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It’s been almost a year since our Caterham has put wheels on the street. Last June while driving the Seven home on my evening commute through the 91 Freeway work zone in downtown Riverside, traffic predictably came to a halt. I pushed in the clutch pedal and tugged on the gear lever, and the lever would not budge! What the *%&[email protected]! I tried again and pulled really hard and this time got the gearbox into neutral. One problem solved, but a much larger problem loomed: what to do when traffic began the usual stop and start crawl? Due to the construction on this section of freeway, there was no shoulder. In a mild panic, I pushed in the clutch and was able, with loud noises of protest from the gearbox, to engage third gear. Using this, I got to an off-ramp, and with only a few intersection infractions later, made it home.
At first I thought the clutch master cylinder had failed and would not hold the clutch open. I had re-built the cylinder about 40,000 miles earlier and was suspicious of its condition due to a few earlier instances at stop lights where it was hard to get the car into first gear. Not an uncommon occurrence with clutch hydraulics. So I bought a new Girling cylinder from Summit Racing and installed it. For a brief moment I thought success, but a quick drive around the block proved me wrong. Major surgery was now indicated.
With the engine and trans pulled out of the chassis, I unbolted the bellhousing from the engine, and laying in the bottom of the bellhousing was my first piece of evidence; a short and twisted piece of heavy spring steel. Next I unbolted the pressure plate from the flywheel and there in all its dusty ground up glory lay the remainder of one of the clutch disc cushion springs. It had migrated out of its clutch disc holder. Not surprisingly, the opposite spring was just about ready to join it. The clutch disc and pressure plate were OEM Ford parts. At this point, they had also been in service for about 40,000 miles, admittedly including several AROSC enduro races and a number of other track events.
The last time I replaced the clutch, Jon Nelson at Caterham USA advised that I should have taken the opportunity to upgrade to a lighter flywheel. So now, this was my opportunity and I gave Jon a call. Jon is no longer the US distributor, but he said that he still has considerable inventory of Caterham parts in his garage warehouse. He suggested I check to see if Fidanza still manufactures a flywheel for the Zetec, but mentioned there were some dimensional issues when fitting one to a Zetec with flywheel/clutch sourced from the Ford Contour parts bin. I found the Fidanza flywheel, part no. 186991 and ordered one, and like Jon warned, the starter ring was in a slightly different plane than the steel flywheel that I had been using. However dimensionally, the timing ring was positioned okay, and the clutch mounting face was the same. Another call to Jon and he happened to have a starter that will work. Success!
Because this was the third time I’ve had a Ford OEM clutch failure, I wanted to upgrade to something more robust. I found Clutch Masters, located in Rialto, only a few minutes away from my home in Riverside. These guys know their business, and when I took my old clutch assembly to them, they pointed out several things that caused the problems. Most significantly, it was the design of the diaphragm finger ends for interfacing with the center shaft throw-out bearing. The ends of the fingers should be a raised curve, and not cut straight. I ordered a Stage 1 racing clutch from them and luckily the stack-up from the flywheel is identical to that of the OEM assembly. No shimming is necessary for the throw-out bearing.
Finally, this seemed like a good occasion to replace the flywheel retention bolts. I ordered a set from Automotive Racing Products (ARP). They have twelve point heads and fit perfectly onto the flat mounting area of the Fidanza flywheel (something the stock bolts heads were too large for). Now I have all the necessary parts for the upgrade and the re-build has begun. The journey back to life!
Best wishes,
At first I thought the clutch master cylinder had failed and would not hold the clutch open. I had re-built the cylinder about 40,000 miles earlier and was suspicious of its condition due to a few earlier instances at stop lights where it was hard to get the car into first gear. Not an uncommon occurrence with clutch hydraulics. So I bought a new Girling cylinder from Summit Racing and installed it. For a brief moment I thought success, but a quick drive around the block proved me wrong. Major surgery was now indicated.
With the engine and trans pulled out of the chassis, I unbolted the bellhousing from the engine, and laying in the bottom of the bellhousing was my first piece of evidence; a short and twisted piece of heavy spring steel. Next I unbolted the pressure plate from the flywheel and there in all its dusty ground up glory lay the remainder of one of the clutch disc cushion springs. It had migrated out of its clutch disc holder. Not surprisingly, the opposite spring was just about ready to join it. The clutch disc and pressure plate were OEM Ford parts. At this point, they had also been in service for about 40,000 miles, admittedly including several AROSC enduro races and a number of other track events.
The last time I replaced the clutch, Jon Nelson at Caterham USA advised that I should have taken the opportunity to upgrade to a lighter flywheel. So now, this was my opportunity and I gave Jon a call. Jon is no longer the US distributor, but he said that he still has considerable inventory of Caterham parts in his garage warehouse. He suggested I check to see if Fidanza still manufactures a flywheel for the Zetec, but mentioned there were some dimensional issues when fitting one to a Zetec with flywheel/clutch sourced from the Ford Contour parts bin. I found the Fidanza flywheel, part no. 186991 and ordered one, and like Jon warned, the starter ring was in a slightly different plane than the steel flywheel that I had been using. However dimensionally, the timing ring was positioned okay, and the clutch mounting face was the same. Another call to Jon and he happened to have a starter that will work. Success!
Because this was the third time I’ve had a Ford OEM clutch failure, I wanted to upgrade to something more robust. I found Clutch Masters, located in Rialto, only a few minutes away from my home in Riverside. These guys know their business, and when I took my old clutch assembly to them, they pointed out several things that caused the problems. Most significantly, it was the design of the diaphragm finger ends for interfacing with the center shaft throw-out bearing. The ends of the fingers should be a raised curve, and not cut straight. I ordered a Stage 1 racing clutch from them and luckily the stack-up from the flywheel is identical to that of the OEM assembly. No shimming is necessary for the throw-out bearing.
Finally, this seemed like a good occasion to replace the flywheel retention bolts. I ordered a set from Automotive Racing Products (ARP). They have twelve point heads and fit perfectly onto the flat mounting area of the Fidanza flywheel (something the stock bolts heads were too large for). Now I have all the necessary parts for the upgrade and the re-build has begun. The journey back to life!
Best wishes,
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