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I replaced the clutch in my 1993 a few years ago (I typically put less than 2k miles on the car a year) and immediately after I noticed a slight amount of noise at idle that goes away when the pedal is fully depressed (Exedy OE HD clutch kit). I was told it was normal clutch chatter and I left it at that. However, after flogging on the car pretty hard for three days at Tail of the Dragon in October, the sound is now MUCH louder. It sounds like a mechanical clacking noise that still goes away when the clutch is fully depressed. It also gets louder with RPM. The car still drives and shifts fine. The only change is the noise. I drained the trans fluid and it has a good deal of glitter in it, so I pulled the trans thinking my input shaft bearing had failed. I got a low mileage used 95 trans that I am getting ready to put back in the car, but it seems to have even more input shaft play than my 93 trans.
In summary, is there a way to check the input shaft bearing condition without disassembling the trans? Is there something else that I should be looking for that could be making the clacking sound if my trans isn't the culprit? I already plan on checking the flywheel nut torque once I remove the clutch (I machined the flywheel last time it was apart). Any help is much appreciated.
Also....Noise/rattle sounds like a clutch, throw out bearing or a bad surface flywheel. Most folks have bad luck with machining the flywheel. 9 out of 10 times you will ruin one getting it machined.
Also....Noise/rattle sounds like a clutch, throw out bearing or a bad surface flywheel. Most folks have bad luck with machining the flywheel. 9 out of 10 times you will ruin one getting it machined.
The bad input shaft bearing I had was a growling noise. IIRC it was most noticeably sitting at idle in neutral (clutch engaged). Nothing like the “clacking” you’ve described.
That does make me feel better, thanks! Now I'm worried that it may be my flywheel. I machined it myself (I am a journeyman toolmaker) and I know that the step is dead-on within specification, and I used an abrasive disc on the friction surface after machining to make sure there was a uniform surface for the disc to break in on. I'll get the clutch off of the flywheel and give everything a thorough inspection before I throw the trans in the car.
Last edited by redheddude222; Nov 30, 2023 at 03:18 PM.
I replaced the clutch in my 1993 a few years ago (I typically put less than 2k miles on the car a year) and immediately after I noticed a slight amount of noise at idle that goes away when the pedal is fully depressed (Exedy OE HD clutch kit). I was told it was normal clutch chatter and I left it at that. However, after flogging on the car pretty hard for three days at Tail of the Dragon in October, the sound is now MUCH louder. It sounds like a mechanical clacking noise that still goes away when the clutch is fully depressed. It also gets louder with RPM. The car still drives and shifts fine. The only change is the noise. I drained the trans fluid and it has a good deal of glitter in it, so I pulled the trans thinking my input shaft bearing had failed. I got a low mileage used 95 trans that I am getting ready to put back in the car, but it seems to have even more input shaft play than my 93 trans.
In summary, is there a way to check the input shaft bearing condition without disassembling the trans? Is there something else that I should be looking for that could be making the clacking sound if my trans isn't the culprit? I already plan on checking the flywheel nut torque once I remove the clutch (I machined the flywheel last time it was apart). Any help is much appreciated.
With regard to the clutch surface causing chatter, I have a question:
Does it occur with the clutch totally engaged, i.e., idling or under power with foot off the pedal? If it does then it's not a surface irregularity or finish issue. If it only occurs at partial engagement , i.e., clutch still slipping, then it's likely related to clutch surface irregularity or uneven finish.
With regard to the clutch surface causing chatter, I have a question:
Does it occur with the clutch totally engaged, i.e., idling or under power with foot off the pedal? If it does then it's not a surface irregularity or finish issue. If it only occurs at partial engagement , i.e., clutch still slipping, then it's likely related to clutch surface irregularity or uneven finish.
The noise happens any time the input shaft is spinning, and only stops when the clutch pedal is touching the floor. I can hear it "spin down" to a stop as soon as the clutch is disengaged.
The noise happens any time the input shaft is spinning, and only stops when the clutch pedal is touching the floor. I can hear it "spin down" to a stop as soon as the clutch is disengaged.
Doesn't sound like a FW balance or surface issue. Also doesn't sound like a TOB issue. Like you said, something inside the trans.
I'm going to double check flywheel nut torque and inspect the flywheel the best I can. If anything looks suspicious I'll order a new flywheel just to be safe. ACT has a hell of a deal on their Streetlite Kit (600145-02) right now. Has anyone had any negative experiences using this on a mostly stock car with sequential twins?
I'm going to double check flywheel nut torque and inspect the flywheel the best I can. If anything looks suspicious I'll order a new flywheel just to be safe. ACT has a hell of a deal on their Streetlite Kit (600145-02) right now. Has anyone had any negative experiences using this on a mostly stock car with sequential twins?
Good plan....let us know your results. I think the ACT is popular but have no first-hand knowledge.
I took the clutch off and everything looked great. Flywheel nut torque checked out ok. I couldn’t find anything wrong, so I added some grease to the pilot bearing and torqued the pressure plate back on. Then I pulled the alignment tool out and saw this. I believe I’ve found the source of the noise: input shaft flopping around because the pilot bearing exploded.
I took the clutch off and everything looked great. Flywheel nut torque checked out ok. I couldn’t find anything wrong, so I added some grease to the pilot bearing and torqued the pressure plate back on. Then I pulled the alignment tool out and saw this. I believe I’ve found the source of the noise: input shaft flopping around because the pilot bearing exploded.
That'd do it. Lot better than having a trans issue.
