drivetrain noise Fiat 2.0l twin cam - please help

[sean10]

Hi

I have a kitcar powered by a standard road going Fiat twin cam 2.0l and gearbox from a 131.

I have a noise in the drivetrain that I can't diagnose, so I was hoping that someone here with more experience might be able to help.

I recently started the car for the first time in ages, and all appeared OK, but the clutch was seized. I used a brutal method of freeing the clutch, using the engine against the brakes with the clutch depressed. This worked, and after that the clutch seemed to operate OK. However a noise started somewhere in the drivetrain. The noise only occurred when the clutch pedal was up (ie when the clutch was engaged, and driving the gearbox input shaft) even if the car was in neutral. Depressing the clutch made the noise go away.

I took the engine and gearbox out the car, and took the gearbox to a reconditioner, but he said that it was fine. To me the clutch plates look OK, but I'm not an experienced mechanic.

I admit that I'm stumped. Apart from the gearbox, I can't think of any one part in the drivetrain that could give these symptoms. I would greatly appreciate some pointers as to where I should be looking

can anyone help with ideas please?

Regards

Sean

[Walezy]

For me it looks like relase bearing. This makes a weird noise when pedal is relased and all is quiet when you press the pedal. Nothing to be worried about but the replacement will require to take the gearbox out. When you do this check the clutch and if it is worn then replace it(with pressure plate).

[parrish]

Sean,
You mention Kit car and you mention a similar noise to that i had on my 131 when a Strada Abarth engine was incorrectly fitted to a 131 G/Box, have a read of this thread and see if it is of any use.
I would strongly suspect the input shaft bearing, if the G/Box is still out turn the input shaft by hand see if you can feel/hear the front bearing (you shouldnt be able to).
Regards
Steve

http://guy-croft.com/viewtopic.php?f=4& ... nput+shaft

[sean10]

Hello

I had already intended to replace the release bearing, so I will go ahead with that.

I didn't fit the engine and gearbox originally, and have been assuming that they came together out of the same car, but that may not be so. I'll take some careful measurements, and check that the end of the input shaft is correctly engaging with the bearing in the engine.

It will be a few months before the engine and gearbox are back in the car, but I'll let you know the outcome.

Many thanks for the ideas.

Regards

Sean

[Alejoint]

I would strongly suspect the input shaft bearing,

X2 on that. Input shaft and release bearing problems are easily identifyable using a small rule of thumb:

Noise with clutch pedal depressed = Release bearing
Noise present without depressing the pedal, changing pitch and tone with engine RPM = Input shaft bearing

Of course there's also the pilot (or spigot) bearing noise, which when shot will make a very distinct rumble every time the engine crosses the 2000 - 2500 RPM mark (either in gear or in neutral, and regardless of engine load).

[Guy Croft]

Well done all members who contributed here.

That engine and box needs to come out immediately, inspect the crank end brg (spigot brg) and the rel brg.


GC