The Stovebolt Site Forums The Shop Area Driveline Noise......clutch area.

For the last 1,000 or so miles I've been living with a noise from the clutch area that sounds just like a very bad throw-out bearing. It's only when the clutch pedal is all the way down. This week I pulled the tranny twice chasing the noise with NO LUCK.

Bit of history, stock 216 engine, 1951 3600. I installed a T5 about 2 years ago that proved to have more issues than I wanted to address, plus the overdrive ratio wasn't sufficient for the stock 4.57 rear gear.

With the original T5 there was "no" clutch or throwout bearing like noise.

The clutch was/is a new Astro Van 11 inch disk with a new NAPA throw-out bearing and the original pressure plate.

Last summer I changed the 1st. T5 out for good WC .72 5th gear T5 and installed a stock rebuild pressure plate.

The second T5's input shaft and throwout bearing collar was modded exactly as I did the 1st T5.

Somewhere about that time the noise started. When I pulled the tranny early this week I could find nothing that looked like it was the noise source. There was a very slight wear mark on the edge of the throwout bearing that I guessed might be due to contact with the clutch fork at full travel. With the hope that was the problem I clearanced it a bit with a grinder. Again, just in case that was the noise source I added a liberal glop of grease to the clutch fork and installed the transmission.

No change, still noise like a bad throwout bearing.

Laying under the truck with it running and the wife operating the clutch, I can't see anything that looks out of place.

The thowout bearing is not spinning in the clutch fork.

So,,,pull the tranny again along with the pressure plate an clutch this time. I really expected to see wear marks on something.....nope, nothing. I did replace the good throwout bearing out of desperation. No change.

So, it's back together and I'm driving it since there is zero noise except for the few seconds the clutch is depressed.

I really don't suspect the pilot shaft bearing since no noise when going down the road.

So, any ideas on what I'm missing?

I am trying to wrap my head around under what condition does the input shaft actually spin inside of the pilot bushing.
I am thinking that it only does so when the clutch pedal is depressed.
If that is so, then you may indeed need to replace the pilot bearing.
Carl

Carl, thanks for the help. I agree on the input shaft only spinning in the pilot bushing when the clutch pedal is depressed. The pilot bushing looks fine and when checked with a spare input shaft felt nice and tight and smooth.

On the pilot bearing, since the input shaft rotates when the clutch pedal is not depressed, it seems to me it would only make noise if bad when the clutch pedal was out, not in.

Am I misreading your comments? If so I apologize and it sure wouldn't be the first time I've done similar.

Ron

added in edit; Just to refresh my clutch understanding I watched this video:



It does a good job of explaining how a clutch and pressure plate work, unfortunately I'm still at a loss on explaining and fixing my noise.

Well, after much pondering I May be on the verge of something. I failed to mention that when my "old stock" rebuilt original diaphragm pressure plate plate showed up, some of the rollers or pins were out of position and the diaphragm was askew. I don't really recall exactly what I did, but was able to get things back in position and looking exactly like the original pressure plate.

I'm now wondering if I overlooked something with the pressure plate. The check would be to reinstall the original....for some reason I'm not feeling super motivated at this point since I'm still guessing.

Is it a growling noise?
I had a growling noise after about 400 miles with a brand new release bearing. Growling only occurred at the red light. Called the vendor who sold it to me. He says all release bearings these days are imported. The manufacturers use the least amount of grease possible inside the bearings.

I had my T5 out for other reasons and took that opportunity to inspect the release bearing. I removed the rear seal and found almost zero grease inside. I packed it with grease and put the seal back. Growling noise is gone. Worth a look no matter what the current noise is from.

If your pressure plate is the original style it has 4 lugs on the plate that guide it in the cover. These guides wear quite bad.
When worn the plate will shake in the cover when the plate is not pressed against the disc. This can give you a very noticeable noise when the clutch pedal is depressed.
If you can shake the pressure plate while it is out, and you hear anything, look at the guide lugs.

Pre'68Dave, you comments tweaked my memory and it was one or some of the 4 lugs you mentioned that were out of place on my rebuild PP when it arrived. I mistakenly said rollers were out of place earlier.

Wish I'd made a few pics of the pp when I got it, would sure make it easier to see what issues it had. But as mentioned, I don't recall it being much of a challenge to put things back in place.

I wonder if the rebuilder failed to replace worn lugs, hence they were not tight and shifted during shipping. If so you may have well nailed the root cause of my noise.

Lugnutz, your throwout bearing thread did cause me to suspect my fairly new tb. However I changed it out with no improvement.

In researching this I see there are only 3 lugs, see picture.

Dave, Thank you for the help and research. Just thinking out loud here, if worn lugs are the problem, would you venture a guess on how serious an issue it is.

On a scale of 1 to 10 with 10 being deal with it in the next 100 miles and 1 being take care of it when convent.

Again, just having a conversation....no worries if it flies apart a mile down the road.

My gut is it's really not a major issue, just a nuisance due to the rattle.

I think it is more of a nuisance than a problem.