Pilot Bearing going bad???

[elevenssc]

Need a little help diagnosing what I hope is a little problem...

My Cuda has a 340 4-spd and at times, while the engine is running and I push in the clutch coasting to a stop, there comes a nasty vibration/noise coming from the trans/engine.  It goes away when I let the clutch out. 

It dosent happen all the time either.  I drive the car most of the time and it happens once every third time out.  The last time out, every time I came to a stop, it happened. 

If I had to guess, I'd pick the pilot bearing. 

Questions...
1) What would a pilot bearing sound like if it were going bad?
2) Would a bad pilot bearing be an intermittent problem?
3) How much of a pain is it to replace the pilot bearing with the engine and trans still in the car?

Thanks in advance for your help...

[ntstlgl1970]

If I had to guess, I'd pick the pilot bearing. 

Questions...
1) What would a pilot bearing sound like if it were going bad?
2) Would a bad pilot bearing be an intermittent problem?
3) How much of a pain is it to replace the pilot bearing with the engine and trans still in the car?

Thanks in advance for your help...

I would check to make sure the exhaust and/or clutch linkage isn't hitting anything first before tearing stuff apart. Look for witness marks where parts may be hitting each other. Also make sure the u-joints are not wiped out. When the driveline goes from a loaded to unloaded state it will tend to highlight u-joint wear.

If all that is good then take a look at the bearing/bushing. On cars with a pilot bearing, usually they will make noise when you first start the car in the morning with the pedal in. But unless you or someone before you has installed a replacement pilot bearing, you have a bronze pilot bushing. Usually those won't make noise even if they are half missing.
It would be unusual for the pilot bearing/bushing to cause a vibration unless the bushing is missing or something. Plan on RnR of the trans and clutch to RnR the pilot bushing. Might be worthwhile to check the runout of the bellhousing (common) and the support sleeve for the throwout bearing for wear issues. Something else to check while in there would be crankshaft end play just to be safe.

[Aussie Challenger]

Need a little help diagnosing what I hope is a little problem...

My Cuda has a 340 4-spd and at times, while the engine is running and I push in the clutch coasting to a stop, there comes a nasty vibration/noise coming from the trans/engine.  It goes away when I let the clutch out. 

It dosent happen all the time either.  I drive the car most of the time and it happens once every third time out.  The last time out, every time I came to a stop, it happened. 

If I had to guess, I'd pick the pilot bearing. 

Questions...
1) What would a pilot bearing sound like if it were going bad?
2) Would a bad pilot bearing be an intermittent problem?
3) How much of a pain is it to replace the pilot bearing with the engine and trans still in the car?

Thanks in advance for your help...

1) Usually a pilot bearing makes a squarking noise, as said above if started in gear with your foot on the clutch.
2) Usually a pilot bush will not cause a problem while in service, however if the clutch has recently been changed or the gearbox removed then if it wasn't lubed it will probably cause a squarking noise.
3)Gearbox and clutch has to be removed.

  I always replace the spigot bush when replacing a clutch and allow extra $ for a new bush when doing a gearbox, cheap insurance so I don't have to replace it at my expense if I don't.   

  I think that you may have a throw out bearing problem based on above info.   

[dutch]

  I think that you may have a throw out bearing problem based on above info.   

I`d say the throw out bearing will make noise with no foot on the clutch...   
the vibration part in the story makes me think pilot bearing...

[Purple73Cuda]

I just replaced the 4 speed and clutch in the 'Cuda. When we pulled the trans. the pilot bushing fell out. It was the wrong bushing (had a flange on it) and it was worn pretty thin. I never heard any abnormal noises or had any vibrations. The worn out pilot bushing caused the front trans. bearing to be ruined.
I got a new pilot bushing at NAPA for around $3.

[Chryco Psycho]

well f the pilot is damaged or missing the front of the shaft wll not center & could cause a vibration when the clutch is released, onc3e the clutch is engaged the clutch could not vibrate but still might not be on center

[elevenssc]

I know the clutch has been replaced in the last 5-7 years.  Not sure if the pilot bushing/bearing was greased at that time

Another data point...I feel the vibration on the clutch pedal and on the pistol grip.  The vibration usually occurs at idle to 1800 rpm when the clutch is disengaged.  The solution is to let the clutch out to stop the noise.

I've got a sneaking suspicion that I'll be cracking into this over the winter.  May be a good excuse to pull the engine/trans so "other" things can be done too...

[dutch]

uh -oh....   I feel a rotisserie job coming up..... 

[Aussie Challenger]

I`d say the throw out bearing will make noise with no foot on the clutch...   
the vibration part in the story makes me think pilot bearing...

  Correctly adjusted the throw out bearing shouldn't be touching the pressure plate fingers. The throw out bearing if faulty will only make a noise when pushed down.

[ShelbyDogg]

I've had to pull my tranny to re-grease the pilot bushing after driving the Woodward Dream cruise in the outside lane. It took about 8 hours to go down 4 miles, then come back. I could have worked my poor clutch 2 thousand times.  Got home and my pilot bearing was howling ( it'll only do it in-gear, with the clutch pushed in).

Pulled the console, shifter, driveshaft, and trans mount. Used my $50 rolling tranny jack from harbor freight, to roll the tranny back enough to get my finger in there with some moly-wheel bearing grease, (leave a dab in the pocket in front of the bushing), then had it back on the road after a couple of hours.

Very easy compared to pulling an auto out, but those are easy too if you have a rolling tranny jack.