Rebound adjuster just keeps spinning around

[wiGGy]

The rebound adjuster on one of the forks on my 04 450EXC just keeps on spinning when I try to wind it in to full rebound. I can wind it out all the way and it stops ! I swapped the fork spring in it last night so I must have done something then, any ideas ?

[Soap Dodger]

Had a similar problem myself once and was well frustrated with the bugger. Try compressing forks using a tie down or ratchet (tie to handlebar and bottom of "other" fork leg so that the spring pressure inside will stop the inner cartridge form turning and this should then "grab" and stop it from spinning and hopefully it will then undo.
Hope it helps

[wiGGy]

I pulled the cap off the offending fork and it would seem I've lost a bit length in the rod/tube that moves up and down when I screw the rebound knob. It doesn't push the rebound needle down far enough to bottom it out. The rebound knob goes it's full travel and the 2 halves of the adjuster knob separate which leads to the spinning.

Is it possible I've lost a bit off the adjuster rod/tube which in effect will shorten it ?

[Terry Hay]

There should be an alloy tube in the centre of the damper rod. Make sure this is in place. The two piece assembly in the cap is easy to re-install. First wind the rebound adjuster fully in. Then simply screw the lower portion into the cap using your fingers. It has a phillips head recess which will locate onto the male counterpart inside the cap. When it feels like it had bottomed out continue to apply pressure with your fingers and rotate the adjuster on the cap outwards with your other hand. The two parts will marry up and live happily ever after. Before re-installing the cap onto the rod ensure that the black plastic spring guide is wound down the rod as far as possible. This will allow the cap to bottom out on the rod prior to resting on the guide. After the cap is in place bring the spring guide up to meet the cap and lock securely.

[wiGGy]

Terry,
I found that the plastic spring guide wasn't wound down all the way on the piston rod. This will account for not being able to bottom out the rebound adjuster. I reassmbled everything and now I've found that I have 34 clicks over the full travel of the adjuster. The other fork only has 28 clicks over it's full travel, is it OK to have such a difference between sides ?
As rebound is set from full hard, I'd imagine that 10 clicks out from full hard on both sides would be the same even if one side has 28 clicks and the other has 34 clicks over the whole range of rebound adjustment. :ww

While I'm here, what should I use to clean the fork internals with ??

[Terry Hay]

If you are disassembling the forks completely I would use some turps followed by some contact cleaner. If you dont wish to disassemble the forks but simply wish to get most of the old oil out- Drain the fork completely including pumping the cartridge to expel as much oil as possible. Then pour some fresh oil in the fork and pump it around. Now expel this and refill with fresh oil again. Set your levels and you're away.

[Bowy1970]

Hi Guys, sorry to drag up an old thread but I have just found that I have a spinning rebound adjuster of my newly aquired 2009 450 EXC - I have read through a few discussions and understand what the cause could be but, can this be fixed in the bike and what actualy happens when I unscrew the top cap?

[dwb79]

Hi Guys, sorry to drag up an old thread but I have just found that I have a spinning rebound adjuster of my newly aquired 2009 450 EXC - I have read through a few discussions and understand what the cause could be but, can this be fixed in the bike and what actualy happens when I unscrew the top cap?

The 10mins it takes to remove the front wheel and the fork, will make the job so much easier.

Below are a few pointers to help get the job done.

• Loosen the top tripleclamp bolts and then loosen the fork cap before removing the fork from the bike.
• Wind the rebound adjuster all the way out until it stops before dismantling the fork.
• With the fork removed, unscrew the top cap and allow the outer fork tube to slide down to the "bottomed out" position.
• Grab the fork spring and compress it enough to expose the alloy nut on top of the black plastic spring guide. You need a thin 22mm spanner for this spring guide nut.
• With the thin 22mm spanner in position, let the spring come back up against the spanner. This will hold the spanner in place and prevent the cartridge rod from dropping down inside the spring once the cap is removed.
• With the 22mm spanner and the 24mm spanner/socket on the fork cap, you can unscrew the fork cap.
• Now you need to wind the black plastic spring guide down further on the cartridge rod with the 22mm spanner. This was the original cause of the rebound adjuster not working properly. You may have to hold the threads on top of the rod with a rag so you don't cut your fingers.
• Once the spring guide has bottomed out and wont turn further, you can refit the cap and continue to reassemble the fork.
• Set the rebound clicker and preload adjusters.

If you are going this far, it might be worth pulling the other fork out and doing a simple oil change on both them at the same time. Especially if its new to you and you don't have a full service history, or if the bike has done more than 50hrs since the last service.