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Clutch failure

Posted: Sun Jan 16, 2011 12:12 pm
by jmvv
I had to drive to Pretoria yesterday for some business. Petrus ran very well as always. I enjoyed the 1500 box's short gearing on pulloffs down Potgieter Street (some people get very cheesed off when an old fart in an old Beetle show them a clean pair of heels from the robots)

On completion of my business, when I started Petrus again an ominous clattering sound was emitted when the engine fired. "Fook, Bearings" I thought, but realised that the noise only appeared when I depressed the clutch.

Then it dawned on me, something in the clutch had died.

I did not have time to wait for Outsurance's recovery (very handy if you drive an old car), so I decided to drive it cluchless and change on revs.

Snicked it into first and started the engine - He jerked into life and trundled out the parking area. It was a bit of a mission to join the traffic as I had to kill the engine, engage first, wait for a suitable gap and hit the starter button (ignition switch is only for decorative purposes on this one). Join the traffic on starter power and accelerate away as the engine fires.

Now I had to judge the traffic flow as I had to kill the engine to engage first if I got stopped at atraffic light. Had to do that on two occasions.

Coming up Schubart Street, I had to pull of on the starter at the first robot, accelerate to a suitable speed in first, slightly come of the power and simultanously slip it into neutral, then blip the throttle and at the right engine speed (approx 1500 rpm) gently slip it into second. If you get the feel for it, the gear engage without any grinding.(Thank you for the good synchros, Dr Porche)

By sticking to about 50 kph, I managed to time the synchronising of the traffic lights perfectly and only had to stop at the beginning of Potgieter Street again.

Repeated the starter pulloff procedure and held it in third up to the beginning of the freeway, where I snicked into fourth and I was on my way back to Centurion.

Coming off the highway required a reverse of the procedure to go down the gears.

Slow down sufficiently, come off the power, slip it into neutral, blip the throttle, snick it into third; repeat to get second and eventually first. Timed the robot right and managed to get back to the shop without further hassles.

So Petrus is on sick leave until I can find the time to pull the engine. (my car goes on the back burner as I have a customer's racing 1975 Cortina Big Six in the shop to sort out this week)

As for the clutchless gearchange, all I can say is "a misspent youth is better by far than a wise and productive old age" (Meatloaf)

Re: Clutch failure

Posted: Sun Jan 16, 2011 3:53 pm
by hitlers revenge
Glad you made it home.

That happened to me a few months back. The only difference is that I changed gears without my foot on the acc. pedal. Every time I changed a gear , I took my foot off the acc. pedal and had smooth gear changes.

Re: Clutch failure

Posted: Sun Jan 16, 2011 9:37 pm
by fig
Nice story. BTDT. Clutchless gearchange is a very useful skill if you drive old cars. :hangloose:

Re: Clutch failure

Posted: Mon Jan 17, 2011 10:21 am
by calooker
Could be something as simple as thrust bearing clips letting go, good luck.

Re: Clutch failure

Posted: Thu Jan 27, 2011 10:42 am
by jmvv
It turned out to be the tip of the clutch fork that broke off allowing the release bearing to rotate.

Image

See the image on the right.

I wonder how many million clutch actions it take to wear the realease bearing grooves like that when compared to the new shaft on the right

So, as I was in the area, I got a new fork from Volkspares in Jet Park.

Back home, the fun begins.

I took out the old shaft and bush (totally destroing the bush in the process - for some silly reason, the bush did not want to leave its workplace of 40 odd years)

Volkspares Pretoria supplied my with a clutch repair kit containing the necessary bushes, springs and seals.

So with the new bushes installed, I try to install the new fork. No friggin way would it go in to the starter side bush.

Now the self doubt kreeps in. "What did you F###k up?" "It's only one shaft with two bushes - idiot"

With the big hammer urge supressed, I took a good look at the fork and found that the shaft was bent between the two arms. It was caused by an identification number stamped into the shaft during manufacture.

Volkspares exchanged it for a new STRAIGHT shaft. This went in like a charm and happiness was restored.

The clutch and pressure plate were replaced about 10000km previously, so that stayed in.

With the engine replaced and the clutch adjusted properly, we were mobile again