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RE: Clutch Pedal Noise Update
Thanks for your suggestions. On closer inspection I think the noise may be
a symptom of a much deeper problem....
TQC's have quite stiff clutch pedals, I'm beginning to wonder if mine is
just too stiff. The firewall supporting the clutch MC has a T shaped crack.
When you depress the clutch the whole MC moves about 2-3mm as the part of
the firewall supporting the MC flexes. Hmmm, this is not good. The crack
extends from near the clutch MC to two large holes for wiring harnesses. I
now envisage driving home from work putting my foot on the clutch and the
circular section of the firewall supporting the MC popping out into the
Aha! This is not such a rare failure mode as I thought..... (we are not alone)
On my brief check it looks like it will be awkward to get near the firewall
crack to weld it, TQC's don't have a lot of free space under the hood! I
believe I have two problems:-
1) Why did the crack develop, something between the clutch MC and slave is
not working properly, which parts of the system control the clutch pedal
resistance and how can I check them?
I believe that these cracks develop where they do because the metal is thinner in these spots due to the way the firewall panel is stamped at the factory - seems they hit 'em a bit hard and the material is
therefore thinner that it ought to be. This conspires with the considerable force from the master cylinder
and results in flexing and evental fatigue and cracking. The lower wire harness hole provided the starting
point for my crack that went up and over the MC. I also found another small crack, again right along
the edge of a bend in the stamping, between the clutch MC and the brake MC, was bout 1 1/2" long.
Checked very carefully all over and found no other cracks......so far..... The clutch MC crack had been
there for at least 1-2 years but there was not much I could do till I got the engine out of the way.
2) How am I going to fix the crack in the firewall?
I had mine TIG (Argon) welded by a Navy-trained nuclear welder. He did a *fantastic* job -
a true work of art and TOB - he asked for $30 - I gave him $40 - I know, BIG spender.
This was relatively easy as the engine was out at the time. :) (and still is) :(
He recommended against reinforcing with a plate, etc, said that would actually accelerate future fatigue.