4th gear knock

[jfinn]

I bought an 85 fj100 that was of the road approx. 7 years. After getting  it road worthy again, I started it and ran it down the street. I noticed a knocking in 4th and 5th gear. I put it on the center stand and ran thru the gears, same results  - knock in 4th and 5th. I decided to go forward, register the bike, inspect it and give it a try. After a just a few miles the knock in 5th went away. However, after about 800 miles 4th is still knocking. It shifts fine up or down, I can power thru 4th with no problem, other than the knock getting softer or louder, but 4th is strong thru the revs. I put Klots 10/40 in this year hoping that might loosen up things - it has made a difference in some of the other noises but not 4th. I have only recently put about 200 miles on it this year (knee surgery couldn't shift).

Any Ideas? My Yamaha dealer said 4th is blown. Why would the same knock in 5th just go away?

Good thing the FJ has lots of guts - I just skip 4th and go 3rd to 5th.

Looking forward to your thoughts.


Thanks
John

[Mark Olson]

John ,

sounds like something is stuck in the gears, put some motor flush in it and ride in 4th changing speed up and down then drain the oil and fill with fresh.
if that doesn't clear it up you gotta tear it down and see whats messed up.

after sitting for all that time the clutch plates can dry  out and end up in your trans gears.

good luck , wish I had better news.

[jfinn]

I seem to notice a couple of other things. My clutch may be wearing out - It is catching close to the top of its range - so I can shift without pulling it all the way in (1/4 in). It still feels strong and doesn't slip at all. I've rebuilt the master and slave cyl., new fluid and bled the system. It feels smooth throughout the range. I can hear a slight knock when I shift into 4th with the clutch pulled all the way in, then it gets stronger as I let out the clutch and the gear engages. The frequency of the knock will increase with RPM but not at the same rate. The lower the RPM - the louder the knock, as the RPM's increase the knock gets more frequent but softer. If I apply the power it will soften up but never goes away.

John