Hey all my name is jason i have a 2005 f4i with 65,000 k or 40,000 mile on the clock, iam now due for a gearbox rebuild second an thrid have gone, the dog gears have worn and wont lock in also one of the shift forks is badly worn, i was just wondering what miles you guys have got out of your gearbox. My bike is my daily ride plus twisties on the weekend, i have a -1 +2 sprocket set up on it and it is service every 5000 k or 3000 mile.

 

Mine started jumping out of 3rd gear at 114,000 miles. Replaced 2nd, 3rd, and 6th gears and the shift fork, and all is well, never had a problem since (at 180k now)

 

What sort of rideing do you do, i tend to use second and third gear a lot but i didnt think you would ever wear out sixth gear

 

56K km and a rare false neutral is about it. The Honda gearbox is famous for reliability and should last miles and miles. Do you clutchless shift or has the bike had hard wheelie landings?

 

I always use my clutch but yes sum time do wheelies but dont land it to hard

 

I do alot of commuting, long trips, mountain riding, etc. But prior to having the trans problem I did do my fair share of clutchless shifting, which I later found out is what kills them over time. Since then I rarely ever clutchless shift, and it's been perfect ever since. A Factory Pro shift star kit also helps alot with the missed shifts and false neutrals, which are also very bad for the shift forks and gear dogs

If you fix yours yourself, you'll see why I replaced 6th gear (and you'll need to as well). The transmission has 3 gears called "slider gears". It's a gear that has gear dogs on both sides, and has a slot in it that the shift fork rides in. The gear itself slides back and forth on the input/output shaft wherever the shift fork directs it, and slides and locks into the gear next to it on either side to lock that gear to the input/output shaft and engage the gear. 6th gear is the slider gear for both 2nd and 3rd gears, so every time you shift to 2nd or 3rd gear, you're actually using 6th gear to engage them by moving it one way or the other. They go in order on the shaft of 2nd, 6th, 3rd, etc. Really much easier to understand once it's out and you can look at it.... they're really incredibly simple and easy, way more than you may think

 

Im around 38,000 now and I get the occasional false nuetral when Im really on it hard and don't shift hard enough, but its done that since I bought it brand new.

 

Thank you for your replys and i just finshed pulling it apart sixth is worn to .

 

You're a beast thirdgen

 

Hey all i thort i just let you no i found out what caused me to kill 2 3 an 6 it was a bent shift fork .