Hey all,

Recently got a strange rattling in my 2g when at an auto x event. Sounded like a bearing, I had determined it was the tranny side. The rattle is bad on decel and goes away when you push on the clutch pedal, even just touching the cutch pedal a little makes it go away. I had thought it might have been a faulty TOB as I had that and clutch setup replaced maybe 6000kms ago. Ordered a new TOB and tossed it in, got it back together and same thing. Now I've been leaning towards the springs in the clutch disc, running an ACT sprung street disk. I've ordered a new disk so hoping to bang that in when it gets here. I never really thought to look into this as I thought for sure it was the TOB. Has any had a similar experience? Or think it could be something else? last thing I want is to haul it all again and toss it back together and not fix it

Any info/thoughts would be great

Cheers,
Jim

If you've got the tranny out anyways, pull it apart and take a look, all you have to do is pop off the two nuts and a roll pin to be able to inspect everything.

Definitely worthwhile, especially with a such a new clutch setup (therefore less likely to be the cause, imo).

If you rest your foot on the clutch does the noise go away?

Does the noise increase with vehicle speed?

Does the noise increase with engine RPM?

When coasting in neutral, is the noise present?

Does the noise happen when you are reversing?

I got something similar. Happens at idle for me. The lower the idle, the more noticeable it is. sometimes when I push the clutch in it stops, but not always.

My flywheel is really chattery Stephan and presents the same thing you are talking about. What flywheel you have?

I got a Fidanza lightweight one. Also got a 6 puck unsprung ACT with a 2900 ACT pressure plate.

clutch in it goes away and slight touching the pedal is gets quiet as well

Seems to increase a little when I rev in neutral

coasting in neutral it's still there, seems to always be there when clutch pedal is out, it's bad on decel in gear

I can't confirm reverse. I have the tranny out again now, my clutch disk looks worn but all the springs in the center look to be intact.

I think I'm going to pop the end cap off too and have a look.

I've been getting a lot it could be input shaft bearing as well, it's a shep built tranny I bought used with low miles, but that doesn't mean it's not an internal bearing.

What flywheel do you have?

Stephan we have the same flywheel and from what I understand they can be pretty noisy, especially when cold.

Ah. Phewf! I was worried for a bit. I'd just end up turning the volume up on the stereo when I heard that noise. If I can't hear it, it's not there xD. Unfortunately that's not a good idea. Lol

Hahaha, true!

I have an ACT Xact chrome moly flywheel. This flywheel has been in the car for years, previous owner had it as well, noise was never an issue before now.

Could it be your throw out bearing?

A difference in the sound when you push the clutch in makes that a possibility.

I've just replaced the TOB with an OEM one as I had an ACT in there and it didn't change a thing.

I hope it ain't, but think it could be a loose bolt? Or does it not sound like that?

Its sounds like a your flywheel is too light! my buddies G5 with a lightened flywheel sounds like the tranny is a rock tumbler. this is common when you go TOO light.

Huh. I'll look for a slightly heavier one next time then. Is it bad for the engine for it to be too light then? Or is the sound not dangerous?

Its just a bad sound, if you can handle the drive-ability of a super light flywheel then you will be fine. if the sound is in fact the super light flywheel you have (and I believe it is) there is no need to worry, although the sound is damn annoying.

Driving with it is not bad. I've gotten used to it, and I won't drive unless its nessisary.

What are guys talking about a flywheel for? Clearly the trans/diff is making this noise under a load

And I have a fidanza fw. it makes NO noises.

Bryan correct me if I'm wrong........but I believe his fidanza flywheel makes noise...especially when its idling while cold. But Eng could be right, it is totally possible that something else inside the trans could be astray.

And correction...the flywheel itself doesn't make the noise, its super lightened weight causes noise in the trans rotating assembly....if it is the flywheel causing the noise...is it really damaging anything or making unnecessary chatter?

Didnt this noise just appear and uve been running the same flywheel with no noise? Id rule that one out........

Yeah, that's what I had mentioned above. Stephan and I seem to have the same thing.
As for Jim, that can be ruled out.

You guys get carried away some times

Poor Jim is gonna have to pull it apart (what Salomon said) and inspect it.

BUT, not all is lost.

This is a good time to get other sh!t done while the tranny is out. (ie. POR15 some of the engine bay, wire tucks, whatever..)

I doubt it's the trans. I only get the noise at idle. It must be somewhere in the flywheel/clutch assembly.

If he's gonna have the trans out anyways, it's no more than 15-20 minutes of work to get it mostly pulled apart. Worth the effort for the peace of mind.

I have the trans already out again. I'm going to replace the clutch disk as well and open up the trans for a peace of mind look. Hopefully something obvious so I can put this to rest and get racing

Replace your TOB, even though you already have, replace it anyway.

Parts do come bad out of the box.

i had the same thing that you explained in my evo.

and what i found out was it was the springs in the clutch getting loose and rattleing around ..

i replaced my clutch and sound went away.

My clutch doesnt have any springs and it rattles, for the record.

Every rattle is different though.

Input shaft bearing if the new disk doesn't solve it.

thanks guys, The new disk should be here today. But while it's out I'm going to open it up for a look, I'd like to check it all out now instead of installing it once again with just a new disk and TB then come to find it's something else

I got to spend a little time at it tonight. Took the end cap off for a look, nothing seemed off so I decided to keep going to be thorough. Got it all apart, and the bearing doesn't seem to look bad at all. It didn't fall apart like most people say when theirs was gone. Other than visible I don't really know how else to say it's gone, but seeing how I have it all apart now I think I will replace the bearing anyway. Anyone know the best place to grab one? Ziggy sell them? I don't have the part number

here are some pics for reference



I got my new clutch disk now as well.

Any thoughts? I guess with replacing the bearing and new clutch disk, one would HOPE this will be the fix. I miss racing..

Input shaft bearings in my experiance make noise when loaded at low speeds. Usually sound like a wheel bearing but in the tranny. That bearing looks decent no pitts or chunks missing.

The bearing to me looks good. my noise was idle and moving, basically anytime the clutch pedal was out, was bad on decel as well.

How do the rest of the tranny bearings look? Anything unusual?

Its hard to tell from the pic, but the small end of that bearing shell looks discoloured. Does it look like it was touching inside the tranny case?

Reza, I'll snap more detailed pics tonight. I had a look as I was taking things apart and nothing seemed to jump out, all seemed clean and no unusual markings or metal shavings or anything, granted I was more determined to get a look at the input shaft bearing, but I'll scan them all tonight.

Ok it might just be the angle that pic was taken, the small end of the bearing looks like it was touching the inside of the bellhousing, but I could be wrong. Since your in there just double check all the bearings before putting it back together.

Got to have a better look tonight, again the input shaft bearing looks perfect, and all other bearings seem to be ok as well. The one thing I did notice was the shim for the bearing on the output shaft below the case and center diff, see pics below. It looks as if the shim is scoured a bit, tried to snap some pics, the case doesn't look bad on the other side but I don't think the shim should be like this :S






Looks like I'll need to re shim, I guess the bearing spun or something? Thoughts?

Thanks,
Jim

Good day Jim

I'm chiming late into this post and have only "skimmed" through this tread.

The problem you are describing is sometime associated with TOB or Input Shaft bearings. Other components can create similar noise.

Having said that you have observed all of those components and notice a scored Shim. It has been two years since I open a Tranny and do not remember exactly how that Shaft is driven.

Factory Input Shaft and Center Diff specs call for an "Enplay" while the Intermediate, Center and Output Shafts require a Preload.

You can find in here an older post where tighter specs are suggested; IIRC those specs were suggested by Tim Zimmerman from ECMLink Board.

I would suggest that you verify those tolerance and use 0.004" to 0.007" of Preload for your Input Shaft. 0.005" to 0.007" Preload for the Intermediate, Center and Output Shafts and 0.002 to 0.0067" Endplay for the Front Diff.

Hope this helps.

Ghislain

Just reread your original post.

You mention that the noise happen while on deceleration. Under deceleration the Wheels drive the Tranny so the Output Shaft is under "negative torque". A small backlash can cause this type of problem under this condition. My bet is that this worn Shim is part of your problem. Inspect the Output Shaft and Front Diff Teeth and their wear patern and if not worn reshim.

I think that Paul Sitarski had an Output Shaft for sale.

As for the Shim; they can be hard to procure. I had some water cut out of a 0.062" hard metal (60 on Rockwell scale) and rectified to the thickness I needed.

I'm confident that "should" fix your problem.

Ghislain

My trans rattled on decel so I got it opened up. It was mint inside except for one bearing and one shim, which was assembled incorrectly probably at some time when it was rebuilt. I don't recall if it was the wrong shim thickness and/or the wrong placement but what you're describing is familiar.

The shim looks normal, you'll need to measure it to see if its bad or not. It's hard to say what the issue is. If I had the trans in front of me, I'd figure it out in no time. It's hard to diagnose a tranny problem with just a few pics. If all the gears and shafts are fine, it can only be a bearing.

thanks guys! for peace of mind I've decided to order new intermediate shaft and input shaft bearings and replace them while it's open. I've been told either could fail and seeing how I want this fixed I'm just going to do it, then check the tolerances and preload everything except the diff. New flywheel bolts and new clutch disk, hopefully it will be fixed. Will update once I get it back together,

Jim

So the plot thickens, few bearings are now replaced in the transmission, just waiting on getting some shims to get the preloads I wanted.

Last night I decide to take off the flywheel as I wanted to replace the bolts and resurface it for the new clutch disk. here's what I found, I've never seen anything like this before. Good thing I looked. It was an ACT flywheel. I'm guessing a bolt loosened causing this? They were torqued and Loctite when installed with the new engine, but some seem to come easier than others. Either way I'll be ordering a new flywheel now. Crank looks fine, just need to give it a quick brush, looks like some of the material transferred. Bolt holes look fine in the crank.

my guess this definitely was a factor in the noise as well. By the time it's all said and done, I'll have a new flywheel, bolts, clutch, TOB, and tranny bearings with preloads I want. Hopefully she'll be good to go then

Looks like you found the problem. Use some new OEM flywheel bolts, torque to spec and red loctite.

The bolts may not have backed out, they could have been too long or possibly some foreign object got in between the crank and the flywheel when it was bolted up and later crumbled and fell out, leaving it loose.

The flywheel bolts for auto trans. are shorter and there is a spacer ring of sorts in the crank for autos. Unlikely, but be aware in case any parts from an auto were used.

Only thing is now, I have new parts on the way, but this is what my crank looks like as a result

Wow... that is fucked. It's hard to be certain from the pictures, but it appears that there is a decent amount of material missing.

I would be worried about running that rotating assembly without a balancing (though my engine building experience is limited).

Was there a spacer in there at some point?? That looks like it needs to be cleaned up before anything is bolted up there again...... The crank and the flywheel.

No spacer, flywheel was bolted to crank. I don't think this will clean up, there are some pc's of metal that are not flat and one spot has some missing. I'd say the crank is F'd and going to need to be replaced. ugh one thing after another. All that started as a noise and a car running now I'm into quite a few repairs. DSM FTW...

Anyone have a 7 bolt crank in good shape to sell?

I'd clean it up with some sand paper and a grinder.

Just kidding, you definately need a new crank! By looking at the threads, it almost looks like you didn't use red loctite. I also never reuse flywheel bolts.

yea at this point I had cleaned it all up, used some wire brush on the crank end chased the threads to see what I was up against so they look pretty mint, too bad the crank can't say the same :S

Would you not want to install new bearings if you're replacing the crank anyway?

Ziggy can probably help you there.

I'd replace all the bearing affected if I was doing the crank. I need a new crank is the key. Just so happens I have a 2.4L sitting in my garage that's for my colt project, looks like that will be going in the talon for now.

maybe an excuse to build my bottom end now lol