This is a long post; you may get bored! My 1990, 11,200 mile Testsrossa had a new clutch assembly, thust bearing and flywheel re-grind by a UK Ferrari independent 1800 miles ago. I have never been happy with it:~ The pedal has to be absolutely depressed to the very maximum in order to engage either 1st or reverse gear. It is then still difficult, which indicates to me that there is clutch drag / not fully disengaged. After having driven the car for some time without changing gear; such as on a motorway; when you do then first depress the clutch it is incredibly stiff. After a couple of pushes / pumping the force required returns to normal........... until the next time. Whilst the car is regularly started; it has not been driven on the road for 3 years; which I know is not helpful. I now have more time and as I intend to use it I have entrusted it to another Ferrari independent to investigate the clutch issue. They have stripped it down and advised me that I need a new clutch assembly. They consider that the intermittent stiff pedal is due to the pressure plate spring fingers being dry and without any lubrication. I went to see the dismantled clutch yesterday. There is some blueing / discoloration on the flywheel face and more significantly so on the intermediate ring. The intermediate ring also appears by crude measurement to be slightly distorted / no longer flat. All other parts look OK to me. The posts on this Forum indicate that a clutch can last 50k miles; hence I find it difficult to understand why my car needs a second new clutch at 11,200 miles. In regard to the distorted intermediate plate, a competent machine shop would be able to re-grind this flat. Has anyone had any experience of doing this, and if so, provided that only a small amount of material is removed can the shimming usually be adjusted to accommodate this? Having read past threads, my thoughts are that the most likely cause of the stiff pedal is bad slave cylinder seals / seizing or sticking as the thrust bearing slides along the sleeve. That said, I cannot see a relationship between this and the fact that it only occurs after having driven for a reasonable period of time, without having changed gear. The mechanics view that the stiff pedal is caused by lack of lubrication to the pressure plate fingers is not something that I have previously heard. In my limited experience in fitting clutches I had not been aware that they were lubricated here. My thoughts are that centrifugal force combined with clutch heat would quite quickly remove the lubrication. Any thoughts or suggestions that you guys may have would be appreciated. I feel that I am being presented with the high cost no brain option; without consideration as to what the real cause is, or questioning why a clutch should be replaced after 1800 fairly careful miles. Thanks Greg
Sounds like it was never assembled correctly, or dimensionally, or maybe some wrong pieces were used (there was a serious design change in the SPC) as "The pedal has to be absolutely depressed to the very maximum in order to engage either 1st or reverse gear..." just isn't right. Was the slave cylinder rebuilt? It should've been done based on time (not mileage).
I agree with Steve. It was assembled wrong. I have had to machine parts to get the proper set up height on Testarossa clutches. It is absolutely critical to get the set up height correct. Having to push it to the floor to select a gear is unacceptable. Should never leave the shop in that condition. My recommendation would be to replace the complete clutch assembly and make sure the new one is set up correctly. Grinding a damaged intermediate plate is just asking for issues. Thinner makes it more likely to warp in the future. Getting it perfectly flat and parallel is an absolute must and may not be something a standard machine shop can do. Clamping can easily distort the plate and then it is not flat when removed after machining. Just too many bad possibilities.
Could this be as simple as adjusting the lock nut on the slave cylinder extension screw? Right now you have too much free play in the clutch petal. By moving the nut closer to the arm you will reduce the free play. This assumes the hydraulic system is leak free. Any leaks caused by worn seals will also cause excess free play in the pedal.
My thanks to all for their replies; especially Steve, who I remain indebted to for sharing his outstanding knowledge with me in order to guide me through past electrical problems. Steve I don't think that the slave cylinder was rebuilt - probably still the original seals. Bill Having studied the parts manual, I cannot see where there is an extension screw to adjust slave cylinder stroke? Any further thoughts or advice that anyone has would be appreciated. I am still bemused at an 1800 mile clutch life and what is causing the intermittent pedal stiffness. Thanks Greg
Have to stay with the slave cylinder being the #1 suspect to investigate (and the clutch master cylinder #2 if that doesn't fix it) -- elastometric seals and tight-fitting mechanical joints being stewed in a hydrocarbon fluid for ~30 years with not much use isn't a good situation (especially if the fluid isn't changed uber-regularly). Regardless of the mileage, refreshing the slave cylinder every 10~15 years when the powerplant happens to be out for a major should be on the "should do" list IMO.
As I have installed two of these kits and the pedal effort, pedal height and feel were great and the clutch will far outperform the original Testarossa clutch I would recommend installing the 612 clutch kit in the Testarossa. https://www.hillengineering.co.uk/cck-testarossa
Thanks to all for your replies / advise. Am ordering slave cylinder seals from Hill Engineeering; but still procrastinating as whether to buy new AP Racing (OEM) clutch assembly, or single plate update 512TR assembly from Hill Eng. Once decided; I then have the dilemma of which oil. Having read the past threads; is it still the case that the consensus of opinion favours Redline 75w90ns + 3 ounces of Redline modifier for the limited slip diff? Thanks Greg
My 512 TR has had Mobil 1 most of its life ..no additional modifier etc There isn't any soft metals to worry about And it shifts better than the shell tf stuff when cold Sent from my moto g power using Tapatalk
