450 trans gotta be simple


3 replies to this topic
  • DIRTTRACKER0

Posted April 21, 2008 - 09:02 PM

#1

2003 yz450f i split cases replaced crank, shift forks 3rd and 4th gear. put cases back together checked shifting operation. i can shift it smoothly with the cam hub manually but when i install the shifter pawls and compression springs, install the shift lever it will shift to 1st then feels like nothing is there in 2nd, removed and inspected the compression spring, found i overlooked one spring was damaged and bent:bonk: . the local dealer only had one spring so replaced it. when i install everything it will only shift into 2nd, it will shift one time only into 1st gear then the shifter pawls seem to get out of alignment with the cam hub they lock into. i know there is something simple and stupid i am overlooking:confused: . i plan on installing 2 new compression springs could this be the problem or something else. inspected the pin that goes into the cam hub it is in place and locks in ok. this is driving me crazy:worthy: !!

  • grayracer513

Posted April 22, 2008 - 05:50 AM

#2

Once you shift to first, does the shift lever re-center itself?

When using the shift lever, does the cam rotate completely into first gear?

When you then try to shift to second, does the pawl engage the cam and rotate it, or does it pass over the notch?

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  • DIRTTRACKER0

Posted April 22, 2008 - 08:32 PM

#3

when shifting into first it seems to re center, but not sure if it is enough?

when shifting into second the pawl catch but do not turn the cam far enough to engage 2nd gear.

after thinking more about it and your re center question i will pull it apart again. i am thinking either the pin on the cam fork or the notch on the star hub where the pin locks into has become worn. what do you think.

i replaced the shift forks and 3rd/4th gear for popping out of 4th, but when i pulled it apart inspected and gauged parts i really did not see anything that would have caused it to pop out or jump in 4th. maybe the pin or notch was not allowing it to hold in 4th??

  • grayracer513

Posted April 22, 2008 - 09:27 PM

#4

when shifting into second the pawl catch but do not turn the cam far enough to engage 2nd gear.

Are you rotating the trans shafts to align the locking lugs on the sides of the gears? It's necessary most of the time.

i replaced the shift forks and 3rd/4th gear for popping out of 4th, but when i pulled it apart inspected and gauged parts i really did not see anything that would have caused it to pop out or jump in 4th. maybe the pin or notch was not allowing it to hold in 4th??

Jumping out of gear under a load is not the result of a fault in the cam or forks. It's the fault of worn locking lugs on the sides of the gears. This condition will bend the shift fork, however.





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