I just installed a jdm fd, and am replacing the 3-4 synchro while im at it cause both gears grind on upshift. I ordered a new sleeve set, but when i look at the current one, it looks perfectly fine, and it appears that the "triangle teeth" on both the 3rd and 4th gears is what is worn, not the synchro rings. How did this happen? I thought the synchros were designed to take most of the wear so that the gears did not.... They are made out of two different materials, the gear ring teeth look like hardened steel and the synchro rings look like brass.
So should I order a new 3rd and 4th gear as well?

 

post some pictures!

 

How does the inside surface of the sychro feel? See those splines..looks like threads....are they sharp. They should be..this is what causes the necessary friction to slow things down and mesh.

As far as the teeth on the synchros go, they are not usually symmetrical (toyotas anyway). They are shaped a certain way to help mesh. Hope ypu know what i'm trying to say. In other words, one side of the tooth might have an angle to it and the other straight/flat...looking left to right..not front to back.

 

I'm woring on the pics... gotta find a new place to host. I'll go look at the splines right now.......

 

I've no clue

 

synchros usually go before a gear will. Just replace the synhcro and associated parts that are defective.

 

Looks to me like the syncro is FUCT! Looks just like mine did...
See how the teeth on one syncro are all nice and thick? The other should look like that also yet theyre all worn down (at least this is what I was told when mine looked the same)

 

Reason #1 why I hate double synchros!!!!

BTW nice LCR avatar!

 

Can anyone elaborate on what I'm looking at? What are the various components shown in this picture?