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Discussion Starter · #1 ·
Well it happened to me too! A few days ago I was driving my 6L Diablo on a short trip in heavy traffic on a local highway when I went to press the clutch the clutch pedal went to the floor with no clutch disengagement. After reading the experience of other Lamborghini owners here I immediately realized I had a case of the well known "Diablo broken clutch rod disease". What a real pain! Fortunately I managed to get it out of 5th gear, freewheel a distance and get into 2nd gear (matching speeds) and babyed it off a ramp into a parking lot. Four hours later I had it home.

Sure enough the next morning I confirmed that was in fact what had happened. I enclose a photograph for others to see in case it happens to them. The rod broke off exactly at the treads. Unfortunately I lost the broken part. Pressing the clutch pedal caused the slave cylinder to dump the rod on the road. Fortunately a friend of mine had a spare new rod so I put that one in (easy to do) and I am up and running again. However it is the same Lamborghini piece and the above could happen to me again any time. Want to insure it will not since I often take 500+ mile trips in the car.

I remembered JRV and/or others were working on a titanium replacement. See:-

http://www.lamborghini-talk.com/vbforum/showthread.php?t=357&page=2&pp=10&highlight=Titanium


Did that ever get made and are they available? How have people found them?

Thinking about the problem I think a relatively easy fix would be as follows:-

One would start 3" long X 1’’ diamater steel bar. Drill a hole ¾ ways through it (along its length) exactly the diameter of the non treaded region of the Lamborghini part having first removed the paint on it. The last ¼ of the bar would then be drilled/treaded to fit the treads on the Lamborghini piece. Then at that same end a grove is cut out to accommodate the clutch leaver with a cross hole to insert the clutch lever bolt. This whole rod then screws into the Lamborghini part fitting tight such that it surrounds and gives strength at the rod tread boundary where it seems to brake. If the titanium rod (above) does/did not work out I will look into this approach. JRV mentions a second brake point on the Lamborghini rod where it is welded. On the replacement rods the weld looks extra thick there. It’s hard to believe that the replacement rods would brake there. Has anybody seen this happen? BTW the new Lamborghini rods still have the narrow region at the treads! You would think their engineers would come up with something better.

Suggestions comments anybody?
 

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i have broken 3 in the past. The stock part is not made for driving. This is the first sign of the clutch itself needing to be replaced. Expect to break another soon.

Have you looked in to aftermarket clutches? i will be replacing mine
 

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Discussion Starter · #5 ·
Clutch Rod in Diablos

No, the early models have a simple design. The rod faces foward and is straight. In 1997 (perhaps earlier) and later they used a larger slave cylinder. This makes depressing the clutch much easier. There was not enough room to face the larger slave cylinder foward so they faced it backwards with a screwball "twisted" weak rod going under the cylinder and up to the clutch lever.

Would like to know what is the arrangement in the Murcielago? Anybody out there take a look.
 

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There was an upgrade from Lamborghini for later diablos. Same design just an upspec in material. You can tell from the colour. Black for old and grey for the upgrade. If the rod keeps breaking than its a sign that your clutch is wearing down.
 

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I had gray rod that broke and have seen others brake as well. What is your thinking as to why a worn cluth will cause the rod to brake? My clutch is fine. Do you feel that a worn clutch will require more force on the pressure plate?
 

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I was told by my Lambo technician that as the clutch plate reaches the end and the rod extends further to compensate for wear, the continued use of the clutch places undue stress on certain parts of rod. You can attempt to strenghthen the rod but according to my technician the real solution is to replace the clutch. I would suggest that you check yours for wear. I do admit though that this is a design flaw on Lambos part
 

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Discussion Starter · #10 ·
More on Clutch Rod

Frankly I have a hard time believing that the few mm difference in movement of the clutch between a new and old clutch would have much difference on the force required to pull them apart. The total travel of the piston in the slave cylinder is well over an inch when you press the brake pedal.

The fact of the matter is that the force to separate the clutch plates by pushing on the bell housing clutch arm is tremendous. One cannot do it by hand without a long lever attached to it. This is I assume because the torque required on the plates is very high to avoid slipping when starting a two ton car.

The original Lamborghini part would be extremely difficult to make because it is not only a bent rod but it is out of plain. The piston driving end is about 5-10 degrees out of plain.

The solution John has above is very smart. It solves the out of plain issue with an end piece welded at an angle, the rod going through the piece itself for strength.

Having experienced the frustration of having a rod go out, the $400 insurance is well worthwhile. It is relatively easy to insert. I will write the installation procedure up on lamboweb.com within the next week or two.

Finally would love to know is the same rod used in 1997+ Diablos the same as in current Murciélagos. If so I think they will experience the same issues in the future. Could somebody look under their car and let us all know.
 

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Our Triple disc clutch that we designed gets rid of this clutch rod problem completely.The clutch rod problem is caused by the bad linkeage design from the factory.Our Triple disc clutch can handle up to 1200 HP becasue one of the reasons that we designed it was for our twin turbo application.The pedal pressure is also softer.It also weighs about 20LBS less so you have 20Lbs less of rotating mass which makes the shifting faster and smoother and less stress on the synchros.

The Murcielago uses a different linkeage so it doesn't have the clutch rod problem.

This issue didn't start with 97 diablos.It started with 95.5 diablos because that's when the factory went with the design that has the clutch rod problem.

If you have any more questions,feel free to give us a call at Hi Tech Exotic Racing.Phone number is 1-888-456-0437.We are also sponsored board member.
 

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Any idea why Lamborghini didn't design a twin or triple plate clutch. Seems like a logical step when you have 600+ Nm of torque.
 

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gtr said:
Any idea why Lamborghini didn't design a twin or triple plate clutch. Seems like a logical step when you have 600+ Nm of torque.
Lamborghini does make twin plate but not for diablos.It's in the Gallardos.The triple disc is relatively new for street use and Lamborghini designed the clutch (with the clutch rod problem) in 1995.
 

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Discussion Starter · #17 ·
Triple clutch etc

Was great to talk to you too Sean. You guys really seem to know your stuff! One idea, it would be of interest to me and I am sure many otheres on this board if you put up a photograph or two of your clutches. Mabye describe what it involves in putting one into a Diablo etc.
 

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I remember watching Clarkson on Top Gear driving the Esprit with triple disc clutch and bitching about how hard it was to drive, demonstrated how easy it was to stall when trying to gently get away.

Does anyone have any experience as to how the multi plate clutch is to drive ??

C'mon, Sean, post the price !!!
 
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