Cutch Tube repairs, See lots of these done, but WHY needed Options

[barefoot]

There's a plethora of repairs done to fix broken away clutch tubes, but there should never be any thrust load on this tube. It's just a conduit to route the cable thru the tunnel area.
Only thing i can think of is if the cable sheath in the engine bay is a little too long, then the fixing at the tranny bracket that also holds the pully to rotate the cable 180 Degrees is not adequately fixing the aft end of the sheath, then the thrust load pushes on the end of the clutch tube where it exits the firewall.
I'm getting the the point of re-installing the engine and then can check if the sheath is loading against the tube and not the aft end fixing.
Anyone been thru this already to help with this mystery ??
Inquiring minds want to know (IMG:style_emoticons/default/dry.gif)

[Tom_T]

There's a plethora of repairs done to fix broken away clutch tubes, but there should never be any thrust load on this tube. It's just a conduit to route the cable thru the tunnel area.
Only thing i can think of is if the cable sheath in the engine bay is a little too long, then the fixing at the tranny bracket that also holds the pully to rotate the cable 180 Degrees is not adequately fixing the aft end of the sheath, then the thrust load pushes on the end of the clutch tube where it exits the firewall.
I'm getting the the point of re-installing the engine and then can check if the sheath is loading against the tube and not the aft end fixing.
Anyone been thru this already to help with this mystery ??
Inquiring minds want to know (IMG:style_emoticons/default/dry.gif)

Unfortunately, the realities of physics, binding at choke points & gaskets, etc. conspire to put some movement & thrust on the tubes, such that Porsche used to have a fix kit for the rear firewall punching through (IIRC Jeff Bowlsby's 914 website has the TSB on it there), although they never did anything for the forward tack welded bracket in the mid-tunnel, other than recco opening up the tunnel & welding, or using a screw band clamp through slots cut in the D-side of the tunnel wall/floor.

In addition to Mark's recco for a D-washer, &/or I'd suggest a welded plate on the outside of the firewall to reinforce that area, which is easier to do the fix without removing the interior.

Original Porsche TSB Firewall Fix Kit installed late 1970's by my guy at Hans Imports -


Screw Band Clamp fix done at the same time per their Service Bulletin -

.

I include the above for historical purposes on the old factory fix, since there are other ways to as noted by myself & mark, etc. to do this today. When mine goes in for resto/rusto/accident repair bodywork, I'll have these removed & properly welded/reinforced "while I'm in there". (IMG:style_emoticons/default/smile.gif)

Cheers! (IMG:style_emoticons/default/beerchug.gif)
Tom
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