Whilst trying to find my engine rattle at around 1750 rpm, I removed the a/c belt and the alt/water pump belt to try and isolate the noise. With both belts off and the offside rear of the car in the air, after only about a minute of running the engine, a "pop" occurred and the engine ran very smooth as if there was no resistance to it running. I shut the engine down for a closer look. I think I found the source of my rattle - a heat shield between the fuel tank and engine resting on the water pump pulley. I wanted to confirm this as the problem and went to start the engine. The starter seems like it engages then seems to turn but does not turn the engine. I have now removed the starter (which seems fine) but the flywheel rotates freely with the gears in neutral. When I put the car in gear, the flywheel then has some resistance suggesting that the gears engage. The problem seems to be that there is no connection between the flywheel and engine because it is free to rotate with neutral selected. Anyone have any ideas? Seems like something has broken loose to me. Clutch area or gearbox?
Does not sound good mate........... Could have a broken gearbox output shaft perhaps? Maybe a stripped spline? But I am thinking more like it is broken mate. You should remove the clutch pumpkin and investigate my friend. Image Unavailable, Please Login Image Unavailable, Please Login
Thanks Pap for the reply. Because of the sudden change in engine note/smoothness, my fear is that something has broken. The engine was less than 2000 rpm when it happened so there was no load to speak of. It seems like the connection though between engine and gearbox because with it in gear it seems like it is engaging i.e. resistance. Perhaps that shaft is the problem and is that something that can be changed with the bellhousing off or is it a gearbox strip?
I can honestly tell you that I would not have a clue how that shaft comes out Terry. I have not had the pleasure of playing with my gearbox yet or this shaft in question. But...........I am sure a fellow Fchatter will soon chime in and let you know of their experience with it and how it all comes apart. I could take a wild guess and say the shaft comes out, after you remove the T/O bearing and T/O bearing shaft. 4 bolts to remove that from the gearbox. The shaft may come out when that is remove. But best to wait till someone that has done this job before, chimes in here to help you out or give some pointers. I am very interested on what happened to your car mate. Hopefully it will not be a too painful job to do.
Just pulled the housing off and as you see, sheared shaft. BTW, the car was in nuetral, no load, less than 2k rpm when it broke. No loud crack or bang, just a pop. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Okay, I'm trying to learn. Someone explain to me exactly what I'm looking at and what's wrong with it.
In picture 2 and 3 you are looking into the clutch/flywheel assy. The shaft in the centre should be attached to the end of the shaft shown in the other pictures. i.e. the inner shaft should be protruding out from the outer shaft in picture one.
The damage was done long before it finally broke. There are a lot of parts to remove before you get to that. It's the "Bad Thing", sorry to see it.
Looks like it has been cracked for a while around the outer edge. Is there any reason behind this shaft failure? Wear and tear? Hard launches/abuse? Lots of track work? I have never seen this before, so I am just curious if it is a common thing?
I've seen/heard warnings on that very thing for driving Ferraris at high rpms before the gear oil and output shaft are fully up to operating temps...that the output shaft can weaken/break over time.
Cool!!! ok not so cool...*ahem*...Interesting!!! If you want send it to me, I'll analyze the fracture in the electron microscope (sure beats looking at the usual broken valve springs! ) I agree with you astute guys, looks like there was a fatigue crack growing for a while before it let loose. It is strange to happen under very low load...
Looks like you lost the splined end of the propellor shaft (part #15 in the drawing). It connects the crankshaft to the flywheel. As slender and long as this part is, considering what is expected of it every time someone tries to smoke the tires, I am surprised that it doesn't break more often. Once you have it out, look carefully. You may see evidence of twisting. Image Unavailable, Please Login
That was a thought of mine but the gearbox was not in gear so no drive to the wheels so I do not understand the logic. If this can happen with one wheel off the ground then beware.
Terry, I really hope your transmission is OK, but there has to be some reason why the shaft snapped. I'm not sure about the 355, but on the 348, the transmission oil pump is driven off the left end of the mainshaft, which is turning when the engine is turning and the clutch pedal is NOT depressed. I wonder if raising the left (offside/RHD car?) side of the car off the ground drains the transmission fluid away from the oil pump enough to starve the pump?? It still seems like there should be enough "splash lubrication" to keep things safe in the short term. Have you tried turning the transmission using the clutch driven shaft, with the lever in neutral?
Thanks Jeff for the comments. I will look a little more tonight and update the thread. I understand from talking around that it is not unknown, although unusual for these shafts to break.
It looks like a case of removing the gearbox and removing the old shaft from the front of the box (engine side) and re-installing a new one. I understand not difficult once the box is removed. New shaft about £1k, unless you want to trust a used one for a lot less.
If you go to all that trouble to replace that shaft.........I would be inclined to fit a new shaft. Not worth refitting a used shaft, then having it break on you 6 months down the track. Pull it apart back again........**** that!! I hate doing jobs twice!!
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