Clutch Suddenly Gave Up

[Uwon]

The car has been driven around the block several times since finishing the build. Grearbox shifted nicely up to third and clutch operated as it should. Well, Tried to back out of the garage and clutch suddenly gave up. Could not get it into any gear-just ground the gears as if the clutch was not depressed at all.
Background: Clutch is almost new. Clutch cable is new. Everything else, I.e. clutch fork, trani etc. came out of the donor car. I just inspected and cleaned everything up before reassembly. Trani was not opened up-just replaced the oil with Swebco.
So I re-traced all my initial assembly steps:
1. inspected pedal assembly and front linkage in tunnel.
2. checked clutch cable seating at rear by tunnel. Cable sheath makes a nice metal sound against the clutch tube in the tunnel.
3. re-checked cable basic adjustment with cable disconnected at 1.2mm.
4. Re-set cable pre-load with cable connected at 1.0mm.
5. Re-set clutch release distance to 25.0mm (stop on floor board).
With the rear wheels off the ground, it will go into any gear if, and only if, the rear wheels are freewheeling. If I apply the brake pedal while I try to put it into gear with the clutch depressed, then it just grinds away.
I'm getting the feeling that the clutch fork has bent or dislocated itself from the pilot bearing.
Any ideas?
BTW, I have also posted this issue in my build thead but would appreciate posting any replies/comments and suggestions here.
Evolution of a Carrera RST
Thanks in advance.
Johan

[Flat6pac]

I'm going to go with the fork on the TOB broke on the bottom finger.
Bruce

[DRACO A5OG]

^^^+1 "donor fork"

[rwest]

Double check the roll pin that holds the clutch pedal to the shaft of the pedal cluster- if that sheared, the pedal will move without pulling the cable.

[Jonny H]

Happened to me last week, started to judder, adjustment went out. One prong of the fork was split.

[Tom Sch]

[Uwon]

Originally Posted by rwest

Double check the roll pin that holds the clutch pedal to the shaft of the pedal cluster- if that sheared, the pedal will move without pulling the cable.

I got good pedal pressure and I can see that the cable and front linkage inside the front of tunnel moves the required 25mm. Just re-checked.
Thanks
Johan

[DRACO A5OG]

Ah man, sorry to read that. It would have been a easier fix :-(

[Uwon]

Originally Posted by Tom Sch

Jonny and Tom,
When one prong of the fork broke on your cars, did the other fork pop out of the pilot bearing groove? Any noise or rattle?
Johan

[DRACO A5OG]

OP, if I may, when the car is cold, have a helper press the clutch and then you reach into the gear box on top at the inspection port with your fingers locate the fork which will be on top of the TOB.

You can feel if the fork is moving or not, you may also feel the fork if it is fractured on top.

[Tom Sch]

Originally Posted by Uwon

Jonny and Tom,
When one prong of the fork broke on your cars, did the other fork pop out of the pilot bearing groove? Any noise or rattle?
Johan

no, the other fork did not pop out, no noise or anything else.
just no function of the clutch, no gear go in...

[Jonny H]

Mine split the other end from Tom's (near the splined hole). I could still just about drive the car after the cable was readjusted. Judder was awful. The prong didn't come out of the groove. The top prong went btw.

Managed to get home from 100 miles away!

[Uwon]

Ok guys, thanks for sharing my pain!
Not admitting defeat, I unhooked the cable from the release arm and got nice solid and smooth pressure when I moved the arm with the aid of a long screw driver. So, I then examined the arms and noted that the small one had a 1mm indentation where the adjustment screw rests. So I filed it off so I would get a better gap reading. I then reassembled and adjusted the gaps, tested the shifter before starting, started the motor and tried to shift-sounded like a first timer changing gears in a Model A crash box.
I would assume that since I still have clutch plate pressure at the release arm, the fork must be hanging on to the pilot bearing by one prong.
Tomorrow I'll drop the motor and trani and we'll no doubt have a surprise.
Cheers,
Johan

[Uwon]

Originally Posted by DRACO A5OG

OP, if I may, when the car is cold, have a helper press the clutch and then you reach into the gear box on top at the inspection port with your fingers locate the fork which will be on top of the TOB.

You can feel if the fork is moving or not, you may also feel the fork if it is fractured on top.

Draco, good point but I don't trust my petite wife to stand on the clutch pedal without slipping, so I may just use my el cheepo HF remote camera and save my fingers. LOL
Just trying to remember where the inspection port is on the 915 bell housing.
Johan

[DRACO A5OG]

LOL, have use two feet like my wife does


2nd Yellow Arrow

[Dr DIY]

This was my guilty party and why I say you should "never" do clutch removal without replacing this part - obvious exceptions are people who have their engines out regular and know the condition of their part. These are a known failure part. I had my clutch apart and failed to replace this then got to redo the entire job just a couple of months later. Call it an education.

[Uwon]

DRACO, camera provided limited view. Could only see the end of the top fork arm which looked ok.
I would not have been able to see a crack such as Mr. DIY's example above.
Engine almost out but happy hour called. D-day today.
Anybody know if there is a basic procedure to test trani on the bench without having to take it apart?
Cheers,
Johan

[Uwon]

Cracked clutch pressure plate.!!!
Johan

[theiceman]

cracked pressure plate .. why were you in there in the first place ? was it an engine rebuild ?

[DRACO A5OG]

WTF? How does that happen?