throw-out bearing forks broke...why?
 

anyone have any idea what would cause a fork to break?
yesterday i was driving when i came to a light, light changed, i started to go, the the car infront of me stoped again. i press the clutch peddal and it went straight to the floor. imediatly i think...'damn my slave cylinder just went'. i pull the peddal off the floor with my toes, and press it again just for shits and giggles to assure myself i have a hydrolic problem.
as i depressed the peddal the second time, i hear major grinding and then motor just cuts out.
tow the car away. put it on a lift, and open the door at the bottom to take a look inside. there is hydrolic fluid everywhere as i am taking the cover off.
as i am looking around inside, the presure plate is eaten up pretty good and a piece of the fork fell out as i tried to move the flywheel. also i pulled the slave cylinder out to see if the pin was still there being spring loaded and now the fork is not there. that pin is also in there somewhere. no longer insight. :confused:
i know how to replace all this, that is not the problem. i am wondering WHAT THE HELL WOULD CAUSE THAT FORK TO BREAK?
has this happened to any of you?
a few answers for some questions you may have.
-i have a rps clutch/PP in there now.
-i was not beating the shit out of it just prior to damage(although i do beat the shit out of it.
-clutch has about 14k miles on it.
-clutch plate is still intacted

TIA

I've never had one break in a 7, however I have heard of the breaking due just plain fatigue, or because of an aftermarket pressure plate with high spring rates. I've had them fracture on cars I drag raced, again, due to the high spring rates in the pressure plate.

that is what i was thinking was because of the presure plate, but damn i didnt think the spring rate on that plate was that high.
thanks for the input though. i will have to look into that.
what are you guys all running for a clutch/pp?

One thing to keep in mind is that if there is a question of durability of the fork, you can add strength by welding to "weak" area. That's what I had to do. Where the fork arm split to "Y" is the point mine would fracture. My son's Trans Am did the same thing, and he also blew out the slave cylinder.
I'm only running stock TII clutch assembly....No problems.
Good Luck
Don

That is a little odd that the fork broke. That's one of the few tranny parts I've heard of that people have no or few problems with.

I use an OS Giken twin, just like a lot of the Japanese forum guys do, and I haven't heard of anyone breaking any forks. Weird:confused:

When I replaced my original clutch.
I believe (think) I broke the "fork"
in my transmission also.. Of course
i paid a arm/leg for a stock clutch, PP,
Throwout bearing and the fork thing.

I thought I might of broken the FORK thing
by Jumpstarting my car, when it used to stall
with the AC on. Jumpstarting as in Starting
the car by poping the clutch as the car is rolling.

BTW: I NO LONGER Roll start my car PERIOD.
Always turn key. due to the above..

the forks break occasionally, usually its with an aftermarket pressure plate but not always. i've seen about 6-8 broken ones, out of the probably 50 times we've had a transmission out

mike

Yeah, my fork broke too...about 2 months after getting my ACT clutch and pressure plate installed.

My mechanic was not surprised. He said that it is a pretty common failure on the FD.

Mine broke the same day I had the Spec stage 3 clutch installed.

Well I have my tranny apart right now getting a new RB Flywheel and Spec stage 3 Clutch and Pressure Plate. Is there anything I can do to the fork while I have it out of the car to prevent this from happening to my fork? Thanks.

Did he recomend an "aftermarket" replacement? or did he just use an OEM one again?
if anyone has a link to help guide me to a replacement other than oem that is stronger, please do so. i have not heard of any.
otherwise i am going to have to dish out $73 for a new fork assembly that is obviously not strong enough for an upgraded PP.

thanks all for the input :)

I've broken two of them in the same week. The first went out simply of fatigue.. it had maybe 150K on it.. the replacement broke because i recieved the wrong pressure plate. Snap! Talk about making you feel sick. Anyways.. got the correct pressure plate in and all is well.

I will bump this because I need to put my Tranny back in but I want to see if there is any precautions I can do to make my stock fork stronger. Can I weld some pieces of 3/8" steel to it to strengthen it. I don't want to have to take my tranny back down to replace it if it breaks. I am installing the Spec 3 clutch and pressure plate with an RB flywheel this week. Any help would be great. Scott

i dont know of any aftermarket forks, maybe a twin plate clutch would be better than a big single?

mike

Scott,
sounds like we should just replace the stock forks. i guess now everytime i drop the trany i am going to replce it. just like a throwout bearing...

thanks

Take it to a welding shop. Show them where you need extra support. These forks are not very meaty,so see if they can possibly electric weld support/bracing. Most welders are pretty innovative...See what they say.

He just put in another OEM fork. That one has been in the car for more than a year now, and I've had no problems so far with the new one. I actually had the transmission out a couple of weeks ago, so I took a look at my fork for cracks etc, but didn't see any, so this one seems to be holding up well. As for aftermarket replacements, I don't know of any.

:)

Well I have a extra fork an my extra transmission if you are interested :)