Top Yoke and Forks Fused!

[Topdad]

Fido , you're right , i've now got the same top nut  via george Prew and his excellent damping kit for the A10  which I 'd recommend to anyone ,I found that with the 8" brake working well the forks dipped and bottomed out to easily sorted ,with these fitted no probs  and such good quality that after 6 yrs still as good as the day they were fitted , only looked at 'em on Sunday. cheers BobH.

[Jules]

OK I've got it now thanks for the extra clearing up/understanding - I have been trial assembling my front end so far so haven't actually fitted the shrouds, so now I see the dilemma to come!
There's a good post back some time ago about how to makeup those in fork dampers too btw. I've made some up but have yet to fit them, and found A65 top nuts to have the same thread but with an inner tapped boss for the rod.........

[Jes-can]

So I was able to get the left fork out without too much trouble using a hammer and putting the top nut in and giving it a few hard taps. The right side though is not budging! If the headlight shroud sleeve wasn't there you could at least try twisting the fork itself, but  obviously can't do that. Bugger! At this point the top nut and fork threads are starting to get damaged, so not sure how much more I do it without ruining and having to replace the fork.

[duTch]

Jesse,
     I hope you're using a Rawhide or rubber/ lead/copper mallet or a drift or something in between, not just banging straight on with a hammer-circumstances permitting??
  Also I'm sure you've loaded it with inox or penetrine or yield or something??
     I've found in the past that sitting back with a simple cup of tea helps??    -serious!!
 cheers duTch

[Jes-can]

Went through two cups of tea yes! I have a rubber mallet, but haven't added anything to aid with loosening. I'll pick something up today. After the second cup I walked away from it and decided it would be best to have another go at it today.

[Greybeard]

Heat is great for loosening things. Could you apply a flame from a plumbers blowtorch to the taper area?

Neil Ives

[Jules]

Jesse it sounds like its well stuck in, like a ball joint taper on a car. So a couple of thoughts
 1. maybe you should make up an adaptor like Topdad suggests by turning off the hex of the top nut and fitting a large threaded bolt into it, then you can screw it right down and use all the thread length engagement in your leg ilo just the top few.
2. on car ball joints you have a tool that (trys to) expand the joint and puts it into tension, then you hit the side and top to vibrate the taper and the residual tension "pops" the joint - can you get a small jack between the upper and lower yokes to create the tension, then give it a whack?
3. the soaking with penetrating oil needs to happen at least o'night, a couple of cups of tea wouldn't be enough for that trick to work I dont think 
good luck.........

[duTch]

The cups of tea were in the past-but did work then, since then I've grown down and moved on to better bevvies, but don't tell anyone

Also the mallet is a bit soft, but just creating a diversion from the angle grinder 

[Topdad]

Good morning Jesse, you must be pretty p****d off by now , seems you've got an awkward one!! mind you ,probably, once this is resolved everything else will seem a doddle. The use of my contraption won't help with this it's only for reassembley. The other idea idea def heat , we used to call it the silent hammer ,if you haven't any other source buy a small butane torch any hardware shop DIY place will have 'em nothing fancy unless you can see a need for it ,I've had one for 10 yrs only needed 3 -4 times but really useful! Obviously make sure nothing flammable nearby ,bike and in the area around and then after making surre everything is loose on the yokes and that the bottom one has the wedge in it mentioned earlier to ease it ,keep the old nut in screwed in just so theres one/two threads above the yoke top and then heat the top yoke up to has hot has you can get it and then give it a solid smack with a lump hammer , I'm not into butchery but unless someone can think of a more gental way forward ,at this point something drastic needs to be done . Obviously if it moves down to the top yoke undo further and continue but only using mimimum force. If no movement and it's not looking like its moved at all i'd redo the heat try again or then revaluate what you are working with. For instance whats the other side of the top yoke like if it looks damaged is it worth worrying about ,at least there are fine second hand ones around and they don't cost the earth . A thought just occured and someone more knowledgeable than me (not difficult ) may be able to confirm, if you could strip the fork leg down and remove it from the outerleg, maybe you could the just take the stanchion off through the bottom yoke with the topyoke still attched,sorry don't know if feaseable sure someone here can advise...LP.Anyway best of luck ,BobH. 

[fido]

Another idea would be to heat up the yoke then use a watering can or similar to fill the fork with cold water. The rapid contraction of the steel could release it.

[Topdad]

Fido, nice idea ,love people who channel there knowledge to practicable applications ,makes sense and full marks ,kicking myself for not having thought about it , by the way in an old post did you say you are a metalurgist ? if so have you ever worked with my Brother Stan Hebdon from Crewe, He's pretty well known in the industry Best wishes BobH

[duTch]

 With regard to Jules' idea,(ball joint separator),I found this link couple yrs ago, when I was searching for whitworth spanners and figured it'd be useful at least for entertainment
http://www.triumphspitfire.com/Toptool.html

  have used # 5 which is what caught my eye, but in this case I think #9 may be 'similar' to Jules' idea??
 If not all those ideas are good, but to 'expand' on Jules' idea#2, how about tightening the bottom yoke pinch bolts(otherwise it will just 'slide'), and from the hardware store, threaded rod short enough to fit between top and bottom yokes+ 3 connector nuts (you know the long ones for joining two lengths together??)+use two couplers or similar for locknuts to screw against each other at one end of the rod and against a yoke of your choice, and the other single one other end screw out against locknuts and other yoke, putting yokes under expansion pressure(remember-tightening the bottom yoke pinch bolts), then use all other pre-mentioned options till it cracks-'cept the grinder!!

   Heat but not too much,+

[bsa-bill]

Hi Jesse
Can't recall any mention of fork trousers, if by chance there is none fitted  then could you refit the top nut and use a puller to grip on the bottom of the top joke and place a nut or something similar on the top nut and apply pressure, not a lot to grip on the bottom edge but might work with a suitable puller.
now your going to tell me it has trousers fitted

[RichardL]

First,  I would be concerned about giving a top nut too solid of a whack while the stanchion is stuck.  As far as I can tell,  based on the results of a long ago accident,  they are ductile iron and could bend or distort.  Considering the lack of success so far, I am rather certain that success will only come with trousers or gaitors off (isn't that always the way). Now,  you might try a very large pipe wrench on the stanchion whilst applying the heat, assuming you don't mind hidden scars under the trousers (isn't that always the way). Back to pounding, consider slitting lengthwise a piece of pipe that is the exact length between bottom of top and top of bottom trees. Wrap around stanchion and hold together with hose clamps. Now, when you beat on the nut (with bottom tree clamps loose, both trees will take the force and bending will be half as likely. Also, this means the energy of the whack will not be lost in top tree flexing.  I'll stop before descibing my idea for a puller based on the split pipe.

Richard L.

[RichardL]

Commenting on my own comment,  pounding on the fork nut may also be bad for the bearings.

Richard L.