How can I prevent this TOB noise...
 

... from happening next weekend when I swap in a new trans and clutch?




For about five years, about the time I was weened off my mother's teet, my TOB has always made this noise at idle. I'm tired of it, it's been there with three different clutches and three different TOBs. I assume it's the noise of it spinning with the PP, but maybe too much play between them. I've tried adjusting the engagement rod to get the slave to apply more pressure to the fork but it's never seemed to cure it. Should I just make sure everything that needs molybdenum grease has got a could coating? (fork, input shaft, bearing tabs)

need idears here people!

Get a louder exhaust!

Hydraulic clutches leave just a little pressure on the fork, allowing the bearing to touch the clutch, when it spins, it is also slipping on the clutch fingers, and that's the noise. You could put a spring on the fork that would just slightly pull the bearing off the clutch, but pull it too far back and disengagement will feel sloppy.

Maybe some more teet would stop the whining too?

Yeah, I know the TOB is always spinning, but wtf am I doing so wrong where my shit always sounds like this? Maybe when I swap in the new trans it'll help make this noise go away by having tighter forkage?

No speakers at school...is it a clicking noise or knocking and then when you push in the clutch it goes away? Cause if it is I have the exact same noise.

its a constant noisy chattering/rotating bearing noise.

Needs more grease, and good grease.

but where exactly? the diagrams in the service manual leave little to be desired.

it looks like the clutch fork "fingers" where the bearing rests on it, the spring on the fork, the input shaft, and then some other weird place I cannot determine.


http://www.boostedmiata.com/gallery2...ase_points.jpg

I think I had that noise, too. I thought it was the input shaft of the trans, noise went away when I put the clutch in.

I've had it for years...but I've had it with it. ;)

Same here! I'm really interested to see what people have to say about this because i'm sick of that sound too. I have everything apart right now and have the ability to try a suggestion if anyone has it. Engine is going back in this weekend.

I've only really put grease on the input shaft, but a generous coating where the bearing and fork meet as well as the splines of the input shaft make sense. it really could just be the bearing rattling around.

In this case the light spring to preload the tob might be a decent idea. Although, given my recent thrust bearing failure, I'm more inclined to listen to the rattle.

My 90 never did this, just did a clutch in the 92 a few months back and the trans did it before...still doing it after. New bearings and good grease. le sigh.

I used super high temp grease on mine..

I had that noise for about a week the first time I changed my clutch, I just changed it again yesterday.

We'll see if it comes back when I take the car out again

the 99-00 manual makes it a little more clear:

http://www.boostedmiata.com/gallery2...se_points1.jpg

I think the 4th image I couldn't determine is the inside grooves of the TOB where it slides onto the fork.

I have that same noise on my 1990. I was dreading taking it in. So is this more of a nuisance, or is something wrong?

When you replaced your clutch, what else did you replace with it? Throw out bearing, pressure plate, pilot bearing, etc?

all of the above. I'll be replacing all of the above + flywheel on June 5th. I would like zero noise to remain.

Brainy does not want any stupid noises. it's loud and annoying.

Also, how do you know the noise isn't coming from the transmission? Input shaft bearing, or other bearings in the tranny? Seems to happen when the transmission input shaft is spinning.

oh it's possible it's the trans, it's bad and it's getting swapped as well. but it seems as soon as there's the slightest pressue on the fork, the noise goes away, which makes me think it's the TOB rattling within the forkz.

Did you grease the portion of the shaft that went into the pilot bearing? Kinda have to be careful though, too much grease could actually press it out.

Ah. From your video it seemed like it went away once the clutch was all the way in. If it goes away when you partially press the pedal, then your theory makes sense.

yeah, if i give it just a just enough to move the fork, the noise subsides.

Mine started once i put the HD clutch in...and im pretty sure your right Brian it is the TOB.

Mine made EXACTLY that same sound, until I blew it up 15,000 miles later. I removed/replaced the clutch multiple times and am convinced it was the transmission. It started after I either put in my ACT XT, or swapped the differential, can't remember.

I have also ALWAYS had this noise with every car I own, some worse than others. Thankfully my Miata is fairly quiet compared to most of them. I always install correctly, using new parts, after cleaning all surfaces and applying grease, and yet I always end up with some kind of un-factory sounding TOB roar.

This isn't craigslist. Try not to post your personal ads here

Ive always just used a ton of grease on the forkends and the throwout bearing to ensure zero noise/longevity and a little grease in the pilot bearing in the flywheel.

I'm glad my car no longer makes that sound.

are you speaking of the drivetrain whining? that's exactly what mine sounds like now.

Aye.

Mine also sounds like that. I blame my light flywheel and ready to grenade trans that was run without oil.

I switched transmissions, while keeping the lightweight flywheel, and the sound went away.

Guess it's my trans then. Not surprised.

you can hear it good here:




and then my bird chirping brake pads.


Mine got really bad when my diff ran without oil, im assuming the extra load trying to drive a bad diff wore out the bearings in the trans.

Update:

Swapped the clutch and tranny. Lube all the point indicated below, it's silent. I'm pretty sure the noise was the TOB rattling on the fork.

Any idea what cured it? I always assumed mine was related to rattles from the TOB on the fork, but never knew what could really be done about it. Always use new parts, and grease. Always have the noise anyway.

when I pulled the trans I took a look and the TOB; still looked in good shape and spun smooth. However, when sitting there on the input shaft there was a good .125-.250" of play on the fork. I'm pretty sure that particular noise was the TOB rattling on the fork since there was zero grease on the fingers of the fork or the slots on the TOB. It made a similar noise when I would jiggle it around.

When I put the new bearing on the fork after greasing both heavily, there was less apparently play and it made no noise since it was dampened by goo.

All my other noise are gone now too with this new trans so my drivetrain is finally quiet.