Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ Clutch Tube repair

Posted by: trekkor Nov 16 2006, 04:28 PM

I want to open up the center tunnel to inspect and repair the broken clutch cable tube. It has broken away and that has contributed to the clutch cable fork that attaches to the pedal bending and breaking during my last track day.

When the tube breaks, the cable pulls from an angle and creates uneven stress on the fork.
Also, a broken tube make it difficult to properly adjust the clutch.

I would like to see a picture showing an access hole above the tube location.

thanks


KT

Posted by: Rand Nov 16 2006, 04:38 PM

Try a search in the classics for "clutch tube." There might be a thread in there with some good pics.

I don't know if it has the pic you're looking for but check this:
http://www.914world.com/bbs2/index.php?showtopic=28313&hl=clutch+tube

Posted by: Mueller Nov 16 2006, 05:27 PM

cutting the center tunnel for access is a hack job smile.gif

seriously, you only need to drill out the spot welds on the side of the tunnel and re-weld....

I think Jeff Bowlsby posted pictures of the repair I did on his Grasshopper car.... welder.gif

Posted by: toon1 Nov 16 2006, 05:32 PM

QUOTE(Mueller @ Nov 16 2006, 03:27 PM) *

cutting the center tunnel for access is a hack job smile.gif

seriously, you only need to drill out the spot welds on the side of the tunnel and re-weld....

I think Jeff Bowlsby posted pictures of the repair I did on his Grasshopper car.... welder.gif

agree.gif that's what I did. pull the clutch and throttle cable before you weld, you'll be sorry if lyou don't.

Ask me how I know!

Posted by: Jeff Bowlsby Nov 16 2006, 09:50 PM

Trek:

Go here to see the carnage of the hard/wrong way and then the easy/right way at the end of the thread.

http://www.914world.com/bbs2/index.php?showtopic=36760&hl=mueller%20clutch%20tube&st=40

biggrin.gif

Posted by: Krieger914 Nov 16 2006, 10:08 PM

Nice plate job for the firewall. I had to make both those repairs as well.

Posted by: SGB Nov 16 2006, 10:37 PM

here is more "insight" courtesy of DD
http://www.pelicanparts.com/techarticles/914_center_tunnel/911_center_tunnel.htm

Posted by: trekkor Nov 16 2006, 10:41 PM

Thanks for the link.

I want to fix this tomorrow.


KT

Posted by: trekkor Nov 16 2006, 10:53 PM

If I do cut a hole, it will be concealed by the center console.

The hole doesn't bother me.

What kills me is, because I don't street drive the car so much anymore, it only breaks down at the track/autocross. headbang.gif


KT

Posted by: trekkor Nov 16 2006, 11:11 PM

My clutch tube is SO loose in there, that when I depressed the clutch pedal the shifter would move. ohmy.gif

I inspected and the top of the clutch tube has been worn to bare metal right under the shifter. It's been loose for quite some time.

At least since the Laguna weekend two months ago.


KT

Posted by: Jeff Bowlsby Nov 16 2006, 11:29 PM

Once you see how easy it is to fix, its way more trouble to cut the hole, and its unecessary. Pull the cable and shifter, locate and drill the holes on the side tunnel wall, weld, reinstall shifter and cable. Done. Very easy.

Posted by: trekkor Nov 16 2006, 11:45 PM

How are you keeping the tube firm against the inner surface of the tunnel before welding?

Mine is all over the place in there. confused24.gif


KT

Posted by: Jeff Bowlsby Nov 17 2006, 12:04 AM

C-Clamp it to the side of the tunnel through the shifter access hole.

Posted by: trekkor Nov 17 2006, 12:10 AM

I'll try that first. Thanks. welder.gif


KT

Posted by: So.Cal.914 Nov 17 2006, 12:15 AM

I heard a good idea for preventive measures, at the fire wall/clutch tube weld

a large fender washer to the firewall over the clutch tube and then to the tube

itself. This reinforces that connection point and spreads the stress out over a

larger area. Just FYI.

Posted by: trekkor Nov 17 2006, 12:29 AM

Yes, I'll be doing something like that, too.


KT

Posted by: JOHNMAN Nov 17 2006, 12:41 AM

I believe at the rear firewall, I used a 1/2" washer with a flat spot ground on it (to fit against the floor seam).

I did the drilled spotweld trick. to secure the front of the tube as well. Real easy fix.

The one location I am sort of concerned with is the weld location between the seats. I couldn't figure out a way to get to that one to reweld it.

The tubes were once welded in 3 spots:

1. At the front of the tube
2. In the middle of the tube
3. At the rear of the tube (firewall).


Posted by: KenH Nov 17 2006, 01:28 AM

In held one in place with a metal cable clamp around the tube and then bolted inside the tunnel with just a bolt & nut coming through the side of the tunnel - no welding.

Ken

Posted by: McMark Nov 17 2006, 03:42 AM

QUOTE(JOHNMAN @ Nov 16 2006, 10:41 PM) *

The tubes were once welded in 3 spots:

1. At the front of the tube
2. In the middle of the tube
3. At the rear of the tube (firewall).


This is true, EXCEPT that they were never welded. No tube is welded to the car. The clutch tube, the engine lid release tube are all brazed. Welding has the potential to protrude into the tube as it melts. Any protrusion into the tube will wear cables FAST! Welding clutch tubes makes me nervous, but it's really the best solution as long as you're careful.

The brazing is also one of the reasons that a fender washer is necessary at the firewall. You can weld over brazing, so in order to repair that section you either have to redo the braze, remove all the brazing material then weld, or use a fender washer that extends beyond the brazing.

Posted by: maf914 Nov 17 2006, 07:30 AM

Mark, Good points about brazing versus welding. idea.gif

Posted by: jasons Nov 17 2006, 10:16 AM

QUOTE(McMark @ Nov 17 2006, 02:42 AM) *


Welding has the potential to protrude into the tube as it melts. Any protrusion into the tube will wear cables FAST! Welding clutch tubes makes me nervous, but it's really the best solution as long as you're careful.

The brazing is also one of the reasons that a fender washer is necessary at the firewall. You can weld over brazing, so in order to repair that section you either have to redo the braze, remove all the brazing material then weld, or use a fender washer that extends beyond the brazing.


agree.gif

I was able to build my weld out far enough past the brazing. Also, I used a piece of flexible copper (the kind for a regrig ice maker) from HD and ran it through the tube to keep the weld from protruding into the tube.

My PO had done a hackjob clutch tube repair with bailing wire. There was already a small hole cut in the center tunnel. I added tabs to the clutch tube and welded the tabs to the floor and wall of the tunnel through the shifter hole and the hole the PO hacked in. I probably could have done it just through the shifter hole and been fine.

Right now the whole deal is untested though. The car is still on jackstands. welder.gif

Posted by: JOHNMAN Nov 17 2006, 01:57 PM

QUOTE
This is true, EXCEPT that they were never welded. No tube is welded to the car. The clutch tube, the engine lid release tube are all brazed. Welding has the potential to protrude into the tube as it melts. Any protrusion into the tube will wear cables FAST! Welding clutch tubes makes me nervous, but it's really the best solution as long as you're careful.

The brazing is also one of the reasons that a fender washer is necessary at the firewall. You can weld over brazing, so in order to repair that section you either have to redo the braze, remove all the brazing material then weld, or use a fender washer that extends beyond the brazing.


You are correct. Those spots are all brazed in place. I still couldn't get to the third spot that everyone seems to ignore.

I forgot. Mine was so loose I could push the tube far enough forward that I ground the brazing off the firewall when I welded my washer in place.

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)