This post is dedicated to the R-155 manual transmission . All you guys with the 5 speed should read through some of this stuff .If you have additional...
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CHECK YOUR CLUTCH ADJUSTMENT !!!!! DONT WAIT FOR YOUR THROW OUT BEARING TO BLOW UP. Some of you are just reading this now and may be too late
This will help you determine if you need a new bearing .
Your throw out bearing is semi-centrifical which means its only pre-loaded when you push your pedal down .When your foot is off the clutch pedal , the throw out bearing is NOT suppose to turn and shouldnt be pre-loaded against the pressure plate fingers .The adjustment is made under the dash at the pedal and master pushrod adjustment .As your clutch wears in , the throw out bearing begins to turn all the time and wears the bearing out premature unless a clutch adjustment is made .
The chirping you are hearing is the point in time where your throw out bearing begins to touch the pressure plate fingers .The pressure plate is spinning and the throw out bearing is stationary . Your clutch is starting to wear in a little and this is an early warning that its time to re-adjust the clutch and is how these clutches have operated for very long time .
When this happens , The sound will only be noticeable in neutral with the truck running . When you push the clutch pedal down , the throw out bearing will start turning and the chirping will go away .Some people believe that the bearing is suppose to turn all the time which is totally incorrect .The throw out bearing is "not" designed to be preloaded against the fingers of the pressure plate . Other members make adjustments to their clutch without knowing how a diaphram style clutch works and tell the world they fixed the chirping but really all they did was make the bearing turn all the time - the noise went away so it must be fixed " WRONG " Wrong Wrong .
A diaphram style clutch works like a pivot . As the clutch disc wears in , the fingers on the pressure plate move towards the throw out bearing . Anyone who has changed out their clutch will notice as you are bolting down the new pressure plate to the flywheel , the pressure plate fingers will move outwards towards the release bearing until you have all the bolts torqued down . The same thing occurs as your clutch disc begins to wear in.THE PRESSURE PLATE FINGERS MOVE TOWARDS THE RELEASE BEARING .
Even if you have a new clutch installed at a garage , make sure the free play adjustment is done correctly since some mechanics skip this step and actually use procedures used by Ford to fix your Toyota and accidently send you on your way with a spinning preloaded bearing .Your new bearing is "NOT " going to last as long if its preloaded against the pressure plate fingers because preloading increases as the clutch disc begins to wear .This means that when the clutch is new and adjusted correctly , there is no weight on the bearing . As the clutch disc starts to break in , the weight on the bearing doubles .Print out the FSM free play adjustment and take it to the shop thats doing your clutch job so they have instructions to follow .
There are other issues with the throw out bearing . The above issue is only one of them .