bsaweezer Posted January 4, 2010 Report Share Posted January 4, 2010 Can any one help i am trying to renew the fork seals on my ty 250 twinshock and cant manage to see how to seperate the fork stanchion and slide. i have tried the allan headed bolt at the base of the leg but its just turning and i cant see how to hold the damper tube to stop it turning. I ve tried inserting the spring and rebuilding the leg, then also compressed the leg to increase pressure against damper tube but its still turning any ideas? Bsaweezer. Quote Link to comment Share on other sites More sharing options...
andy m Posted January 4, 2010 Report Share Posted January 4, 2010 Best bet if they haven't been apart in a long time is to go to a garage where you can use an air gun to strip them. Make sure the allen key socket is a good fit they should come apart easily with air. When you build them back up use coppaslip on the bolt they should come apart easily next time. There were long special tools for holding the inner part in the Yam workshop tools years ago like a square spike end if that makes sense. Quote Link to comment Share on other sites More sharing options...
woody Posted January 4, 2010 Report Share Posted January 4, 2010 If you have access to an air socket driver and compressor the sudden shock of the air socket applied to the allen bolt is usually enough to crack it free (with the fork compressed as you have already been doing) If you don't, the way I used to do mine was to cut a piece of wooden broom handle to a length where it would just fit into the stanchion (fully extended to about a few millimetres short of the top. Then, fitting and tightening the fork cap would push the broom handle down onto the top of the damper rod and (hopefully) stop it turning. I then used a T-bar allen key and clamped a pair of mole grips to it and then hit the mole grips hard with a mallet to try and shock the bolt free. May sound bizarre but worked for me as I couldn't see any other way of stopping the rod turning (in the absence of whatever the special tool is) On Ossa and Bultaco forks, the damper rod has a slot in the top so you can just put a long handled screwdriver (or similar instrument) down the stanchion and into the slot. The Yam damper rods don't have this so I've no idea what the tool is like that locks it. I've seen other recommendations that suggest screwing a longer bolt into the fork leg drain holes that will screw into and lock the damper rods and prevent them from turning, but I've never been confident that this wouldn't damage the rods or possibly strip the thread in the fork leg. Quote Link to comment Share on other sites More sharing options...
bengtphorqs Posted January 5, 2010 Report Share Posted January 5, 2010 What year model TY250 do you have? I just took a quick look at the Owners Service Manual for my 1974 TY250A. All it says in an otherwise fairly complete manual is "Disassembly procedure for individual fork tube assemblies is found in DT250A / 360A Service Manual." The Haynes and Chilton manuals for the DT's are fairly easy to come by, unlike for the TY 250's. Hope this is of some assistance. Quote Link to comment Share on other sites More sharing options...
tony27 Posted January 5, 2010 Report Share Posted January 5, 2010 The damper rods have 2 flats on the top of them The rattle gun has always worked for me with the broomstick inside if need be Hopefully Feetupfun will be along soon to give you some better insights Quote Link to comment Share on other sites More sharing options...
feetupfun Posted January 5, 2010 Report Share Posted January 5, 2010 Hey tony27 you know me well I love Woody's broomstick tool idea but the rattle gun is just so fast. My record for TY250 fork seal change from go to whoa is 20 minutes with a rattle gun. I did make a tool to fit the round-with-two-flats type rod end, but soon after gave in and bought an air compressor. I'm sure the later TY250s have flats but I have a feeling that my 250A model didn't have any flats on the end of the rod. It also has the drain holes in a different place to the later TY250 twinshocks. Quote Link to comment Share on other sites More sharing options...
bsaweezer Posted January 5, 2010 Author Report Share Posted January 5, 2010 Cheers for the help guys! took the broom shaft root, top idea!! came to bits without to much trouble. restoration takes a step further in the right direction. Only the ty 175 and ossa 250 Mars to finish now. Trials bikes ehh, so much fun even in the garage Best regards Bsaweezer Quote Link to comment Share on other sites More sharing options...
richty250e Posted January 6, 2010 Report Share Posted January 6, 2010 Hi bsaweezer, I had the same problem on my TY250E. You can make life easier next time (and for tightening up) by filing the end of the damper tube with the two flats into a 12mm hex. Then use a 12mm impact socket (six sided socket) and long extension to hold the tube while you torque up or loosen of the bolt. see photo attached. cheers Rich Quote Link to comment Share on other sites More sharing options...
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