Damn those rb25/26/z32 transmissions...

[Booztd 3]

I swear, I'm *this* close to going auto. 3rd broken shift fork in a few monts....I'm getting tired of pulling the trans.

Heres what it looks like in the car

http://www.booztd3.com/Videos/...k.wmv

Happened around 3-4pm today, fixed and on the road now, we'll see how it holds up on the drag strip tomorrow, guess I'll try shifting a little easier/slower.

[Carl H]

isnt 3rd the known weakness in the z32/rb26/25 transmissions, would have thought there would be a fix for it...perhaps cryotreating would help?

[Booztd 3]

isnt 3rd the known weakness in the z32/rb26/25 transmissions, would have thought there would be a fix for it...perhaps cryotreating would help?

The syncros (or insert springs) for that matter are the known weaknesses. Guys will develop grinds going in to 4th gear typically.

This problem is due to shifting to fast. The shift fork is pretty weak as its made out of cast aluminum. When you're ramming 4th gear, the synchro cant get the next gear up to speed quick enough and the fork just snaps in half

I am working on sending one off to be CAD'd and then maybe running a batch of billet shift forks, however I'm not sure if another problem somewhere in the trans

[Cjmartz2k]

What is the typical fix action for this (besides billet stuff)? Do people just replace the fork or just rebuild the whole transmission? Is it easy to replace by itself? I was going to run some Redline heavyweight shockproof to try and stop it from grinding.

BTW, it usually doesn't grind at all when it's cold, and does it a lot when it's hot. It's strange though, it's as if there is no synchro at all there when it grinds. It almost falls into 4th (just grinds and bounces back off the gear) when I just pop it out of 3rd somtimes. But them sometimes, it'll be hot, and it feels normal (I can feel the notchy-ness of the synchros resisting and it won't grind).

[StricNyne]

nismo makes a fork i thought

[Shocker]

how ****ty, wow, was sounding so good, you were on the street too....... wonder if it gets injured at the track.. stress cracks and so forth, then it eventually just snaps... have any pictures of the fork removed while broke?

[gawdzilla]

damnn sucks. that brings up bad memories of when mine gave up going in to 3rd. what gear oil are you using? i use redline heavy shockproof, probably switching to light this winter.

how "hard" are you shifting? i assume you're not clutchless or power shifting. since i put in the new trans i really try to take it easy on the shifts just to give the synchros an extra split second to match speeds. takes a lot of self control but i'd rather give up that extra .1 than break a trans again... if you're big time into dragging it then i'd think about going auto, they're faster anyway

[Shocker]

damnn sucks. that brings up bad memories of when mine gave up going in to 3rd. what gear oil are you using? i use redline heavy shockproof, probably switching to light this winter.

how "hard" are you shifting? i assume you're not clutchless or power shifting. since i put in the new trans i really try to take it easy on the shifts just to give the synchros an extra split second to match speeds. takes a lot of self control but i'd rather give up that extra .1 than break a trans again... if you're big time into dragging it then i'd think about going auto, they're faster anyway

faster but not as fun, and just to easy......

I say hopefully find someone to CNC a new shifter fork out of stronger materials.... That way others can purchase them when the power is just too great.

[Darius]

I'm assuming the shift fork was designed to be the weak part in the transmission for a reason. If the fork was built to be stronger, what is the next weakest part that will fail? I'm no transmission expert, but I'm assuming this was thought through as being the easiest part to replace inside the transmission without having some catastrophic failure in it. I'd say replace it with the CNC'd part and beat the living $hit out of and see what goes next, if anything at your power level.