Engine/Transmission (1998.5 - 2002) Question - Idle Clatter

[PRout]

Clutch Question - Idle Chatter

Hello Fellow TDR members,



Long story short (I hope)



Just needed to get a clutch put in (at 90k) due to my 6sp getting really hard to shift. Ended up being a bad pilot bearing.



Went with the S. B. 0090 CON 0. My first impression is that this thing feels alot better than the stock one ever felt. It is smooth as silk, and I've just been babying it for the last hundred miles.



It shifts better than ever & so far am satisfied with it. It doesnt have that slight mushy slip the old one had. It feels alot more solid on slight roll-ons.



The only thing I wanted to find out was, is it normal to have quite a bit of Idle Chatter noise?



Mine is pretty noisy, in fact you can easily hear it over the engine noise, and thats w/ a stock straight pipe. Push in the clutch & its quiet. Slightly push in the clutch & it still does it, until you get to the release point, then it goes away.



If this is normal then thats fine. Just wanted to be pretty sure I dont have a bad bearing, or wont hurt the transmission, because it sure sounds bad. Can also feel the vibration in the shift knob.



It was installed by a reputable dealer, so it should be ok. Was just looking for a few knowlegable opinions before I call it a good install.



If it could be a bad bearing I want to get it back in the shop before something is damaged.



Thanks again!



By the way, the more I drive it, the more I like it. Its a good clutch.



I just dont remember reading about the southbend making as much noise as the dual disk ceramic type thats all.

 

[GWHaley]

clutch rattle

Obviously not being able to hear the noise firsthand, I can only guess as to what the noise is for sure. My opinion is though, is that if it is making enough noise to hear it over the engine and it only does it when the clutch is engaged, I would definetly take it back-you could have a worn input shaft end where it rides in the pilot bearing or a input shaft bearing problem. Whatever, it's not right and you should take it back.

 

[PRout]

GW, thanks for the input.



The only thing that makes me think it shouldnt be the transmission or the shaft is that it sounded normal when I took it in. It was quiet. Was just getting harder to shift all of a sudden.



So if the noise is the input shaft, then it seems to have changed during the install.

 

[GWHaley]

clutch rattle/chatter cont.

Shortshift, the point I was making about your situation is that the noise you are hearing is not normal. It could be the input shaft, pilot brg. , throwout brg. , pressure plate or clutch plate itself. When you push the pedal you put pressure on the throwout and on the fingers of the pressure plate. The clutch plate gets slightly loose as does the input shaft. Based on this, the noise could be coming from any of those parts. Back to the main point-it's not normal! (sorry to repeat myself). Hope this helps (I wish I could hear it myself!).

 

[PRout]

Understood, you're referring to clutch related parts that may be bad.



Well, you may be right that this is not normal.



I am going to take it back Monday, to either have them check it out, or get it documented in writing that I detect a new, unusual noise, and that they claim its normal (due to the bigger hub assy which is what I've been told).



I could record the sound into a wav file, but by the time I get it processed & posted, it would already be Monday .



Either way, the reason for posting the question on this thread, is so that I can return with more knowledge.



Thanks for your opinion.

 

[krs]

shortshift,

I agree with GWHaley - it's not normal to come away from a new SB install with noise as you describe. Call Peter @ SB before you call your installer. He'll give you straight answers.

 

[PRout]

Yeah, I was kinda thinking the way you guys were, but was trying to keep an open mind & think positive.



Ok, heres one more clue then I'll shut up & quit boring you guys with this ungodly subject. .



It does only seem to rattle at idle. If you gradually raise the RPM's it goes away at say 900-1000 r's.

 

[GWHaley]

Idle chatter

shortshift, you are definetly not boring us with this problem. Any problem someone has, may pertain to someone else at some time. I'll be looking forward to finding out what happens. Because the noise goes away at 900-1000 rpm doesn't mean anything exept being part of the symptom.

 

[krs]

Think of having a shaft that is a loose fit in a hole. When there's no load on the shaft it would be free to flop around loose in the hole, making noise. But when the shaft loaded from any side by centrifigal or torque loads sufficient to make it seat against one side of the hole or another it would make less noise than before. It would still be loose.

Also consider that the inherent noise of a running diesel engine makes it very difficult to hear dangerous noises at all. The fact that you hear an unusual noise is enough to let you know that something is wrong. There is nothing about the new clutch that is ever noisier than the stock one if both have the same installation features.



Really, call Peter. He'll adopt this problem like it's his own truck.

 

[PRout]

KRS,



Yes, thats possible. I just dont understand why I took it in with a totally quiet sounding clutch/transmission, and now, after having a new one installed at a reputable dealer (leaving names out), it makes this noise.



It was explained to me (by Peter's assistant) that sometimes if you have the SB GOLD setup, that you will experience this noise due to cramped space in the housing, and vibrations from the crank are transmitted to the gears while in an idle situation, and it is a normal situation. He explained that sometimes the noise goes away, and sometimes it doesnt.



That is why I asked the question here, because it sounded logical, but wanted some OTHER, KNOWLEGABLE opinions from people that either install them, or have EXPERIENCE with this clutch. I am not comfortable thinking something that makes a vibration, is an indication of wear taking place somewhere.



We all have some basic understandings of clutch components including me. I'd like to get a "second" opinion from someone that knows Southbend clutches.



Thank you.

 

[NShadbolt]

Re: Idle Chatter

Wow that sounds just like my truck. I bought mine a couple of months ago. It had this horrible noise at idle. Sounds like the gears in the transmission were just rattling around. I brought it back to the dealer and they replaced the transmission under warranty, it also had the rear seal blow out and was out of oil. When I picked up the truck it still made the same noise. Only at idle with the clutch peddle up, and when you raise the rpm's just a little it goes away. I have also heard it a little under hard acceleration at low rpm. The dealer said that it was normal and after arguing about it they had me talk to there mechanic and he said ALL six speeds do this and it is normal. I have asked around and everyone tells me it is a Pilot bearing, throwout bearing, or input shaft bearing. Considering it was a brand new transmission and it makes exactly the same noise as the old one I doubt it is the transmission. I do not know if the clutch in my truck is stock or not but I bought it at 36,000 so I assume it is. I hope we can find out the problem b/c it is not fun sitting at a traffic light and having to hold the clutch down. Good luck

 

[PRout]

NShadBolt,



I can only speak for my truck, but it never made that noise with the stock clutch. The only time it would make anything similar to that would be if you were under load in a high gear at low rpms, and if you rolled on the juice a little heavy, the gears would growl a bit to let you know they were under a strain. Always tried to refrain from doing that. Im sure youre ok after what you've gone through with the new trannys. Thx for the input.

 

[PRout]

Follow up:



Spoke with Peter.



Even though he was busy, he took the time out for me to explain the situation. He was very informative and this is why i'm glad i did business with him.



He told me that this noise does happen. He explained that it is due to the rather stiff hub assy basically transmitting the crankshaft vibrations backwards (sound familiar as in Mcleod?)



He said in MOST CASES, this noise will get quieter when the hub starts loosening up ( I assume he's referring to the dampener springs). But because he cant hear mine, he couldnt be 100% sure it wasnt my input shaft bearing, but said he did not think so.



It boiled down to, if it stays the same, or gets quieter thats good. If it starts getting louder, then its probably the input shaft bearings, and thats obvously bad.



My opinion is, since it didnt make the noise before the install, I see no reason for the input shaft bearing to instantly go bad because of a clutch install (at a reputable dealer). And, It does seem to be getting somewhat quieter, which according to the above is good, Im going to call it good, an continue to monitor!!



P. S. I do like this clutch! Im not an abuser, but this baby is smooooth, and feels solid. Makes me realize how much the stock one was slipping. transmission shifts good again too.

 

[WadePatton]

Yep. Mine was the same after SBC went in. 5 or 10 thousand miles later, you can't hear it anymore.