Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (https://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   Damping rod holder (https://www.horizonsunlimited.com/hubb/yamaha-tech/damping-rod-holder-30854)

michal4 20 Nov 2007 21:02

Damping rod holder
 
Hi
Does anyone know what special tool is needed to disassemble front fork of 1991 XT 600 (3TB). The problem is a damper rod turning while trying to loosen the bottom bolt. I heard there is Yamaha special tool (but do not know the number). I’d like to make it myself but have no idea what it looks like. Does anyone have a picture of the tool?
************************************************** *********
Maybe someone had similar problem with a gearbox: It’s very, very difficult to shift to neutral when the bike is not moving and the engine is running. It’s getting impossible when the engine is hot. I have to shift to neutral at 20-30 kph. Then again, when the engine is stopped (even if very hot) – no problem at all with changing to neutral. What‘s the reason for this?

Thanks,
Michal

Martynbiker 20 Nov 2007 21:16

odd shifting
 
dont know if this is related but...... my 1989 XT600 was difficult to pull clutch in when engine was hot, it was good when cold, and cable was new one I had just purchased.
turned out that the routing was wrong and the cable was touching the cylinder and getting hot and then stiffening up when it expanded making gearchanges difficult.


Martyn

Flyingdoctor 20 Nov 2007 23:48

The easiest way to get the bolt out of the bottom of the fork without holding the damper rod is to use an air ratchet. Like the ones the tyre guy's use to get wheel nuts off. The hammering will soon have it undone. I've tightened it up the same way but getting the right torque is a bit hit and miss. If it's not tight enough oil will leak out !

Nigel Marx 21 Nov 2007 00:25

Clutching at broom handles!
 
Sounds a lot like the clutch is dragging. As suggested, check the cable routing, check to see that the cable outer has not been crushed so that it is gripping the inner, and check adjustment (should be a few mm free movement of inner cable at the lever). If these are OK, then it may be a warped (slightly bent) metal plate, or the fingers of the clutch basket have grooves in them, thus not allowing the plates to properly separate. Do you have any idea how many kms old the clutch is?

I don't know about the XT600 but on other Yamahas I have held the damper rod on the inside with the end of a wooden broom handle. It needs to be a thin broom handle, and you have to hammer it in a bit for it to bite into the socket in the head of the damper rod. It's an easy thing to try. Also Flyingdoctor is right, an air wrench usually does it, but I have had to use the broom handle AND air wrench on several occasions.

Regards

Nigel in NZ

cyberzar 21 Nov 2007 09:53

Quote:

Originally Posted by michal4 (Post 160117)
what special tool is needed to disassemble front fork of 1991 XT 600 (3TB)

it's a 27 mm nut (external size), so you need to buy about 60 long screw for that size of nut, weld a nut at one end and a T handle on the other

Bill Ryder 21 Nov 2007 16:17

XT600 forks
 
Just did the forks on a 90 XT600 (one of the few inported to the USA). As I have done on lot's of forks I stuck my 10 mm 3/8 drive allen in the fork bottom, I made a long one from a straight peice of 10mm allen stuck in a 10mm socket. Then I laid the fork leg on the floor and plugged my trusty 3/8 ratched in and whacked it with a hammer. This usally breaks the bolt loose to where I can twist it to start to loosen the bolt. Now the damper rod is turning so I plug my 3/8 air wrench on and put the spring back in the fork and while pushing down on the fork spring I zip the bolt out with the small air wrench. When putting the bolt back in I like to use some silicone seal on the bolt threads that is very vibration proof and prevents leaks.

Lone Rider 21 Nov 2007 19:03

Use a stick of wood down in there to apply pressure.

michal4 21 Nov 2007 21:21

Thanks All,
Regarding damping rod
I will test all the methods you describe: air wrench, broom handle. It is interesting how strong the allen bolt keeps the damping rod. I used a lift to compress all the length of the spring (even a bit more) but still was unable to stop the damper rod. Then tried to make a tool to stop it. Took 27 mm nut, put on an end of wooden stick and put that into the tube. It fitted perfectly but I couldn’t hold the damper – the stick with the nut rotated almost freely inside. It looked there is no interaction between bottom allen bolt and 27mm nut on the stick. Then I rejected the 27mm hypotheses.

Regarding gear box neutral
The bike is 16 years old, 4 years with me, I did 40K km. There was always a problem to shift to neutral with running engine. 3 years ago I opened the engine, did some research. The 5-th gear was worn – so replaced with new one. It had also B size piston. I guessed the bike was 80K km then. Clutch basket fingers had small groves 1-.5 mm (20-40 mils). I blended it. The gear box looked OK, no problem with changing the gears. After this improvement (and assembling of course) it was the same: when engine was stopped – no problem, when running – problem, when hot – not possible to shift to neutral at all. 3 years later it got even worse. Can it be the clutch?
Thanks again
Michal

Lone Rider 22 Nov 2007 00:20

You want to mash a stick (board, or something that will semi conform to the grooves) against the top of the rod (but is wider than the rod) as you turn the bolt.

If that won't work, take an air gun and a few cuss words to it...

GeoffE 24 Nov 2007 14:35

Quote:

Originally Posted by cyberzar (Post 160176)
it's a 27 mm nut (external size), so you need to buy about 60 long screw for that size of nut, weld a nut at one end and a T handle on the other

Hi,

The Yamaha part#s appear to be 90890-01326 (T-Handle) & 90890-01388 (Damper Rod Holder 27mm). There is a reference to it in the 3TB Service Manual and the very small drawing looks very much as described, although with it being purpose made there is no need to weld the two together.

Ciao,
Geoff

Footnote - hows your Italian (although the pictures say a thousand words)? 'LINK'

cyberzar 25 Nov 2007 14:48

special tool
 
ok here some pics taken from a tutorial made from a friend.. ciglio from xt600 italia

two nuts foer each end, threaded bar size 18 (27 nut), rubber along to avoid scratches on internal of stanchions.

cyberzar 25 Nov 2007 14:49

final pic
 
and here is the completed hyper tech tool! :thumbup1:

XTfubar 26 Nov 2007 06:09

Well..blow my seals !
 
Hi..the only thing I've done with forks is to change the seals. I overfilled the fork with oil, sealed it back up and then compressed the fork with a hydraulic jack to push put the fork seal( after removing the circlip).Otherwise I've heard an impact wrench is usually required.

Mick DB1 10 Jan 2008 18:08

With regard to a tool to undo yer forks
I got a 12mm setcrew 50mm long on to that I screwed 2 nuts ( 12mm )
onto the end of that I welded a 5/8 whit nut That nut slips over the remaining thread
Then I put a 19mm socket on the setscrew end ( with the help of the extra nuts it stops straight ) on that I put 2 -300mm ( 1 foot ) socket extensions
then ratched it undone
I had to do it this way as the capheads at the bottom of the forks were all gunged and rusted into their reccesses
After undoing the forks I roasted the fork ends with a blowlamp and easing oil did the rest. When I replaced the setscews I wraped them in PTFE tape to stop ingress of dirt and water

HTHY Mick


All times are GMT +1. The time now is 02:36.


vB.Sponsors