So after some shipping snafus, I got all my parts here (new forks, clutch, removal tool, seal etc)
For anyone who has installed a Muncie clutch 4, how free moving is it supposed to be, Last time I installed it, it was easily movable with one pinky finger, but had noticeable resistance. Is this correct?
I'm here to deliver my final report from this incident and hopefully marking this as closed.
Here's the lowdown:
Due to the recent unavailability of the Luk Clutches as well as my poor experience with getting the correct components into them I decided to go with a SACHS clutch. They seem to be well known throughout the VW world. I used one in my sand rail a few years ago to good result. I noticed a few differences between the SACHS clutch and my old Luk set.
A) The throw-out bearing face was larger than the LUK kit, and the bearing was significantly heavier. Height was the same. B) The pressure plate was heavier in weight than the LUK plate and had flatter release spring fingers, likely to match the larger face of the bearing.
I spoke on the phone with SACHS, they mentioned that there kit has the exact same release force as the OEM pressure plate, but a higher clamping force. (I don't know how they accomplish that but from driving tests I can definitely say the pedal is no stiffer than a reference Fiero with a original clutch). I also learned from the SACHS representative that the clutch disk itself is the same as the LUK model (SACHS is the parent company to LUK) but the SACHS kits uses a more upscale pressure plate and throw-out bearing.
I also installed new fork bushings and a new fork.
This brings me to the meat and potatoes of why I am making this post.
Fiero Store throw-out forks.
I believe I have found an issue with them. I have already contacted the Fiero Store and rest assured they took my observations seriously and are acting accordingly to determine if what I have found truly is a fault. First and foremost finger alignment. The fingers on both of the forks I have received from them (The broken one and the current replacement) Were slightly out of alignment, one being higher by 10/1000s of a inch to the other, relative to the shaft. This resulted in quite a fight getting the bearing on the collar of the transmission. The first time I did a clutch in my novice excitement, I didn't pay much notice to it and managed to fight the bearing on and had relatively "acceptable" movement on the collar (one finger and a significant amount of force to slide the bearing). This is why I believe my clutch pedal got "crunchy" feeling after installing and getting warm, and why I believe the bearing and fork failed. As heat expanded the out of alignment fingers it caused the bearing to 'twist' relative to the axis of the collar, causing binding and eventual failure of the fingers on the fork.
My solution to this misalignment was put the fork in a vice and carefully and evenly shave down the opposite sides of each finger until they were level with each other. A little bit at a time. After each pass I reinstalled the fork and attempted to seat the bearing each time it would fail to slide on to the collar easily I would pull the fork and repeat the process until it would seat and slide easily. This left me with a fork that had fingers about 6/1000ths thinner on each side. The bearing has just a tiny bit of up and down play on the fingers and installs and slides easily on the fork. The bearing now freely moves on the shaft and can actually fall down the collar with gravity when the transmission is sitting on its back.
I also notice the clock of both fingers relative to the key bolt slot for the clutch arm was a few degrees farther backward on my old fork than my new fork. (I have no reference to my original as it was so broken I decided just to cut it out to save time) This, I believe is why I had issues with clutch disengagement (if you remember my earlier posts) as my clutch arm was moving enough, but because of the clock of the fingers on the fork, relative to the arm, it was not able to fully disengage the clutch. I noticed this difference through a significant change in clutch actuation when my new clutch was installed. My clutch used to disengage way down at the floor and this was with Rodney's banjo turned way out. Now it engages right at the top, with the OEM banjo length. This is using the same arm, pedal and clutch and slave bleed. (I did not remove them during the swap so I am comparing only the arm and the banjo, I did not rebleed after installing the clutch)
Now I am left with a car that shifts like heaven and a absolutely buttery smooth clutch pedal that disengages exactly as it should.
My notes for those who don't want to read the whole post would be:
A) Pass on the LUK clutches for now until they get there quality under control B) DO NOT cut out your old fork, even if its broken so you can verify the clock of the fingers on your new fork. C) If the bearing fights you going on, somethings wrong (should be a no brainer but I was stupid enough to ignore it) D) Fiero Store arms may be out of wack, pending investigation, verify verify verify before installing.
Sorry for the huge post but I'd like to make this available to anyone else whos planning a clutch job when the weather thaws out, I chose a great time to do it outside during this nasty -10 degree cold front we are having. Gotta love Wisconsin.
