end.

    This week was spent bleeding the brakes, I got new stainless lines and pads from Len. Man, that was a bear! I just started tearing into the carbs last night, and I've got a question already: the float needle seat on carb 1 (the only one I've gotten into so far) doesn't have a gauze screen on it, is that an issue? I have Rick's carb write up, the church of clean, Haynes and FSM , it looks like some don't have them, but Haynes has a picture of the seat with gauze.

    I wanted to do the carbs before putting the entire back together so I can just do 1 more big order. I assume that, just by virtue of having started doing this, I should replace the float bowl gaskets? They look pretty well attached, so I may have to do some more scraping (as if I didn't get my fill of that with the engine covers etc.). I'm going to do the throttle shaft seals as well. I'm going to get new hardware too since almost all of the screws are deforming in some way as I remove them. Pilot and main jets too, unfortunately, I almost got a piece of brass in my eye when a chunk of the head came off. Yee haw.
     

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