V1 F35 input shaft noise

[Stretch2126]

Looks like the trans will start making noises in neutral. Goes away when the clutch pedal is pressed. It still drives great but the noise seems like it’s becoming more consistent. Anybody else have this happen?

 

[snirtman]

Looks like the trans will start making noises in neutral. Goes away when the clutch pedal is pressed. It still drives great but the noise seems like it’s becoming more consistent. Anybody else have this happen?

I was going to guess throwout bearing, but they're typically noisy with the clutch pressed in, quiet when released. I see from your build log that you recently replaced your clutch/flywheel - any chance one or more of the pressure plate bolts is loosening? Any excessive vibration in neutral while revving engine?

 

[Desert Sasqwatch]

Seems there is lots of discussion about the F35 making rattling noises in neutral.

I know this is also true for the F40 as well.

 

[Stretch2126]

I suppose it could be the clutch but DS’s video is almost exactly like mine it seems like. I can clutch in and out sometimes and it’ll go away but it comes back. I would hope the clutch isn’t already backing off after only having it on for a couple months. I’m putting some fresher oil in the case to see if it does anything. Not metal in the gear oil.

 

[snirtman]

I suppose it could be the clutch but DS’s video is almost exactly like mine it seems like. I can clutch in and out sometimes and it’ll go away but it comes back. I would hope the clutch isn’t already backing off after only having it on for a couple months. I’m putting some fresher oil in the case to see if it does anything. Not metal in the gear oil.

FWIW - The guy who posted the video replied to some comments that it was the "Incorrect preload on final drive bearings"

 

[Stretch2126]

FWIW - The guy who posted the video replied to some comments that it was the "Incorrect preload on final drive bearings"

Yeah I saw a couple other videos saying input shafts giving out or another internal matter. It might be time for an f23.

 

[snirtman]

Yeah I saw a couple other videos saying input shafts giving out or another internal matter. It might be time for an f23.

I'm certainly no transmission expert, but I've read that the GM transmissions are usually numerically designated in newton metres, so the F35 is rated at 350 Nm, the F23, at 230 Nm, F40 at 400 Nm and so on. Seems like the F23 would be a step backward if you're overpowering your F35?

 

[Ross]

The F23 is a step backwards according to GM, but the people who push these engines hard swear by the F23.
They say it shifts better, is cheaper, and is much easier to find in the auto recycler yards too.
Justing Reed runs 600+ hp thru his F23, so that seems pretty solid.
Also, the goblin weighs half the Cobalt, so that cuts the load down on the transmission.

 

[Desert Sasqwatch]

This whole post thread has lots of good information about the F23, installing a LSD, and real world experience with it in some higher HP builds.

[GUIDE] F35 to F23 (with LSD) Transmission Swap

I'm at a good point where I believe this can be documented. I'm still trying to figure out how to get the Speedometer to work, so if any you guys have thoughts around this please share! FIXED! First, why would someone do this? Well, first is performance. Going from the F35 with Final Drive of...

dfkitcar.com

 

[finazzoty]

Sorry to bring up an old post, but I'm wondering if anyone ever figured out a resolution to this? Funny thing here about it potentially being "incorrect preload on final drive bearings" is that I have a brand new 0 mile F35 and I am also experiencing this issue. Would love to know if anyone ever figured this out, or maybe its not something to worry about. I will say though....it does sound like its something to worry about. Metal on metal noise is never good

 

[Desert Sasqwatch]

Are you sure it not just clutch noises? Does the noise change if the clutch is engaged or disengaged? Some performance clutches make noises, the F40 clutch makes noises no matter what - performance or stock.

 

[comegetjoe]

Are you sure it not just clutch noises? Does the noise change if the clutch is engaged or disengaged? Some performance clutches make noises, the F40 clutch makes noises no matter what - performance or stock.

Well thats good to know

 

[finazzoty]

Are you sure it not just clutch noises? Does the noise change if the clutch is engaged or disengaged? Some performance clutches make noises, the F40 clutch makes noises no matter what - performance or stock.

Agree @comegetjoe this is good to know, as I was not aware this was the case. @Desert Sasqwatch It’s a Clutch Masters FX500. I suppose this could be it…never actually thought about the clutch. My question though is: if this is indeed the case, what is hitting what??

 

[Stretch2126]

I have an FX400 and an aluminum flywheel so it’s chattery when not under a lot of load. But in neutral I do hear the bearing. It changes if I hit the clutch a couple times.
If you hear noise when you Coast or have very little power being pushed through it the gears will make noise. Especially if you have a light flywheel

 

[finazzoty]

I have an FX400 and an aluminum flywheel so it’s chattery when not under a lot of load. But in neutral I do hear the bearing. It changes if I hit the clutch a couple times.
If you hear noise when you Coast or have very little power being pushed through it the gears will make noise. Especially if you have a light flywheel

This is potentially music to my ears. I also have a ZZP aluminum flywheel. Would you mind taking a listen to the videos here to see if your diagnosis applies?

Rough Idle Issue - Google Drive

drive.google.com

Videos 6290 and 6316 have the best audio of the noise in question.

 

[Stretch2126]

This is potentially music to my ears. I also have a ZZP aluminum flywheel. Would you mind taking a listen to the videos here to see if your diagnosis applies?

Rough Idle Issue - Google Drive

drive.google.com

Videos 6290 and 6316 have the best audio of the noise in question.

That is a lot louder than mine. I don’t know if the idle makes it worse, but that sounds like somewhere in the housing might be loose. If you didn’t have trans problems before you probably don’t have them after a swap. Does the sound go away when you hit the clutch? That’ll tell you give you a little more info.

 

[finazzoty]

Well the 6316 video makes it sound alot louder than it actually is in person (surprisingly). Its actually hard to hear the sound from the driver's seat, so I'm not sure if it goes away when the clutch is pushed in, but I THINK it does. I can tell you for sure that when you rev the engine, the noise goes away completely, and then comes back as the engine returns to idle. As soon as I get back to Atlanta on Thursday, I will have someone sit in the seat and push the clutch to see if it goes away.