Refitting Swing Arm

[Adrian]

Once again I have a small problem - fitting the Pivot Pin for the Swing Arm - as you can see from the pictures it appears to be sticking out from the frame about 2 thread pitches. To get to this point I needed a lots of strength with the allan key - I can't remember if this was normal the last time I did this about 15 years ago. Or what it was like when I pulled it apart.
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The dust caps fit okay but if the Pin is further out by only 3 thread pitches it won't fit. I feel this isn't right as you see it. Any advice thanks ....... Adrian
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BREAKING NEWS ------- I have just put a Vernier Caliper across the threads just before the unthreaded section of the Pin. Also inside the back of the threaded section on the frame. The Pin is too large to go thru the frame - but I have managed to free up the threads so that the Pin now sits just inside the recess.
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DISCUSS lol lol

[georgesgiralt]

Ah ?
I would check that the bearings are set properly onto the swing arm on both sides. (remove the inner race, and check that the outer race is seating properly on the recess.). On the right hand side there is a metal shim used to seal the hole in order for the grease not to fill the tube. Check if it is seated properly and not blocking the outer race to seat.
Then, I would check if the other end of the swing arm is installed properly and if the play between the swing arm and the frame is equal on both  side.
If yes, and one pin is still protruding too much, I'm puzzled...

[Adrian]

Hi George - the problem I have is the Pin not screwing into the frame past the point that you see. The bike is completely stripped at the moment as I'm beginning the process of reassembly of the frame and running parts . I have been checking the threads around the frame to make sure they still work okay after Powder Coating. These two threads are the only ones to give me problems -
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I assume that the Pin should screw completely thru the frame and not meet any resistance at all - or at least screw in easily to the point where it sits inside the frame.
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Its a bugger :-)

[montmil]

Been following this topic of yours on the Airhead Beemers site. Good advice you've received there regarding the use of a tap to clean the powder coat residue and assorted gunk from the swing arm threads. Sure don't want to force the pins and booger up threads. Good to see your '84 coming together.

[georgesgiralt]

Well, there is some powder coating on the threads.
DO NOT use the pin to clean this coating. It will damage the threads on the pin.
Instead buy a thread  file (a square metal rod having "threads" of different pitch onto each face. )
And use it to slowly rub the powder coat from the thread.
Use as little force as possible and be careful because you do not want to remove chips of coating which would be place for rust attack...

[Adrian]

Thanks Montmil - I have now put a Vernier across the threads at the non threaded end of the Pin - it seems the Pin is too large to go all the way thru although I have managed to get the Pin just inside the recess area by wire brushing (dremel) the threads - is it possible the Pin is too large to go thru? I seem to remember this from he last time I did the bearings - about 15 years ago when I had the same problem - or so my memory is telling me.

[Bob_Roller]

Swap the pins and see what result you get, it will narrow it down to either the threads, or the pin .

[Adrian]

Hi again. Here's the thing. I can now screw both of the pins into the frame on both sides. They screw in just far enough to fit within the recess and clear the frame. Then they are too tight to screw in any more.
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When screwing them in from the inner side they both ~ in either thread ~ only screw in about a turn or so.
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The threads are clean and on the vernier the threads see to I fat to fit through completely. So it's,clear that the pins are not designed to screw all the way thru.
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I now remember this from the last time I did this work some 20 years ago..
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It seems that this is how it is for this frame :-)

[Bob_Roller]

I just checked all 3 of my R65's and the end of the pins are about 10 mm below the metal that the plastic cap fits on to .

[Adrian]

Thanks for that Bob. My pins are definitely too fat to screw thru the frame beyond where they sit after tightening. They are maybe 2 mil inside the recess. Perhaps the frame is different on this 1984 model like it is for the race cups area of the steering bearings.
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That's the only explanation I can think off for the differences. :-P

[Adrian]

Okay I bit the bullet - as it were. I visited my local Tool Emporium today and have ordered a Tap. Should have it by the end of next week. Hopefully this will fix the problem and I can move on :-)

[Tony Smith]

Okay I bit the bullet - as it were. I visited my local Tool Emporium today and have ordered a Tap. Should have it by the end of next week. Hopefully this will fix the problem and I can move on :-)

Shudder!
Cancel that order and buy a couple of bolts. Then using your hacksaw cut a number of grooves endwise on the bolts - if your hands are steady and your blade sharp you may be even able to cut a couple of "V" channels into the threads of the bolt. Congratulations you have just created a thread cleaning bolt, Give the threads you have just cut a quick cleanup with a thread file and then thread into the frame - take it just past the point where it gets tight and then undo - clean the threads with a wire bush and repeat.

Learned this trick to clean out crankshaft pulley bolt threads on VWs, Three or four bolts will cost you a fraction of what a tap will cost - and you probably got the wrong tap anyway, did you order a lead, intermediate or bottoming tap? You should have ordered bottoming as it is the only one that will correctly fully form (well reform) the threads at the extreme end of the hole.

[Adrian]

Hi Tony - I bought an intermediate tap as the thread has a clear exit point. This was recommended by the tool guy. I looked at a thread cleaning file but they are nearly $60 to buy whereas the Tap is only $30. I have been cleaning out the threads with my Dremel and very small rotary wire brushes which helped a lot but of course aren't cleaning the threads out fully.
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So I'm just following the advice I have been given on other forums. I know that I must be very careful using the tap and turn only a little at a time when it meets resistance. I will try it first on the locking nut to make sure that the tap is properly made. It's really much cheaper to buy a new nut if it all goes pear shaped.
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I have managed to clean out the first half of the threads allowing the Pin to screw in by hand very easily but then at this point it tarts to get stiff and then the pin needs an Allen key to get it to it stopping point which is about 2 mm inside the recess. Every one tells me that the pin should screw thru the threads without any resistance so of course that's the target.
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I'm still confused as the Vernier clearly shows that the exit of the threads is slightly smaller than the threaded section of the pin nearest the plain part of the shaft. In the middle of the threaded section of the pin it is considerably fatter than the exit point. Is it possible that these 1984 twin shock R65 models were slightly different to other R65s???
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I haven't found any photos in either the  Clymer or Haines manuals showing the depth of the Pin so I have nothing to guide me.  Anyone out there like to take a picture of the pin in situ on their bike for me? So I can see how deep the pin sits inside the recess. I would appreciate this a lot --- thanks
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I took a thousand photos of the bike as a took it apart but not one showing the pin - :-(

[Barry]

I would always try Tony's bolt method first if only because taps can sometimes cut oversize and you end up with a slack thread.

[Adrian]

Hi Barry I will try to buy a couple of M20 x 1.5 bolt too at my local mega hardware store - Its too late for the Tap as it was ordered specially and its paid for now. I can only go by the advice I get given - not being an expert. Some guys have gone down the Tap route and said they have no problems. I guess its all about trying everything and hoping something works well. I'm still confused as to how the Pin is obviously fatter than the exit point on the thread though.