A Release Bearing Question and a Transmission question.

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Bib
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A Release Bearing Question and a Transmission question.

Postby Bib » Wed Dec 14, 2016 7:30 pm

Hi. With my car in storage for the winter, I'm going about fixing some things. One question I have is if the release bearing should be spinning at all with the clutch pedal out. It spins slightly and makes a squealing noise. This is a new TOB by the way. I've tried adjusting free play, and right now, my pedal is as far out as it can be, but the TOB is still catching the clutch. Could this be a slave cylinder issue? It's like the pushrod is putting too much pressure on the fork, because I can push the fork towards the slave cylinder and the TOB will stop spinning. Maybe I didn't push in the TOB enough?

I'm going to check actual freeplay specifications tomorrow.

Also, my transmission whines in neutral, first, second, third and reverse. I had the gearbox rebuilt with all new bearings besides the center counter shaft bearing, but that one seems to be in good shape. Running Redline MT-90 at the moment, haven't tried shifting with it, but I think the cheapo Taiwanese synchros are junk. Bearings were all Nachi and Koyo. It was doing the same with Royal Purple. Sounds kinda like a supercharger or straight cut gears, and pitch increases with RPM. It's a T50 by the way.

The gears looked to be OK, not really damaged.

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davew7
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Re: A Release Bearing Question and a Transmission question.

Postby davew7 » Thu Dec 15, 2016 4:53 am

I would check the master cylinder push rod. You need 1mm of free play at the M/C cylinder push rod before it contacts the piston . You need to allow enough travel for the M/C piston to uncover a port to release the pressure in the system. A quick check , break open the slave cylinder bleed valve to release any pressure that might be in the system. Also verify clearance at the slave cylinder push rod to the clutch bearing release arm. Most slave cylinder push rods are adjustable. Dave W

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Bib
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Re: A Release Bearing Question and a Transmission question.

Postby Bib » Thu Dec 15, 2016 11:36 am

davew7 wrote:I would check the master cylinder push rod. You need 1mm of free play at the M/C cylinder push rod before it contacts the piston . You need to allow enough travel for the M/C piston to uncover a port to release the pressure in the system. A quick check , break open the slave cylinder bleed valve to release any pressure that might be in the system. Also verify clearance at the slave cylinder push rod to the clutch bearing release arm. Most slave cylinder push rods are adjustable. Dave W

Thinking my clutch slave isn't the right size. I can't adjust the push rod and when the slave is on it's pushing against the fork. Will post pictures in a little bit.

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Bib
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Re: A Release Bearing Question and a Transmission question.

Postby Bib » Thu Dec 15, 2016 2:44 pm

Just the three washers make me think that either the fork or the slave aren't the right size.

http://i.imgur.com/oHo7COD.jpg
http://i.imgur.com/E3vTP9X.jpg
http://i.imgur.com/8RW7hnJ.jpg
http://i.imgur.com/mE7Cnq9.jpg

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davew7
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Re: A Release Bearing Question and a Transmission question.

Postby davew7 » Fri Dec 16, 2016 4:52 am

Just eye balling the pictures, the slave looks like a stock toyota one. If the rest of the system checks out. Pull the slave push rod out of the cylinder and shorten the push rod. Dave W

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Re: A Release Bearing Question and a Transmission question.

Postby SgtRauksauff » Fri Dec 16, 2016 12:06 pm

here's a picture of the brand-new Aisin clutch slave before I put it into my car:
Image

looks like yours might not have the feed opposite of the mounting ears..

yep, I found another picture of mine mounted:

Image

note, the mounting ears are opposite of the feed, where yours they are on the same side.. It might be a toyota slave, but i don't think its the right one.

--sarge

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jondee86
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Re: A Release Bearing Question and a Transmission question.

Postby jondee86 » Fri Dec 16, 2016 3:52 pm

I have never been able to find any information that specifies where the AE86 TOB should
sit in relation to the clutch fingers. Apparently some vehicles are designed to have clearance,
and are often fitted with a spring to make sure the fork pulls back far enough to get a few
mm clearance. Other vehicles are designed to have the TOB in light contact with the fingers
and (may) have a spring inside the slave cylinder to push the rod out and bring the TOB into
light contact with the fingers.

Having the TOB in contact with the fingers makes the clutch self-adjusting and ensures that
there is minimum movement of the clutch pedal before the fork begins to move. I suspect
(but don't know for sure) that the AE86 clutch is designed this way, as I have never seen a
spring to draw back the fork.

One thing that does happen with the slave cylinder when it has been in service for 25 years
with no maintenace, is that there is a buildup of corrosion on the bore, both behind and in
front of the piston. This can eventually prevent the piston from fully retracting, and cause
the point of engagement of the clutch pedal to get closer and closer to the floor. It can even
cause the piston to become stuck in the "out" position preventing the clutch from engaging.

How do I know this I hear you ask... because it happened to me and I only discovered the
cause after I had bought a new clutch kit and dropped the transmission :oops: :oops: The clutch
was actually fine, it was the slave that needed replacing. The piston was stuck so far up the
bore that fluid was getting pumped out of the slave and inflating the rubber boot, leading
me to believe that I had blown the clutch. No fluid on the floor until I loosened the boot :lol:

Cheers... jondee86
Give a person a fish, they eat for a day. Suggest they search before posting, and they learn a skill for a lifetime.

davew7
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Re: A Release Bearing Question and a Transmission question.

Postby davew7 » Sat Dec 17, 2016 4:35 am

I just check on Rock auto. It looks like your slave cylinder is from an FX16.
A new [with correctly located mounting tabs] AE86 slave is dirt cheap, and it appears to have an adjustable push rod. Dave W

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Bib
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Re: A Release Bearing Question and a Transmission question.

Postby Bib » Sat Dec 17, 2016 2:36 pm

davew7 wrote:I just check on Rock auto. It looks like your slave cylinder is from an FX16.
A new [with correctly located mounting tabs] AE86 slave is dirt cheap, and it appears to have an adjustable push rod. Dave W

Excellent. Yea the clutch checked out fine as far as air in the system went so i'll put in an order.

Thanks to everyone that contributed.

As far as the transmission goes, i'm not gonna worry about it for a little while. The bearings are all solid so it's not like it'll blow up on me.

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mad_86
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Re: A Release Bearing Question and a Transmission question.

Postby mad_86 » Mon Dec 19, 2016 10:53 pm

jondee86 wrote:I have never been able to find any information that specifies where the AE86 TOB should
sit in relation to the clutch fingers. Apparently some vehicles are designed to have clearance,
and are often fitted with a spring to make sure the fork pulls back far enough to get a few
mm clearance. Other vehicles are designed to have the TOB in light contact with the fingers
and (may) have a spring inside the slave cylinder to push the rod out and bring the TOB into
light contact with the fingers.

Having the TOB in contact with the fingers makes the clutch self-adjusting and ensures that
there is minimum movement of the clutch pedal before the fork begins to move. I suspect
(but don't know for sure) that the AE86 clutch is designed this way, as I have never seen a
spring to draw back the fork.

One thing that does happen with the slave cylinder when it has been in service for 25 years
with no maintenace, is that there is a buildup of corrosion on the bore, both behind and in
front of the piston. This can eventually prevent the piston from fully retracting, and cause
the point of engagement of the clutch pedal to get closer and closer to the floor. It can even
cause the piston to become stuck in the "out" position preventing the clutch from engaging.

How do I know this I hear you ask... because it happened to me and I only discovered the
cause after I had bought a new clutch kit and dropped the transmission :oops: :oops: The clutch
was actually fine, it was the slave that needed replacing. The piston was stuck so far up the
bore that fluid was getting pumped out of the slave and inflating the rubber boot, leading
me to believe that I had blown the clutch. No fluid on the floor until I loosened the boot :lol:

Cheers... jondee86



+1 Jondees is right that on that it does happen because it happened to me before, Slave went out and Clutch was stuck engaged,
i could shift but couldn't go anywhere due to stuck on, hahaha :lol: :lol: its funny after it happens, not during lol

Also Check for Driveshaft Carrier bearing or maybe the Rear end they could be making the noise
not the transmission, the rear does make a whirling sound also if its worn but if there extra
vibrations at higher speeds could be loose Driveshaft Bolts.


GL

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Bib
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Location: Eastern Massachusetts

Re: A Release Bearing Question and a Transmission question.

Postby Bib » Thu Jan 05, 2017 6:34 pm

Just an update: I installed the proper slave cylinder, and while I do have more free play in the clutch, the release bearing is still making contact. Maybe I didn't push down enough on it, I dunno. I'm not really gonna worry about it right now because the last thing I want to do at this moment is take the transmission off again to get at the bearing. Especially since it's cold.

mad_86 wrote:Also Check for Driveshaft Carrier bearing or maybe the Rear end they could be making the noise
not the transmission, the rear does make a whirling sound also if its worn but if there extra
vibrations at higher speeds could be loose Driveshaft Bolts.

I don't think it's the driveshaft since it's happening in neutral. I'm starting to think it's just gear noise. I'm shifting fine and the gears looked ok when I took the transmission apart so I guess that's all I can chalk it up to right now. Thanks for the suggestions though.

I'm going to install a TRD Limited Slip soon so if by chance it's the diff whining (which I doubt it is), I'll post an update saying so.

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