1SLwLS1

iTrader: (6)

When the car is sitting still, at a light per say, with the transmission in neutral, and the clutch engaged (read: foot off of the clutch pedal), I notice a pretty heavy vibration in the shifter **** as well as an occasional chatter-like sound coming from the transmission. It is hard to describe it as it is pretty faint and I can hardly hear it with the air and radio off with just the engine idling.

When I disengage the clutch (read: foot on the clutch pedal), the vibration in the transmission immediately ceases (aside from the normal rumbling of a cammed 408) and the noise goes away.

A few noteworthy mods - Energy Suspension Polyurethane Transmission Mount, Energy Suspension Polyurethane Engine Mounts, Monster Stage IV Clutch, GM or Monster Steel Flywheel, GM Slave Cylinder, Tick Master Cylinder, MGW Shifter.

The clutch/flywheel/slave/MC were installed around mid-March of 2009. They haven't been misbehaving more than usual. The engine mounts went in around mid-July of 2009. The transmission mount went in about 4 weeks ago and the shifter was installed 2 weeks ago.

I am a little baffled. The mustang guy in me says TOB/Slave, as would be the case with cable driven clutches in Mustangs, and all of the problems I had with that setup, while the fearful and paranoid F-body owner in me says, you have a hydraulic setup so yours transmission is f**ked.

Ideas?

thesource

iTrader: (60)

Its gear chatter from the rough idle of the camshaft.

1SLwLS1

iTrader: (6)

Is this normal or an indication of impending doom...?

SPEC-01

iTrader: (2)

Is this noise and vibration a relatively new issue? When did it start? Lets look at the basics and see if we can nail it down.

1SLwLS1

iTrader: (6)

I would say this could of started around the time I broke my driveshaft, about 6-8 weeks ago, at the earliest.

thesource

iTrader: (60)

Its normal as long as its making noise due to the idle of the engine. If the noise goes away with a little bit of throttle in neutral, its the cam.

1SLwLS1

iTrader: (6)

I will verify in an hour, thanks thus far.

1SLwLS1

iTrader: (6)

The noise did NOT appear to go away as I revved the engine. I recorded (2) videos for reference. The darker one is louder, while the brighter one is quieter.

Darker Video
http://www.youtube.com/watch?v=am10N6hjRH4
Description: "Chattering/vibration from transmission in neutral with the clutch engaged (read: foot is off of the clutch pedal). The noise completely stops when I dis-engage the clutch (read: foot on the clutch pedal). Also, I did NOT press the clutch pedal during this video. See other video for reference. The noise does not appear to go away once revved either."



Brighter Video
http://www.youtube.com/watch?v=biIBEd0HWkI
Description: "Chattering/vibration from transmission in neutral with the clutch engaged (read: foot is off of the clutch pedal). The noise completely stops when I dis-engage the clutch (read: foot on the clutch pedal). The noise does not appear to go away once revved either.

At 38 seconds, I press the clutch pedal, at 40 seconds, I release.
At 46 seconds, I press the clutch pedal, at 48 seconds, I release.

You can fairly easily hear the noise go away, it doesn't help that the engine is loping in the background (sorry I closed the cutout, too)."

Now, armed with more evidence and clues, what do you guys think...?

thesource

iTrader: (60)

I can hear it in the first video good. You don't hear any noises in 1st-3rd gear driving? What about 5th & 6th gear while driving?

1SLwLS1

iTrader: (6)

I cannot hear it in 1st-4th, if it is there, but in 5th & 6th this morning I hear a kind of whining noise. Almost sounded like electrical interference through the speakers, but I turned the radio off and the noise persisted. I then applied the clutch, and it stopped.

thesource

iTrader: (60)

Tough to say. How long has it been since you checked the fluid level in the transmission? If it was gear chatter, it should clear up around 2,000 rpms in neutral unless the camshaft is really big.

1SLwLS1

iTrader: (6)

It has been since March when I last replaced/checked the transmission fluid. I picked up some fluid this morning on my way in to work, thinking the same thing you are, so I'll go ahead and swap it out anyway.

The cam is a MS4 in a 408.

thesource

iTrader: (60)

That camshaft in a 408 cid engine should be smoothing out around 2200 rpms. You shouldn't be hearing gear chatter in neutral above probably 1700 rpms maybe even as low as 1500 rpm. I have a slightly smaller camshaft in my 393W Ford with a T56 behind it and I get gear chatter until about 1500 rpms only in neutral.

I would go drive it and listen to it really close. Listen for whine or knocking sound in 1st-3rd and then again in 5th & 6th. 4th gear is going to be quiet.

1SLwLS1

iTrader: (6)

I'll give it a shot @ lunch.

1SLwLS1

iTrader: (6)

The neutral rev thing is hard to nail down above 1.7-1.8K revs, the engine just makes too much noise and the interior of an f-body leaves a lot to be desired in terms of sound dampening. Even with the cutout closed, doors closed, air off, and radio off, I couldn't determine accurately if the noise faded above 2K revs, mostly due to the patriot dual's slamming the valves open and shut and the super aggressive MS4 lobes.

As far as noise while driving, 5th and 6th definitely have a whistling/chirping noise. Similar to speaker interference I referenced earlier. 4th gear was quiet while 1st definitely had a whine and possibly some knocking, hard to hear/notice over the whine and roar of the engine. 2nd had some whine and 3rd was inconclusive.

As far as the knocking sound goes, whenever clutch engagement from a stand still isn't 100% (due to either over/under revving, high load, hill, etc.), I get the chatter/knocking sound exaggerated 10 fold. This is from a clutch with around 8-10K miles on it and I expect the Monster Stave IV to have some chatter, but I think this chatter/knocking that I am hearing is the same as when I hear it in neutral at a stop, just exaggerated, not clutch chatter.

One last thing to note, the chatter and knocking also sound exaggerated when I shut the engine off, almost like an old school diesel when they are shut down.

Does any of that make sense and/or is relevant?

thesource

iTrader: (60)

The clutch isn't going to chatter while the car is sitting still but because of the aggressive camshaft and the rigid clutch disc, this could be the gear chatter you are hearing. As for the whine, thats not the clutch. If there is enough noise to hear over the exhaust going down the road, thats the input shaft and cluster gear inside the transmission. The gears could be worn just enough to make a noise but not enough to fail you anytime soon. Its tough to say without actually looking at the gears inside the unit. Personally, I would drive it like that until it breaks.

1SLwLS1

iTrader: (6)

Sounds good enough to me. It doesn't seem like failure is around the corner as WOT pulls perform like normal. I will update once I swap the fluid. Thanks for the help.

thesource

iTrader: (60)

No problem. You can try going with a little thicker fluid in the unit to cushion the gear chatter but you might experience shift related issues in cold weather until the transmission warms up.

1SLwLS1

iTrader: (6)

Saturday I went with Syncromesh as I figure it can't be any worse than the super tech junk I drained out. The high pitch squeal in 5th and 6th completely stopped. The idle chatter got marginally quieter, and the 1-3 noise went down quite a bit. I also went ahead and put in a bronze shifter cup I had laying around.

Some of the noise I think was from the center console rattling against the shifter. MGW's boot is quite thick and I have the #6 boot cut down to slide over the MGW base beneath MGW's small boot. I trimmed the center console down a bit with a Dremel trying to get as much clearance as possible, as the center would definitely shake and squeak when in reverse. I put a small shim at the front mounting point of the console to move it towards the passenger side for added clearance but I fear now my lower seat bolster is squeaking against the center console, haha. Chasing one noise after another. I may see if I have any play in the rear transmission mount and see if I can get 1/8-1/4" of movement towards the driver side so everything will fit as designed.

Again, thesource, thanks for the help.

AR15 guy

iTrader: (1)

My stock motor is doing something very similar, but not as loud as yours. Symptoms are almost exactly the same.