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SpeedingFirebird
06-03-2009, 09:25 PM
Tonight was the first time I took my car out after racing. I noticed a loud whine that sounds like it is coming back the back of the car. It occurs only when accelerating with the tranny engaged.

1. clutch in - no sound
2. clutch in, revving enging - no sound
3. clutch out, no gas - no sound
4. clutch out, throttle - whine.

Any rpm range from that I could, and almost any amount of throttle.

T5, aluminum driveshaft, 3.73 motives with Auburn posi.

I have some thoughts, but I want to see what you guys think.

The shift knob (flameball) picked up a rattle too. It is as tight as it can go...WTH?

freakv6
06-03-2009, 09:51 PM
The rear most likely is gonna be the gears. I want to say that motive is known to end up with noise aren't they? on number 3, even though you are giving it no throttle is the car still moving, or do you mean clutch out and out of gear as well? Are you sure its coming from the back of the car and not the tranny itself (throwout bearing)?

As for the shifter ball i would imagine the threads are not actually cut into the ball are they? I would guess their is a metal insert that has the threads, that insert is prolly a bit loose and causing that rattle.

Pace
06-03-2009, 10:50 PM
Start out with a few cheaper things first. Look at the tail shaft seal on the trans and make sure it's not cracked. Mine cracked just from installing an aluminum driveshaft. Maybe look at the u-joints on the driveshaft. Also check the trans mount to see if it's still solid and not broken or loose.

Gears are really what come to mind, but checking the small things first shouldn't hurt. The rear end on my car has been howling under load in the past few times I've have it out since September.

From what I recall, Richmond gears tend to be the ones that are noisier, but setup and condition are really what it comes down to.

SpeedingFirebird
06-04-2009, 07:30 AM
The rear most likely is gonna be the gears. I want to say that motive is known to end up with noise aren't they? on number 3, even though you are giving it no throttle is the car still moving, or do you mean clutch out and out of gear as well?


All of them are with the car moving. I think that rules out the rear end since with the engine disengaged, it goes away.



Are you sure its coming from the back of the car and not the tranny itself (throwout bearing)?


I sounds like the back of the car, but the throwout bearing is my current thought. Note, the tranny was rebuilt a few years ago (4 - 5K miles).



As for the shifter ball i would imagine the threads are not actually cut into the ball are they? I would guess their is a metal insert that has the threads, that insert is prolly a bit loose and causing that rattle.

good point. It is sort of annoying.


Start out with a few cheaper things first. Look at the tail shaft seal on the trans and make sure it's not cracked. Mine cracked just from installing an aluminum driveshaft. Maybe look at the u-joints on the driveshaft. Also check the trans mount to see if it's still solid and not broken or loose.



Good ideas! I was curious about the u-joints. I have heard of them making noise, but never had the pleasure. What do I look for? Would it still make noise when not giving it throttle?

freakv6
06-04-2009, 08:58 AM
Oh ok, i was thinking the car wasn't moving in all but the last scenario. In that case it is most likely in the tranny. When u-joints go out it is usually an intermittent clunking sound, so if its constant i would lean towards the throwout bearing.

SpeedingFirebird
06-04-2009, 12:04 PM
Oh ok, i was thinking the car wasn't moving in all but the last scenario. In that case it is most likely in the tranny. When u-joints go out it is usually an intermittent clunking sound, so if its constant i would lean towards the throwout bearing.

I was afraid you were going to say that. u-joints are easier. The throwout is not that old though.

tmon930
06-04-2009, 02:19 PM
thats it. you're fucked.

freakv6
06-04-2009, 02:26 PM
I was afraid you were going to say that. u-joints are easier. The throwout is not that old though.

I imagine it saw a good bit of abuse at the track though. I wonder if they make a better aftermarket one. might be work looking into. Good news is that its not going to effect the driveability anytime soon. Its more just the annoyance of the sound.

SpeedingFirebird
06-04-2009, 02:36 PM
I imagine it saw a good bit of abuse at the track though. I wonder if they make a better aftermarket one. might be work looking into. Good news is that its not going to effect the driveability anytime soon. Its more just the annoyance of the sound.

I just did a bunch of research online. It looks like it is the input shaft bearing, not the TOB. This dude sums it up well:


"Noise when the clutch is ENGAGED (IE pedal off the floor).

It is the Input shaft bearing. Think about it. The throw out bearing is ONLY engaged when the clutch pedal is pushed down ( clutch = disengaged). The throwout bearing sits on the clutch fork, therefore is only active when the clutch is disengaged.

The Input shaft bearing spins, whenever the input shaft is moving, it is the first bearing to be spun if youd like to look at it that way.

There is a lot of confusion, TOB noise would be when the clutch pedal is pushed to the floor, input shaft is when the clutch pedal is off the floor."

:banghead::banghead::banghead:

$2K for a rebuild down the crapper.

freakv6
06-04-2009, 03:00 PM
Is it going to need a full rebuild for that? Surely not, even though i guess while your in there u might as well get it all done. What sucks is thats only like a 16 dollar part too. If you do get it redone i would talk with the mechanic and see if he can find you a higher quality piece then last time.

SpeedingFirebird
06-04-2009, 03:37 PM
Is it going to need a full rebuild for that? Surely not, even though i guess while your in there u might as well get it all done. What sucks is thats only like a 16 dollar part too. If you do get it redone i would talk with the mechanic and see if he can find you a higher quality piece then last time.

It may not need a rebuild. I was reading the manual, and I might be able to change it pretty easily once the tranny is out of the car. yeah...getting a lot of work done today.

firebirdkid96
06-05-2009, 09:21 AM
That doesn't sound accurate. The throwout bearing is constanly spinning as long as the clutch is, not only when the pedal is depressed. When the pedal is depressed, the slave cylinder forces the throwout bearing forward into the clutch fingers with even MORE pressure. The spring on the slave cylinder provides the TOB with a constant pressure on the clutch fingers. I'd be hard pressed to say that your input shaft bearing went out, especially with the rebuild being THAT recent, even with racing. They shim the trans on the bearing, so it's usually the tightest fitting, and a T5 rebuild kit comes with a new input bearing and bearing race...plus it retains constant lubrication from the trans fluid, whereas the TOB only gets lubricated once, or when we chose to do it/replace it.

Even if it was in fact the input shaft bearing, to replace it you just have to remove the trans bellhousing, and remove the 4 bolts on the front of the transmission for the Front retainer to come off. The bearing, bearing race, and shims are right in there. Pull em out, replace em, and reshim to get as little play as possible without binding. I believe tolerances are .000" to .004". With racing it, I wouldn't settle until I was at .001".

SpeedingFirebird
06-05-2009, 10:33 AM
That doesn't sound accurate. The throwout bearing is constanly spinning as long as the clutch is, not only when the pedal is depressed. When the pedal is depressed, the slave cylinder forces the throwout bearing forward into the clutch fingers with even MORE pressure. The spring on the slave cylinder provides the TOB with a constant pressure on the clutch fingers. I'd be hard pressed to say that your input shaft bearing went out, especially with the rebuild being THAT recent, even with racing. They shim the trans on the bearing, so it's usually the tightest fitting, and a T5 rebuild kit comes with a new input bearing and bearing race...plus it retains constant lubrication from the trans fluid, whereas the TOB only gets lubricated once, or when we chose to do it/replace it.


By your argument though, if it was the TOB it would still whine when the clutch was depressed?

The main reason I think its the input shaft bearing is that many people describe the exact same symptoms being associated with it.

Given the recent rebuild, I was amazed to have a tranny whine. I was never happy with the rebuild of the tranny; however, this it a whole new level of imcompetence.





Even if it was in fact the input shaft bearing, to replace it you just have to remove the trans bellhousing, and remove the 4 bolts on the front of the transmission for the Front retainer to come off. The bearing, bearing race, and shims are right in there. Pull em out, replace em, and reshim to get as little play as possible without binding. I believe tolerances are .000" to .004". With racing it, I wouldn't settle until I was at .001".

Right, I think the hardest part of the job is dropping the tranny.

firebirdkid96
06-05-2009, 12:43 PM
Even with the clutch depressed the TOB still spins, but because you are applying heavy pressure to the TOB, it is compacted slightly which would lead me to believe that the whine was eliminated. The trick is going to be however, does it have a slight whine while sitting still with the car out of gear and the clutch out? If the answer is no...then I don't think it's either bearing because when the clutch is out, both are constantly spinning.