Thrush Bearing!! I'm getting tired of this!

Speaking of which, wise, have you adjusted the clutch pedal according to the manual? I'm wondering if perhaps it's riding the bearing up against the pressure plate or something? Also, in just looking through the manual real quick (before heading out the door to dinner), it appeared there was something about having to calculate some spacers. I am not sure if they were talking about something relating to the height of the installed throw out bearing or not, but it may be worth a second look. I tried to see if there was any spec regarding a clearance between the face of the thrust bearing (a.k.a. the throw out bearing - no pun intended and the pressure plate, but couldn't find anything. It appears it rides on there and constantly spins. Have you changed anything in there with regard to the clutch, etc? I seem to remember an extensive post from you where you did a clutch replacement a while back no?

I still think temperature may be a factor in all this - but that's just a guess.

Ray

 

^ I'm def. no mech, but that's my thinking too. It is not as precise as the OP wants to believe...thinking slightly off, makes for a > wear factor.

If honestly doing 140+ for hours [hmmm ] I'm starting to fear for his tires now, let alone all the mechanical bits claimed to be up to spec.

 

My, my. Getting kind of emotional about this whole thing aren't you?

A little clearer head will go a long way.

 

Absolutely not, but you know, on this design, it wouldn't matter much. All you'd get is some slipping if you rested on it enough, and you'd wear out your disc eventually. It would, however, create more heat, if I just rested it on there and drove for hundreds of miles. That would be a cause, but definately not the case with me. Actually, I went a little further with this idea and made those springs that press it against the pressure plate, actually pull it off the PP by anchoring them with roll pins and making a stop. But that just got too complicated and would probably mess with the pressures those seals could handle both in the clutch master and the thrust bearing.

 

That's just the problem. It has two springs that make SURE it's pressed up against there. I believe they're there to assist in quick shifting. This is an F1 inspired design. It has to be temperature. But, what can you do about temperature? Not much. Drive slowly??? Not possible. Make it serviceable or flex plate it like the German cars are. The first picture is a 1983 design of the Porsche 944 throw out bearing. I first noticed it then, and thought this was the cool way to deal with the adjustment problem. This was about near the start of the hydraulic clutch era. The second picture is 23 years later, the 911 Turbo uses the same concept to keep that Throw-out bearing off the pressure plate. This Ferrari design serves a purpose, that is to shift quickly. In the 6-speed manual, it's not really all about how fast I shift.
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Ok, fair enough mate.

Sorry I cant help ya with any other suggestions.

 

Progress Update: My grease fitting thrust bearing just passed the mileage of the two previous thrust bearings and is doing so without a peep. Yeah!!! It will last forever!!!!! And the clutch disc and pressure plate have gone 41K so far.

 

Good to hear brother!

 

Your solution to add more grease is a novel idea, but lets be clear here its a work around to a problem somewhere else in the system and could cause problems later on. It reminds me of Microsoft patching their software to allow bugs in other peoples software to still work properly. Absolutely yes it may do the job but there could be other side effects yet to transpire such as total system failure.

Total failure is absolutely not something I'd like to contemplate at 140mph and in the middle of the desert! I definately be looking for the cause of the original behaviour which most definately is not normal, even without hills uprated bearings.

Typical causes of release bearing failure;

1. Normal Wear & Tear
2. Misassembly
3. Misalignment
4. F1 system failing to fully release the clutch (or riding clutch in manual car)
5. Overloading
6. Dirt contamination
7. Manufacturing defects.

Ofcourse if your happy to take the risk that something else may fail later on continue pumping grease. Its obviously your choice, your car. Not sure everyone else would agree with you but hey, its a free country and everyone has the right to their own opinions.

-T

 

Please be specific. Something else will fail? And the whole system will fail? You mean like a nuclear meltdown. What are you talking about? The thrust bearing slides onto a shaft that only goes on one way with no adjustments or alignments. Assembly-wise, the springs are there and the bolts holding the thrust bearing on, are there. -Riding the clutch wouldn't really matter much because like I said earlier, the thrust bearing is pressed, with springs, to ride on the pressure plate anyway. I don't ride the clutch at all, for the record. Actually, I use the clutch as little as possible. -Dirt contamination is virtually close to impossible because not only does the bearing have grease seals, it is also pressed and encased in a tough alloyed aluminum housing that Hill has so nicely upgraded (objective and non-bias conclusion). -Manufacturing defects??? Possible, however, why would it last 17,000 before any sign of what sounds like a dry bearing condition? -Overloading? Well, I never press the bearing more that a couple of seconds to shift only; at red lights, always in neutral. And I've already experienced total system failure, that's exactly what I'm trying to overcome, which in this case is that the bearing locks up and screeches on the pressure plate. (After a couple of thousand miles of periodic noisy bearing) And honestly, I drove it home like that because I know the worst it could do is scratch up the tips of the pressure plate splines. The damage was so little, though, that I used the same pressure plate. The bearing clutch system is a simple mechanical design; it's not some mysterious electronic micro circuitry that could result in a major catastrophe. It's simple physics. I like being able to understand exactly what’s going on under my hood. When I press that clutch, it’s nice to know exactly what forces are working with me. I insist on assembling my brakes myself and tightening the lug nuts myself also, because when I drive fast, my life and the life of others depends on it. ...P.S. I really like the signature quote at the end of your responses. “Strive for perfection in everything we do. Take the best that exists and make it better. When it does not exist, design it. Accept nothing nearly right or good enough.
Henry Royce

 

Good news!

Damn, you really drive the car alot

Enjoy

 

Call it a band-aid if you like but I admire the ingenuity and regardless of cause it seems that you've found a solution that works for YOU! Well done!
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It seems like my car has the exact problem you are describing here...
It all started a while back when during shifting at high RPM (above 7k) the clutch pedal would drop slightly and would operate again normally when shifting at lower RPM...
I didn't mind too much, since at high RPM shifts you don't care much about how progressive the clutch is... You just depress the clutch all the away and release quickly after the shift...
At low RPM my clutch was working just fine... No clutch slippage at all...

I took my car to the dealer for a major service last month (see separate thread on the mistakes the dealer made with the timing belts, now fixed !!!) and the service manager identified the problem as faulty o-rings around the thrust bearing of the clutch that caused the clutch not to fully return after high RPM changes... The service manager suggested that in the near future we drop the transmission to remove clutch assembly and correct the problem... change the clutch disk as well since the transmission would be dropped...

Today, after driving the car for 1 hour I realized that the problem had started to occur at low RPM as well, with first and second gear becoming too difficult to engage... It seemed like the clutch was not fully decoupling and was not allowing the gearbox to operate normally... It took extra effort to even shift from gear to neutral...

Therefore, it seems like I will not be getting away from a clutch / bearing change...

Do you think changing the o-rings around the thrust bearing (and maybe even the thrust bearing itself) will solve the problem ?

Does anyone have a rough estimate of bearing, clutch disk, etc
Do you also change mass flywheel ?

Thanks !!!

 

By the way, forgot to mention that my car is 6-speed manual 360 Modena 2002 model

 

Well it's either as the dealer said, the bearing is sticking on it's seals, or (also VERY common) a leaky clutch bleed block. As it's got so much worse so quickly i'd say the latter of the two. Have a look under the back of the car at the undershield and see if there's any browny coloured fluid dripping out......

 

MD, I had very similar issues to those you describe, mostly the high RPM shift but occasionally also at stop lights. I suspected that it was either the thrust bearing or master cylinder. On checking the master I found a small amount of fluid (visible when I inspected the rod from the pedal to the cylinder) so I ordered that part on the basis it was relatively cheap and easy to install.

Getting a good pedal after replacement was next to impossible and the original (high RPM shifting problem persisted). My guess is that while there was a small leak in the master this was not the problem.

After much gnashing of teeth and further investigation we did find a problem. The supply feed pipe from the fluid reservoir to the clutch master was badly routed and had a kink. Once we re-routed it the problem eased off dramatically.

Since then (18 months or more) I occasionally got a slight sensation of the same problem and what I did was bleed the system just a small bit. Pump twenty times, hold pedal, crack off the bleed nipple, lock as soon as fluid stops pushing out, lock nipple and repeat x 4 or 5 times.

I was somewhat resigned to doing a full clutch job but the above has it sorted and I haven't had to go near it for 12 months now. My advice to you would be to spend a good couple of hours or more flushing, bleeding the system and investigating all round. Replacement is expensive and it's shame to do it when maybe only half way through the life of the clutch.

Best of luck!

 

Not sure how long the F1 TO bearing was engineered to last, however, just like everything in this world-----------it wears out with time. With that said, it would be wise to change out the TO bearing during clutch changes.

I give you an A+ for thinking out of the box. Not sure like others are saying what the true problem is------------however, I do know that these TO bearings will get sticky and catch intermittently sometimes before clutch is needed to be replaced (on the F1 systems).

My concern would be that "over" lubricating would be a problem. It does not take much.

The TO bearing is over looked alot of the times when trying to set the PIS or re-learn on the F1 systems.


Good Luck

greyhair

 

MD355, If it were me I would change out / replace all components envolved during your clutch change.

You can take a chance on replacing the seals on the TO bearing which may be the problem if you are doing the work yourself (if costs are a problem).

 

MD, I had the same problem in my 6 speed. It was diagnosed as a clutch issue. The dealer replace the entire clutch including the t/o bearing and the problem went away. I did this at 27k miles.

 

Did anybody notice in the photo that the middle o ring seal in the bearing was broken, was it broken on removal or on installation?

 

It is not broken and is delivered as is. It is not a seal but a guide to center the bearing on the shaft.

 

+1

Of course, you'll use very little grease and very low frequency....

Good Luck,
Vincenzo

 

No need to be such ******! Calm down. So Yoda of T/O bearings, enlighten all us mere mortals as to the possible (or most plausible) reasons this could/is happening. Pretty sure people come to this forum for something other then your insults

 

UPDATE :

I took my car to the Ferrari specialist last Monday and told him about the 5 possible causes of the clutch problem as listed on this forum :
1) Air in the line of the fluid of the clutch system
2) Leak in the system
3) Faulty Clutch Master / Slave cylinder
4) Kink in the return lines from the clutch reservoir
5) Sticky Clutch Bearing

The first four are the cheapest to repair, the 5th requiring transmission removal and once you're there new clutch kit as well !

After inspecting the car he diagnosed that the brake / clutch fluids had never been changed !!!

I have been taking my car to the dealer for 5 years now, performing annual services and 2 major services and the fluids were in such a bad condition that he changed them and removed the air from the system too...

He also found some other things like low coolant level (remind you, I got my car back last month from a major service at the dealer) , clogged disc brake holes (???) , minor oil leak from the camshaft cover patched with silicone, and disconnected low-brake-pad indicator lines from the front brake pads...

He tried the car and told me that the improvement was not that significant so he will be replacing the master clutch cylinder next (relatively cheap fix if it works)...

He told me he wants to explore every possible fix before removing transmission and going for the bearing...

When I told him about the kinked line of the reservoir, he said that this comes for the factory and it is very difficult for find...

Can you elaborate on the above ? How / where did you find it ?


I hope the master clutch cylinder does the work...

 

What FerrariDublin was referring to can be seen behind the panel in the front luggage compartment in front of the windshield. You need to remove the carpeted panel on which the tire inflator is located in the front trunk. Behind this is the clutch master cylinder, brake reservior, steering rack etc. There is a hose that leads from the brake master cylinder to the clutch master cylinder. When this gets "bent" or has a kink in it like a garden hose, the brake fluid cannot get to the clutch and it becomes starved for fluid, thus diminishing the clutch action. Your mechanic will observe this when he checks out the clutch master cylinder. Takes about 15 minutes to remove the panel. Best wishes in the matter!

BTW, Once a car is out of warranty, I NEVER take a car to a stealership... err.. I mean dealership. Too expensive for the work that gets done and I've had many do work that was not needed (before i knew better of course). ;-) Sounds like you're on the right path.