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928 transmission swap out

 
Old 02-08-2011, 01:36 AM
  #31  
James Bailey
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Ah having trouble visualizing....under car stationary , foot off clutch car in gear....I assume engine is running, how long will the car be stationary ???? Also the release bearing will be spinning all the time just whether it is under load or not.
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Old 02-08-2011, 01:47 AM
  #32  
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Yeah, yeah, I figured you'd catch that, Jim. Didn't have room to put 'stall or burnout' in that little box.
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Old 02-08-2011, 12:55 PM
  #33  
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The release bearing should not spin if your foot is not on the clutch. Any time you press the clutch pedal, it puts a load against the bearing, and then it spins- but it should be stationary when there is no load on the pedal, or it will die quickly....
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Old 02-08-2011, 01:10 PM
  #34  
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I guess the confusion is that there is two parts to the bearing. the outer portion that is fixed to the lever arm, is stationary, so when the clutch assembly rotates, its spinning around that bearing, right? thats one bearing. Then, there is the short shaft, which slides through the center of the bearing, but doesnt really touch anything (just a little grease in there to reduce some friction if the short shaft touches the inner walls. (guided through the guide tube that is fixed mounted to the bell housing)

So, it seems that the clutch throw out bearing is always spinning. I doesnt know if the short shaft is spinning inside of it or not. (meaning clutch in or out) when you push in the clutch, the pressure of the lever is on the outer rim of the T/O bearing and is still spinning because , again, its attached to the arm, but now is spinning underload. ( preload due to the clutch being depressed)
when released, the arm lowers the pressure plate down to make contact with the discs, but the T/o bearing is still spinning just the same. Its always spinning.

Am I right here, or is there something connecting the inner shaft with the throw out bearing . I dont thin there is . they are not connnected and only occasionally rub, i would imagine, probably only on assembly!

So, any throw out bearing noise, would be associated to that same bearing that is always rotating, but makes noise under the load of pushing the clutch in.



Originally Posted by svp928 View Post
The release bearing should not spin if your foot is not on the clutch. Any time you press the clutch pedal, it puts a load against the bearing, and then it spins- but it should be stationary when there is no load on the pedal, or it will die quickly....
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Old 02-08-2011, 01:12 PM
  #35  
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+1

letting clutch out with in neutral is the same for the clutch and torque tube. it doesnt know you are in any gear. so, letting the clutch out in or out of gear should be the same as far as the torque tube is concerned. but, anyway, my car was jacked up in gear, just so we could hear that nice grinding noise of no teath on that first stage input.

Originally Posted by James Bailey View Post
Ah having trouble visualizing....under car stationary , foot off clutch car in gear....I assume engine is running, how long will the car be stationary ???? Also the release bearing will be spinning all the time just whether it is under load or not.
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Old 02-08-2011, 02:18 PM
  #36  
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I can hear the wheels turning!
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Old 02-08-2011, 02:36 PM
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You might be right. This style is clipped to the clutch pressure plate, which is bolted to the flywheel and always spinning.

(illustrations are 87-up single disc)

Twin is similar, bearing clipped to PP.

Am confused how it works.
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Old 02-08-2011, 02:47 PM
  #38  
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Right since the clutch arm does not spin...part of the bearing MUST. When the bearing starts to drag it can spin the race and wear away the pressure plate spring fingers also puts wear on the raised knubs where the arm contacts the release bearing.
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Old 02-08-2011, 02:53 PM
  #39  
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Yes, I see that the spring washer actually fastens the TO brg to the pressure plate, so it is always spinning with the clutch. SHoulda known- Jim is right!
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Old 02-08-2011, 03:11 PM
  #40  
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Yep. Relay, Relay, Bearing always spins, Relay
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Old 02-08-2011, 07:03 PM
  #41  
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I thought so! Good, that means noise is torque tube some bearing noise resonating from the transmission, but thats unlikely. its the torque tube that is spinning in the bearings and making a racket!
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Old 02-10-2011, 12:20 AM
  #42  
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Updated table, for posterity:

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Old 02-22-2011, 01:27 PM
  #43  
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It was the transmission. noise was resonating through the tube, into the bell housing where it was amplified. new transmission in, everything quiet as a mouse!
Its back in action after I put some new hardward on the exhaust mounts which were toast.
Thanks
Mark
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Old 02-22-2011, 01:52 PM
  #44  
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We take the TT out and put it on a bench with it tied down, nothing else connected to it.
Then take about a 6-7 foot length of sturdy twine and wrap it around the actual part that spins, like winding up a top, once it is wound up, pull it as hard as you can to spin the actual shaft and listen.
That is the best way to test them that I have found.
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Old 02-22-2011, 04:54 PM
  #45  
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thats a good idea! but you can feel a lot, just by spinning. no axial play, no radial play, AND we didnt have all the stuff to do the rebuild, no other time would work to do this, so we just put the pretty decent torque tube, originially, back in . what a dream, hearing it start up with no noise! that trannie is cooked!
Now, what to do with it. 5th gear has a bunch of chewed up teeth, but nothing really destroyed like I expected. it drives in 5th gear no problem! but no gears at all. so, all the gears you cant see below, dont connect to the 5th gear because its mating gear is destroyed.one tooth looked about 1/2 gone and the others are just jacked up quite a bit. i figure the rest of the gear box is in good shape, so maybe just a 5th gear and mating gear below??

anway, next winter rebuild project. Or maybe a Greg Brown disasembly demo at the next Sharktober fest at Mark Anderson's in LA.



Originally Posted by blown 87 View Post
We take the TT out and put it on a bench with it tied down, nothing else connected to it.
Then take about a 6-7 foot length of sturdy twine and wrap it around the actual part that spins, like winding up a top, once it is wound up, pull it as hard as you can to spin the actual shaft and listen.
That is the best way to test them that I have found.
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