Gransport clutch howl

[Oxytorch]

Lately, I've noticed a distinct very brief howl that occurs just as the clutch engages. It only occurs when launching briskly from standstill or taking off up hill. No noise during gentle take off on the flat. No howl when changing gears. Current clutch has seen only about 12000 km (7500 miles).

Any ideas?
Is it the throw out bearing (clutch release bearing)?
If it is, is there any other adverse effect apart from the brief squealing noise?
If it is the throw out bearing, my current thinking is to just keep driving until clutch dies because replacing the throw out bearing requires same amount of work as replacing the clutch.

J

 

[conaero]

If I was to say it sounds like an Owl hooting, would that be your issue per chance?

If so, its the old issue of the spigot bearing spinning in the end of the crank. its nothing to worry about, more of an annoyance.

Maserati UK were replacing them under a recall. Not sure they would do anything about it now as the cars are all too old.

When you get the clutch done, you need to get this replaced with the superseded part.

 

[Oxytorch]

Yes it does sound like a "hoot". And I can sort of feel the vibration of it in my feet when it happens.
I'll google it but just what does the spigot bearing do?

 

[CatmanV2]

Yes it does sound like a "hoot". And I can sort of feel the vibration of it in my feet when it happens.
I'll google it but just what does the spigot bearing do?

Where the drive shaft passes through the bell housing, the spigot bearing is what it rotates in. What's happened is that yours has become loose in the bell housing so the bit which is meant to be fixed is spinning and rubbing against the housing. At least that's my understanding

Part 23 here

http://www.eurospares.co.uk/parts/m...n-pedals/clutch-and-controls-not-for-f1-20137


C

 

[conaero]

Its actually item 9 here Chris, the one you have illustrated is the bellhouse bearing:

http://www.eurospares.co.uk/parts/maserati/4200-coupe/engine/crankshaft-conrods-and-pistons-20117

The spigot is a small bearing that sits in the end of the crank (clutch end) and support the first motion shaft that the clutch slides on.

 

[Oxytorch]

Ok. So the spigot bearing (AKA pilot bearing) allows the transmission input shaft to spin at a different speed to the crankshaft/flywheel when the clutch is disengaged. Therefore, a worn bearing should be noisy only when the clutch is disengaged. (I hear no noise with clutch disengaged). So what's the mechanism of noise as clutch engages?

 

[CatmanV2]

Oops! Apologies

C

 

[conaero]

To confirm it is spigot bearing spinning, engage 1st gear and floor it. If it hoots on drive take up, its the spigot bearing.

 

[midlifecrisis]

I had the same, but I replaced the spigot bearing when I replaced the clutch. Now it's quiet.

 

[CraigWaterman11]

Maserati actually did a Bulletin on the Center Shaft Support Bearing Chris was mentioning (he might of read the post where I posted the bulletin on here some time ago), I haven't seen one on the Spigot bearing yet. Usually, with the Pilot bearing you get that noise when it's a bushing type of pilot bearing but our cars utilize a bearing type of Pilot bearing. If the pilot bearing is sticking in the flywheel you'll also get gear box input rpms while in neutral, and can have problems toggling into reverse because the car is registering gear box rpms. [It's bypassing the clutch friction discs for engagement by transferring rotational force through the pilot bearing and the center support shaft (this is what the clutch transfers the power through as well).

Many times people have their clutches changed out with the pilot bearing etc., the installer (because he has to take out the thrust bearing) re-seats the center shaft support shaft and bearing unknowingly. Then after re-installation it's not an issue again.

There's actually three things that can make a similar noise like this, Pilot bearing (usually the bushing types), the throw out bearing, or for out cars the center shaft support bearing.

Also please don't take it at face Maserati never had one for the Pilot bearing, I'm just saying I never saw it. I work on a lot of things so it's absolutely possible it got around me.

Here is that bulletin again brothers:

 

[CatmanV2]

I do remember that, but I'd not know a pilot bearing from a throw out bearing if they bit me

C

 

[2b1ask1]

Still living with my clutch owl at 71,000 I'll miss it when it goes....