2nd Gen. throwout bearing

[bldn10]

I have a whistling/whirring/chirping(?) sound coming from my flywheel area that stops when I engage the clutch; I think it is the throwout bearing. Is it worth the trouble of pulling the tranny just to change the bearing? What is the ultimate result of a bad bearing?

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[lateapex911]

Yup...sounds like a throwout bearing to me.

Is it worth the trouble? Depends. Most will say it is, some will say don't bother.

In my eyes, it's the right time to put a clutch in it too, and not wory about either for awhile.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[bill f]

One consequence of throw out bearing problems (yours sounds like it might be dry, possibly from misadjustment) could be worn pressure plate fingers.

Constant contact with the rotating pressure plate fingers will dry up the bearing over time, which is possibly why you are hearing it rotate. When dry, it won't rotate freely, and then it will wear the fingers prematurely.

Change it.

Good racing.

Bill

[steve s]

your problem is not the throwout brg. but the input shaft brg. in the tranny or the countershaft brg. in the tranny, but anyway the tranny needs rebuilding. sorry about the bad news. on the other hand you can live with the noise and wait for it to come apart at the track.
if it was the throwout brg. it would have gotten worse when you press the clutch.since the noise goes away when you press the clutch you isolate the tranny from the engine. so the problem is in the tranny.

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steve saney
it-7 /it-a #34

[lateapex911]

My bad...I read it to mean when he pushed the pedal in. ooops..sorry!

Do the pilot bearing too while you're there!

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[bill f]

Me bad, too. I didn't read the message, and I'm wrong. It is the input shaft bearing, as stated above.

Bill

[bldn10]

Since I may have misused the terminology let me say it this way: when I depress the clutch pedal the noise immediately stops. It will sometimes go away on its own.

BTW at what front brake rotor thickness do you guys usually replace them. Using a crappy caliper mine are about 21 mm.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[its66]

Bill,
Does the noise stop as soon as there is pressure on the pedal(i.e. pressure on the bearing)? Or do you have to actually press the pedal enough that the clutch plate is actually disengaged before the noise stops? Almost the same sound and symptom, different causes. Usually, if the noise goes away as soon as any "slack" in the system is taken up, it would point to the release bearing. Whistling and chirping sounds more like release bearing. From my limited experience, the bigger problems (gears and trans bearings) are noises i would describe as a growl instead, especially while under load.

If you do replace the throwout bearing, be sure you get the right one. They were different for early vs. late chassis.

Jim

[jrx13]

Ok this is probably an illegal mod but I had heard to use a turbo transmission throwout bearing because it is supposedly stronger? Anybody know if this is true?

-Jack

[bldn10]

The tranny is grinding a little from 4th to 5th and I have a SpeedSource rebuilt one sitting by so I am going to go ahead and replace it. I may take a shot at the pilot bearing and will probably replace the throwout, whether that is the noise or not. Jim, how do you tell one tranny from another? I don't see any distinguishing markings.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[its66]

Bill,
The transmissions are the same. The mount and the pilot bearing are differnet early vs. late. (the rod in the clutch slave is different also.) If Speedsource built your car from an early shell, you probably need the early throwout bearing. The early one is 27.25 mm thick from the surface where it meets the pressure plate to the flat "friction" surface that slides into the clutch fork. The later ones are slightly thinner (3-5 mm maybe)

On the pilot bearing, be sure you don't drive it in too hard. You might damage the plastic cage that the rollers ride in. don't ask how I know..lol

Jim

[bldn10]

Jim, this is your comment that I am wondering about: "If you do replace the throwout bearing, be sure you get the right one. They were different for early vs. late chassis."

I assumed you meant different for early vs. late tranny - no? Did you mean early vs. late engine/pilot bearing? My car has a late engine and, I assume, pilot bearing, so wouldn't I want a late throwout? The car came w/ an extra, used throwout and it seems to measure about 26.5mm so it's probably an early one. The only markings on it are JAPAN, NTN, and B. Is there any way to tell if it is any good?



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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[its66]

Bill,
I worded that poorly. I should have stated that the throw-out bearing needs to match the clutch slave cylinder and pushrod. When SS built my car (also an 87 chassis), they retained the early clutch slave cylinder. When I installed the brand new 89 throw out bearing, my pedal was at the top of the range before the clutch even bagan to grab. I removed the trans again and found the difference. I have the pilot, pressure plate, and disc for an 89, and the thorwout for an 86....

If you need more, email at jcohen at wdi dot com

Jim

[bldn10]

FWIW I pulled the tranny today and I see what Jim is talking about re the 2 different throwouts. The tranny has "87" written on it and is the same as the new one so I am going to go all S4. The bearing that was on it is very different. Where the other one measured approx. 27mm, this one is closer to 23 and bears the markings JAPAN, NTN, and RRRR. And, boy, is it bad. I can hardly turn it w/ my hand and I can feel it grinding. It is dry as a bone. Could there have been be a power loss associated w/ it? I think the fingers are OK - although there is some discoloration on the tips, they feel square and unworn.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[bldn10]

I know all of ya'll are losing sleep over this so you will want to hear this. :-) I ordered an S4 bearing from Mazda Comp Parts and it is clearly the thicker one, as Jim said. Its markings are JAPAN, NTN, and HHH and it is part no. FE84-16-510. $18.25 delivered. The one I took off, that had gone bad, was the thinner S5 one.

Jim, what SS car do you have?

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[Rob May]

Jim has the 1999 SARRC championship car. It had an undefeated record that year. Pole, and won every race. It was previously owned by Donis Horne. The "Fifth Gear" car. White with a red bottom.

[bldn10]

I remember when that car was for sale; I even called about it and have pictures of it if Jim wants them. My car is probably a close kin - it was originally Marcello Abello's, then whent to Alan Ludwig, and when I got it in 2/04 it was painted red below the beltline just like the Horne car. Rob, I was also looking at Wade's car - do you know if it sold? Jason Sessions' blue car is up here in Memphis now - bought off ebay for a song. We ought to have a SpeedSource Registry. I bet Syl would let us do it on his site.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[its66]

Bill,
Rob is actually right about my car. My steering wheel still calls for his hands late at night. http://ITForum.ImprovedTouring.com/smile.gif
I think Wade's car ended up in Atlanta. Tom Fowler has been seen lurking around with it lately. I think it is one of his customer's cars, but I'm not sure who. Tom is sill have trouble with this longitudinally mounted, pistonless engine which spins the back tires stuff... :P

There's a thought, a SS registry.

Rob..rumors are just flyin' around down here. You should call me sometime. (before I make the rumors more interesting than they are and spread them further..LOL)

Jim

p.s. Bill, save those pics, I'll get them from you. Who knows, they might be worth $$$ someday..