WR450 2012 Forks ...?

[joelchester]

Howdo....have succumed to a mates plea's to sort his forks out....he hit a square edge step at some speed and his forks have collapsed ! So,are they similar to work on as Honda (Showa) forks ? I have had mine appart on my CRF250x....and....what weight of oil do you reckon is best/how much (He aint got a workshop manual)...also...anybody any ideas what it could be ? It's like they have no spring in them...(They don't return!)....All seems very weird for a new bike....think my money is on,theres hardly any oil them...but am open to suggestions..(No fork bleeders on them either..so thats never been released)....Gentlemen,place your bets ?...as they say....Cheers,Joel.

[FORMA MOTO]

He has blown the cartridge inner seals, blown the oil out of the cartridges, and now they are held down by vacuum.

[joelchester]

Bingo..!..so is this a simple fork seal job ?or is it a 'special tools' take it to the shop job ? Thanks for replying .....ps Can you even get the cartridge seals...or is it new cartridges all round....? Just trying to help a mate,but don't want to stitch myself up too much....

Edited February 5, 2014 by joelchester

[FORMA MOTO]

Not the fork seals, the CARTRIDGE seals. 

Any work on that fork will require some precision specialized tools.

 

It's not hard, or complicated, but it is easy to do wrong.

 

SERVICE MANUAL

[joelchester]

Yup,I see I would need a cartridge holding tool at least ! (Checked the online service manual)...Got away with all special tools on my Hondas Showas...looks like it may be cheaper to take them to the shop...Cheers again.

[grayracer513]

The cartridge seals are not capable of holding a vacuum in the cartridge that would defeat the springs, for one thing. Oil would simply push down the seal lips and be pulled back in. It's not outside the realm of possibility that one or both inner tubes are bent, or that the springs bound when he bottomed it and either broke the spring seats or pushed the spring seat stop rings up the cartridge tube a ways.

 

You can get by with no special tools at all on the KYB TC fork, although the right stuff does make things simpler.  OTOH, if you do have to replace the cartridge rod seal, you will need to buy a tool for removing the cartridge head.

 

The right tool for the cartridge is a 49mm octagonal ring wrench, but any solid crescent wrench can be used *carefully* in most cases.  To extract the base valve from the cartridge, you can use one of the rear axle blocks inserted into the socket of the valve, rather than the 32mm octagonal driver.  A small crescent wrench will serve as the rod holder while disconnecting the rod from the rebound adjuster.

 

Download a manual HERE: http://www.yamahaownershandbook.com.au/?r=0

 

If you can't find one for the '12 WR yet, use one for any YZ450 from '06 onward; same fork.

 

A Word of Caution:  The manual is extremely confusing about replacing the cartridge rod.  Read this to clarify:

 

https://www.thumpertalk.com/topic/680824-base-bolt-jam-nut-clearance-06-yz-450-fork/#entry6860151

 

Let us hear what made them stick downward.

 

Use a suspension oil labeled as any weight from 2.5 to 5.  Nothing heavier.

[FORMA MOTO]

The cartridge seals are not capable of holding a vacuum in the cartridge that would defeat the springs, for one thing. 

 

GOOD POINT

[joelchester]

Cheers Fellas..am taking them to 'the shop' tomorrow,think it's a bit beyond me....although,I do like the idea of using the axle block as a tool...ha,ha...did they know ? Anyways the shop said they would do a full rebuild ...all seals,new oil etc for £105,so it seems like a better chance of an outcome,than one of my 'suck it and see' rebuilds...will report back when I find out WHAT WENT WRONG....again ,this is not my bike,I do my own Showas,but having seen the manual for these (Not entirely clear) a 'bow out' is necessary....dont think bad of me...ha,ha....

[cubera]

Cheers Fellas..am taking them to 'the shop' tomorrow,think it's a bit beyond me....although,I do like the idea of using the axle block as a tool...ha,ha...did they know ? Anyways the shop said they would do a full rebuild ...all seals,new oil etc for £105,so it seems like a better chance of an outcome,than one of my 'suck it and see' rebuilds...will report back when I find out WHAT WENT WRONG....again ,this is not my bike,I do my own Showas,but having seen the manual for these (Not entirely clear) a 'bow out' is necessary....dont think bad of me...ha,ha....

You're doing what I would do in this situation. ?