Clutch Questions

[MBlanks]

Well, I finally got around to replacing my throwout bearing on my truck that has been making an awful racket for the past month or two. As expected, the throwout bearing was falling apart and I am quite surprised it was still intact. While I had the transmission off, I went ahead and installed a South Bend Clutch MU 0090 O clutch. Everything went well, except now when I put the truck in neutral and let off the clutch a moderately loud rattle begins. The rattle does not occur when in gear or when the clutch is actuated. This leads me to believe that the new throwout bearing is making some noise when it is not under load. Perhaps where the bearing is seating on the actuating fork it is jiggling. However, since I cannot really locate the noise, I was wondering if anyone had any clues. I am aware that the clutch is going to need to break in, but this doesn't sound like something that is going to go away. Do y'all have any clue what it might be? If you need any more information let me know. Thanks.



Mark

 

[BushWakr - RIP]

I'd strongly recommend calling Peter at SBC for some of his input/advice. .



Pastor Bob...

 

[sparks57]

I have heard complaints about this before, I also suggest calling Peter.



This is the one reason why I am hesitant about going SBC, because he may provide great customer service, but the fact that he has to provide it so much... . ???

 

[Bob Beauchaine]

It sounds as if you used an off the shelf throw-out bearing - correct me if I am wrong. I went with Peters CON-O and his throw-out bearing right after I installed my NV4500HD and it is still quiet plus the clutch keeps getting better and better. Just my . 02 worth. By all means call Peter.



Bob

 

[Philip]

I put the truck in neutral and let off the clutch a moderately loud rattle begins. The rattle does not occur when in gear

Sounds like the slave cylinder is not retracking all the way. The throwout bearing is touching the pressure plate fingers.



(I am not sure if they use a retrack spring on the slave cylinder or not. I haven't played with a stick shift setup on these trucks much).



If it does have a retrack spring. Replace it. It might be weak.

 

[BCook1]

Mine is louder too.

I installed a Con-o clutch in mine and I too notice that the clutch noise is louder than the old one. It only occurs in neutral with the clutch pedal out. As soon as I step on the clutch it stops. A similar noise, but quieter, is comming through my throttle pedal. As soon as I step on it, the noise stops. But not the clutch noise - it is different. If I put moderate pressure on the throttle and push in the clutch, the truck is noticably quieter. I just ignore them. 10,000 miles later the Southbend clutch is still a dramatic improvement and one of the best mods I have made to the truck.

 

[MBlanks]

Well, I talked to Peter at SBC, and he said that the "neutral clatter" is quite common in these trucks. He says that it is because the clutch disk hub is machined to a much tighter tolerance than stock and this makes it so that it transmits the sound of the diesel noise through the input shaft. If the hub is looser, then there is a little wiggle room for the vibration to not be absorbed by the input shaft and this would explain why when it is under load there is no noise. Does this make sense to y'all?



Also, while I had the transmission out, I changed the fluid and put in Mobil 1 Super Syn 5W30. And since reinstallation there is a significant growl when I first shift into 3rd gear at relatively low RPM's. My buddy who owns a '93 W250 says that it sounds like his 3rd gear did before it went out on him and he had to replace the whole transmission. What I don't understand is how it could be doing this just after installing a clutch and changing the fluid. The transmission only has about 70k miles on it, because it was replaced under warranty with an updated model. Any clues what THIS noise could be???? (this is slightly frustrating)



Mark