Thanks...So what is turning inside the throwout bearing itself (otherwise, why have a bearing instead of just a steel spacer)?
#2, isnt it? The TO bearing slides up and down on the hub. I cant tell you what number that is in the pis sorry mate, but here is a pic of what I am talking about. Image Unavailable, Please Login
Looks like #19, I think. The TO bearing slides up and down on that hub, shaft #2 goes through that into the clutch plates and shaft #12 goes into flywheel.
Right, but how can that outer shaft #2 turn inside the TO bearing if the TO bearing is seized? I guess I don't understand what two surfaces are turning that require the TO bearing in the first place... There's an inner shaft #12 inside the outer shaft #2, yes? Both go through the TO bearing #32, right? Look, I'm no mechanic, just some DIY'er who has replaced a few parts over the years. I thought that the TO bearing was how the clutch pedal in the cockpit activated the clutch by pressing on the fingers/springs on the clutch pressure plate to disengage the clutch disc from the flywheel...and that would mean that the TO bearing would slide up and down horizontally on the outer shaft...but since the outer shaft is turning doesn't the inside of the TO bearing that holds/touches the outer shaft have to turn, too? Color me puzzled. Just trying to understand the process here.
Anway, if someone could just tell me: does the inner diameter of the 348's throwout bearing spin, or are these solid units?
They slide up and down on the hub, which is a solid. Does not turn. Maybe you and I are looking at the wrong part mate?
Maybe someone mentioned it and I missed it, but the throw-out bearing has to spin (two halves in different directions) because it is not spinning until the clutch s deprerssed and it touches the fork arms on the pressure-plate. The inner half of the TB only slides in and out on the joke, outer half turns on contact. Hope I made sense, Scott
I've color-coded the cross-sectional diagram of the clutch release bearing from the Workshop Manual, which makes it a little easier to understand. The engine "propellor shaft" (yellow) is mated to the crankshaft on one end, and splined onto the flywheel on the other end, so the engine, the propellor shaft, the flywheel, and the pressure plate are always turning at engine speed. The clutch shaft (green) is also turning at engine speed (in the same direction as the propellor shaft, not in different directions) as long as the clutch pedal is NOT depressed. The clutch shaft is mated to the splines on the clutch disc on one end, and geared to drive the transmission on the other end. The clutch release bearing flange (pink) does not rotate - it's bolted onto the transmission case. It's there to provide the location for the actual clutch release bearing assembly. The clutch release bearing is composed of two parts: 1) The bearing support (orange), and 2) The bearing itself (blue). Notice that the support can slide left to right on the flange. The springs hold the bearing in light contact with the fingers of the pressure plate (brown) so that you don't have to pump the clutch pedal in order to engage the clutch. Notice also the seals shown in red, which hold the clutch hydraulic fluid inside the bearing assembly while it is sliding over the flange. On the bearing, you have to remember that this is a cross-section, so there are NOT two bearings (as highlighted in blue), that is only one bearing. The inner race is pressed onto the bearing support and does NOT rotate. The outer race has a "thumb" which extends out to contact the pressure plate fingers. When you press on the clutch pedal, the bearing assembly slides towards the pressure plate, the "thumb" presses in on the "fingers", and the OUTER race can then spin while the INNER race remains stationary. On the car in question here, it appears that the clutch shaft was dragging against the flange (green against pink). When the flange was unbolted from the case, the shaft was released and was able to turn. What was causing this to happen has not yet been determined. Image Unavailable, Please Login
Thank you! So a seized TO Bearing would cause the pressure plate fingers to rub it rather than freely rotate with it...and this would have no ability to seize the clutch or propellor shaft. Also, is it accurate to say that it is internal hydraulic pressure that moves (when desired) the TO Bearing Support left/right on the flange?
The fluid moves the TB in or out on the shaft. (left or right looking at the pic) Note that the TB doesn't actually ride on the shaft that is turning, more like a hollow tube it slides on that the shaft is inside. Hope that helps sir, Scott
Using Hill Engineering pics here ND............. The TO bearing slides up and down on this shaft. (pink one in Jeff's pics.) Green and yellow shafts run through the centre of this. into clutch and flywheel. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Thats right ND. A seized TO bearing would soon chew out the pressure plate fingers and cause chaos in the clutch area.
Sorry guys I've been in Vegas and will be here a few more days. I was thinking the exact same thing with regard to the ring nut. The clutch was released with the engine at the redline so the instantaneous torque could have very easily loosened the nut. What a glorious 400ft smoking burnout it was!! My friends at the custom car shop were hooting, hollering etc. I was not. The flange on the green shaft did make contact with said pink housing and seized. No TO bearring issues etc. So to get at ring nut #14 there is most likely a snap ring that will allow the clutch shaft to be removed, but I have not checked it out yet. Does the trans have to come apart to tighten the nut and do this correctly, or can I pull on the shaft and have the whole assembly pop out from the back of the trans?
You dropped the clutch at redline and laid a 400ft patch in a 16 year old Ferrari that you have owned for a week? That takes some big cojones.
