Finally got back to the 72 AMX 360 project.  When last I left you, I was fighting a weird clutch noise issue. Here is my last post(s):

I'd like to say I figure it out, but I did not.  Car runs, drives, shifts great but has a VERY loud vibration/noise that happens as soon as the throw out bearing touches the clutch fingers.

I sent the new RAM Borg & Beck clutch back to the factory and they said it checked out fine.  So, I bought a new Centerforce Diaphragm Kit#DF271739 and ANOTHER new TOB.  Pedal pressure is so much nicer than the RAM, but the clutch noise is still there, if not louder.

I had a fixture made with a dummy input shaft/snout that allowed me to see what was happening when the clutch was engaged or to see what was going on it there.  Since it still made the noise without the trans in place, I know it has noting to do with the input shaft or snout.  As the TOB touches the clutch fingers the bearing begins to turn and it starts to vibrate on the snout.  This continues all the way thru pedal movement to the floor.  The old RAM clutch seemed to get better as the pedal was pushed, but the Centerforce stays consistently loud.  It does not look like the TOB is binding on the fork and seems to move freely along the snout as it's supposed to.  There are no wear marks on anything that I can see.

So...now I am wondering if perhaps I have a balance issue with my flywheel.  I am wondering if someone has replaced the flywheel at some point in time and it is out of sync with the harmonic dampener.  The engine does not seem to shake or vibrate excessively but it is kind of hard to tell with the big cam...  I just finished tearing it down again for the sixth time...and pulled the flywheel off.  The part number is 319-7219 which according to Planet Houston AMC (my eyes!) is a mystery flywheel that may or may not go on a 360.

If I do choose to buy a new flywheel, do I need to change out the dampener as well?  And, if I do replace the set, can I get away with just having the dampener, flywheel, and clutch assembly balanced?  I know, I know--I should do the entire rotating assembly for it to be right, but I really hate to pull the engine and tear it down.  

Anyway, sorry for the book--hoping someone can give some new insight on the problem.

Thanks,

Jack

 

Pilot bushing, or the TO bearing is too loose on the trans snout, so that it's not centered when it touches the fingers, and wobbles around like a random orbital sander.

I don't know if there's a spec for clearance from the snout/bearing retainer to the ID of the "non-moving" portion of the TO bearing. Loose enough to not bind, but not so loose it can go off center.

In 1970 AMC went to a slightly smaller throw out bearing, which is mentioned in PAS. It seems that this information is not known at RAM because all of their kits come with the larger TOB for a pre 1969 car. I guess this makes sense in a way since the larger bearing was the reccomended performance version. I have told RAM about this several times and even had a warranty serviced for a new clutch, but I don't get the feeling that they ever did anything about the incorrect TOB in their "67-74 clutch kit". If they have left it as is for the heavy duty kit I suspect they did not for the standard kit either. Perhaps Centerforce is using the same information?  

Unfortunately, my bearing made a rattling, grinding type noise and the only way to get rid of it was to push down on the pedal and take up the slack in the linkages. When I took it apart, the TOB had failed, along with the clutch, and they had worn away the bearing retainer on the trans until it simply broke through. 

If you need the correct bearing number for a 70 and up clutch I can find it.

Chris

PS: I happen to have my maintenance log on the coffee table, so here goes on the part numbers. The larger 69 and earlier type is #N1489. The smaller 70 and up version is #N1491. #1489 is the one that came in the 88499HDX kit and I would imagine they put the same one in the 772 kit also.   

Thanks for the input.

I have checked and rechecked the alignment of the bell housing to the block, both the hole concentricity to the crank, the parallel of the trans mounting face, and the perpendicularity of the face to the crank. I have also checked the transmission snout/input shaft perpendicularity and concentricity. Every think is within a few thousandths. I have also check (and rechecked) the run out of the flywheel relative to the block in both directions and it is also within .005" which tells me that the flywheel is not warped or the crank flange bent.

Like, you I was sure it was an alignment issue with the trans input shaft so I made a fixture that replicated the transmission input shaft which I bolted onto the back of the bell housing to take the trans out of the equation.  I left the spline off the shaft so it stayed stationary and did not turn in the pilot bearing. The TOB started to chatter the second it touched the clutch fingers even with no real pressure put on the clutch pedal.

Thanks for the input.  

The pilot bearing is new and at one point I suspected it as well so during one of my many tear downs I coated the tip of the transmission input shaft with blue Dykem to see how much engagement I was getting.  Took the engine up to 3500 rpm with the clutch pedal in/out.  There was some missing dye but it was very minimal (and probably mostly from trying to wrestle the transmission back into place.)  

Do they make ball bearing pilots for AMC engines? 

Tom, thanks for the response.

The old snout was badly worn and so I had a new snout made out of P20 steel for the bearing cover (I own a machine shop that does high tolerance work).  The snout diameter was  turned to 1.313"on the nose and the ID of the TOB (Centerforce # N1491) is 1.311".  So, .001" of clearance radially. I actually bought the bearing first and then had the snout machined to size.  

Maybe that's too tight?  My thought was that since the TOB moves in all three directions with the clutch fork (side-to-side and back and forth), there should be no binding unless it hits the inside of the clutch fork (and it does not).  

Pilot bearing is new and I feel good about the input shaft alignment.  This is my third TOB and they all make the same noise.  I know the noise is coming from the TOB, but I don't think it is a bad TOB causing it (if that makes any sense...)

Thanks for the info.  I originally had RAM B&B kit # 88772HDX (VERY stiff) and the TOB had the correct ID (although a little oversize, I thought), but it was very tight on the fingers of the clutch fork.  At this point in time, I still had the original snout on the trans bearing cover and was using a new clutch fork I bought from American Parts Depot since the fingers were worn on my original fork.  When I did my first road test, that is when the vibration problem started.  My first thought was that RAM had sent a bad TOB in the kit so I changed it out to a Centerforce (#N1491) and repaired my original clutch fork and went back to it.  Still same noise. I measured everything which checked out.  I changed the plastic clutch linkage bushings out for bronze and had a new linkage adjuster made that pushed the clutch fork in a nice straight direction. I sent the clutch and TOB back to RAM to check and they said they were fine.

SO, I bought a diaphragm clutch kit from Centerforce (DF271739) and another TOB (third one if you are keeping score...).  Same noise, maybe even a bit louder.

IDK, something is causing the TOB to vibrate/chatter as soon as it touches the clutch fingers.  Since everything measures out correctly and I have replaced every part (except the flywheel and dampener) I think I have a weird out-of-balance issue that is not enough to shake/vibrate the engine, but enough to cause the TOB to chatter.  I am out of ideas other than that.

Jack

fair enough, I know you have done a million things. The one thing I am not 100% sure has been done is that there are TWO bearing retainers and TWO different throw out bearings. You have measured the TOB's and said that they seem ok, but a bit loose. I would look up the inside diameter of the two bearings and also see which bearing retainer you have. The car being in pieces might mean that you have an early bearing might be either early or late. There could still be a mismatch. 

If you have done this, bear in mind it is my wife and I's anniversary and I have not been able to check back in every thread! 

Good luck, but I, and others, still say all roads probably lead to the TOB! 

Chris 

PS: The difference in inside diameter is a few hundredts of an inch, but it enough to cause the TOB to not function properly. You have mentioned "a bit loose" and it could be more significant than you are thinking. 

Also you don't mention dial indicating the flywheel. If the crankshaft flange was not true, even slightly, then the outside of the flywheel will amplify this. Easy enough to check by removing the inspection cover and setting up a dial indicator on the outside of the flywheel and rotating the crank.

Have you put a dial indicator on the face of the flywheel, clutch off, & spun the crank to see what it reads? The base of the indicator on the block, the indicator riding on the face of the flywheel.

To go along with what Trader mentioned in a post.

Thanks, I have not tried that test and will have to put everything back together first.  I pulled the flywheel off to see what the part number was to make sure I didn't have a 304 or 401 flywheel on it.

I will say that the wear pattern on the face of the TOB is consistent and right in the center.  But that does not tell me if the surface is contacting the clutch fingers uniformly.  

Thanks for the reply and congrats on the anniversary.  

Just to clarify, the ID of the first TOB from RAM I used had an ID of 1.325 which seemed big to me.  The second (and third) TOB I am using now from Centerforce  has an ID of 1.313" and I had the bearing retainer snout machined to an OD of 1.311" so I have .002" of clearance across the diameter (I think I reversed those numbers in an earlier post).  Anyway, I'm not sure what the factory spec was originally, but .002" seemed fairly tight to me and should not allow for a lot of movement on the snout.

My clutch fork does not have spring tabs and there is no spring behind the TOB.  Honestly, I'm not sure how they would attach to the clutch fork I have.    Not sure I have seen anything like that in any of the assembly diagrams I've looked at.  Is that something AMC included from the factory?  

Yes, I have indicated the flywheel and checked concentricity around the perimeter and flatness on the clutch side.  Seems to be within and few thousands in both directions.

I don't think that's enough clearance. one thousandth is tight, for any part. I can only guess from here, but I think .005" would be more appropriate, or even .010". It's essentially a dry sliding part, grit, or anything, could wedge in there, do some improptu machining in there, raise a ridge, etc. 

Keep in mind a TO fork itself is highly tolerant (nice way of saying sloppy :-) I wouldn't count on ideal concentricity.

I have a T14 and I think a decent but used TO bearing sleeve I could try to get good measurements on if you need the info.

On the AMC setup ,the BEARING is separate from the press-fit SLEEVE. Are you swapping sleeve+bearing assemblies, or pressing bearings onto the same sleeve? I'd try a looser sleeve and see what happens.

If it doesn't shake in neutral at a few thousand RPM under any one of the possible clutch conditions, it's not balance.

The wear pattern is consistent around the face of the TOB. I feel pretty good about alignment and measurement of everything and don't think that's the issue.  

That being said, I won't say I disagree with you on having the wrong fork. Everything was in boxes when I got the car and the original fork does not have a part number stamped on it anywhere which makes me think it is not stock.  I did try a new one from American Parts Depot at one point and it was definitely not correct.

Based on info I've read (on this forum and elsewhere), it seems the important thing for 1972 is to have a fork in which the pivot point, linkage divot, and bearing opening are basically in a "straight line" and gives a 2:1 movement--I think.  I'm open to correction if that is wrong...

With my fixture I was able to see the TOB move along the dummy snout and as the clutch pedal was pressed.  The fork seemed to move the TOB in a straight path and the fork fingers seemed to stay close to the center of the TOB.  If the fork was too long, it seems that either the TOB would rub on the inside of the fork opening or the fingers would be off-center.  If it were too short the fingers would be off-center in the other direction.

Honestly, if I could find a fork that I knew for certain was a direct factory stock or OEM replacement for a 1972 360 AMX I would probably buy it and try it.  

Thanks,

Jack

Thanks,

Jack

I guess what I am thinking is that it is not the TOB that is out of balance but the Flywheel/pressure plate. And, that is causing a slight wobble which causes the TOB to chatter on the snout.

That's probably a reach since the engine does not seem to shake or vibrate, but I am simply running out of things to check at this point...

I found shop across town that will balance the flywheel/clutch assembly as a set.  Going to call them and see what they charge for that.

Thanks.

Thanks Tom,

It would be great if I could get a factory spec (or close to it) of what the clearance between the TOB ID and input shaft snout OD snout should be.

You may be right on it being too tight, but I will say that way back when I did the first road test I had the original input shaft snout on the car which was way undersized from years of wear and the noise was still there.  Of course, that may of been a symptom of the TOB being too loose...

I'm buying off-the-shelf bearing + retainers as a set that are already pressed together.  They all seem to be close to the same ID.  But, I could take the one of the TOB's I have and open up the ID a bit and see what happens. 

I am trying to only change one variable at a time which sucks sine I have to tear everything down and build it back up between tests...was a lot easier to do when I was 20 years old...

Tomj is correct about that tolerance, it's way to tight! When you get dirt and facing material built up on there, it will bind up. Do you have any kind of high temp lube on the bearing support? It shouldn't be dry. Same goes for the splines and the pilot bearing. Measure the non worn part of your original bearing support and go from there. You should not have any wear up near the transmission.

I was thinking about this today and came up with a few things to check. Check the TO bearing face. If it's a flat face bearing, it should be used with a 3 finger (Borg and Beck) clutch and a diaphragm clutch with beaded end tips on the fingers. Some diaphragm clutches have flat fingers and you have to use a beaded (face) bearing. If you have a beaded bearing with a B&B or beaded diaphragm clutch, it will want to walk around or chatter.

Another thing to check is the finger height of the diaphragm to see if the fingers are out much. This must be done with the pressure plate bolted to the flywheel like it's normally installed. The same goes for the B&B clutch. If the fingers are out to much it can cause your problem.

One other thing which is a long shot, try to see if you can spin that bearing with a load on it, like in a mill to see if there's something possibly wrong with the bearing itself. So much of the aftermarket stuff out now is junk and there's only one or two places making it all so there could be a bad batch of bearings even though they came from different suppliers. Wooster Kevin replaced his TO bearing after just 3 months in the car! It was starting to squeal when he pushed the clutch in like it was dry.

Thanks for the advice--a lot of good thoughts.  I do have high temp bearing grease on the snout, bearing ID, spline, and pilot bearing.

The non-worn OD of my old snout was 1.310.  When I machined the new one, I asked the forum how much tolerance I should have and got a response that the factory spec was .001 to .002" so I machined the new snout to 1.311 since the new Centerforce bearing was measuring 1.313" ID.  

Since the car has not seen any real driving yet, the interior of the bell housing is really clean so there is not any debris to cause TOB binding.  Over time that may change so your point is valid.  And, even though it is a tight clearance, the TOB does slide freely on the snout and turns like it should.  Also, should note that I had the noise issue with the old snout and the first RAM TOB which had an 1.318 ID (I think...) so that would have been .004" of clearance radially per side.

I will check the pressure plate finger height when I get ready to re-assemble everything.  Since this is my second clutch kit and the noise was present with the first clutch kit as well, it seems unlikely that is where the noise is coming from, but I will check it.

The TOB I used last is from Centerforce (p/n N1491) which they specified with the Centerforce diaphragm clutch I have (p/n DF271739).  The clutch fingers are not flat and have a "bump" on them and the TOB has a flat face.  This is the second Centerforce TOB I have tried.  The first was from RAM.

Thanks,

Jack

My only real reasoning is that you might do well to use the clutch of your choice, buy the right bearing for it, get the correct matching bearing retainer(the larger 69 and earlier one is available from APD, fyi) and fork, and be done with it. No more measuring clearance, speculating on TOB types, etc. The flywheel seems to spin true from the sound of it and you have already checked the bell housing and block mating angles, so you are almost there. Not much left, frankly. 

I truly do wish you a quick resolution to this, I know how frustrating these kind of things are!

Chris 

What you're referring to would be runout, not balance. If it was out of balance, it would shake. It is not shaking? It is not out of balance.

Runout, you can easily test. Put a dial indicator on a machined flywheel surface (outside clutch plate bolts is fine), mark it, rotate the engine, note the maximum runout on the dial indicator. I don't know what the spec would be but someone here will know or its a "standard" value (.010 or less I assume). 

By "runout" imagine a record on a turntable, with a pump under one corner, it would wobble as it rotates.

EVEN SO, even .100" of runout (YOU'D NOTICE THAT! lol) on the outer edge would be a tiny fraction of that in  close to the trans clutch shaft. Ask an expert, but I suspect if you had clutch fingers off or uneven .010" where the TO bearing touches, that wouldn't be the problem anyway. It's not THAT critical there.

I would stop grasping a straws and get methodical.

*** verify snout to TO bearing sleeve clearance. You said you've made it .002". THat seems excessively tight to me, but what do I know. VERIFY THAT. IF too tight, FIX IT. 

*** with the car up on jackstands, the pushrod from the Z-bar out, crawl under with it running, press the clutch fork in by hand. Can you make it growl? Pump in your hand? Light press? Hard press matter? Push it "on center", then off to each side. 

*** if you don't have a super extra duty bright muh-fuh excellenter-then-heck-squared pocket LED flashlight, buy one now. Maybe a 10W gooseneck LED lamp. Or one o' them new-fangled borescopes. They're super cheap now. Both!

Oh this is a big issue, haven't seen addressed yet --

*** is the trans clutch shaft centered on the crankshaft? Have you aligned the trans in the trans hole?

That stated, ANSI B4.1-1967 Running and Sliding Fit, Class 3 - 1.19" to 1.97" shaft is 0.001" to 0.0026".

 

[QUOTE=   I found shop across town that will balance the flywheel/clutch assembly as a set.  Going to call them and see what they charge for that.  [Quote]

It might make more sense to have them spin balance just the clutch disc and pressure plate. which should have been done at the plant that made those two parts.

I'm in complete agreement with everyone else's opinion that .001 to .002 is inadequate clearance between the throw out bearing and the trans input shaft housing's snout.  On an aluminum snout it would chew that  up quickly.

The throw out bearing only rotates when in contact with the pressure plates  "diaphragm" or "fingers". 

It certainly doesn't need engine bearing clearances to do that.

I wish I knew the correct clearance amount that is recommended.  I recall being able to feel the throw out bearing wobble on the input snout. 

It's been a while since I read the beginning posts, so if this has been mentioned already just disregard it.

Is the clutch disc splined inside diameter correct for the input shaft of the transmission?

Example:  Ford sourced T5's use a 1-1/6" diameter 10 spine. AMC T5s used a 1-1/8" diameter ten spline.

https://www.centerforce.com/products?car=66-5213-1970-0" rel="nofollow - https://www.centerforce.com/products?car=66-5213-1970-0

If you scroll down you will find both the 1489 and the 1491 TOB listed with ID's. I also did find a listing for the bearing retainer OD for the earlier 69 and previous TOB bearing retainer. That measurement is 1.125", which if you take the ID of the matching #1489 Centerforce bearing(1.416"), you get almost 3/10"! I highly doubt that a measley couple of thou's is going to be adequate. 

The information on the AMC clutches seems to be just about the priesthood, so we all need to be able to figure this out for ourselves. I did not find the bear retainer OD for the 1491/post 69 unit, but this should give at least some idea. I do know that the difference between a 1489 and a 1491 inside diameter is .101", or about 3/32". That was enough for my TOB to work properly, albeit with a bit of noise, BUT it ate right through the steel retainer over about 11k miles to the point where it fell apart, just from whatever touching it was doing by jiggling around loose. 

I hope that helps!

Chris  

PS: Here is the specs from Jegs for the Centerforce 1489. Note bearing retainer diameter:  https://www.jegs.com/i/Centerforce/183/N1489/10002/-1" rel="nofollow - https://www.jegs.com/i/Centerforce/183/N1489/10002/-1

PPS: The take away is that the TOB does not even come close to touching the retainer, if it does, you have a problem

I'll try to answer the last few questions above:

1)  I have checked the flatness and concentricity of the flywheel.  As an engineer, I know my way around calipers, gauges, mics, indicators, and fixtures and feel fairly confident that all critical measurements and alignments are where they need to be. That's not to say I couldn't have made a mistake, but I have checked everything multiple times and just can't find anything that seems excessively out.

2) I have tried moving the clutch fork with my hand and the TOB does make noise as soon as it touches the pressure plate fingers and even before the bearing starts to turn. As more pressure is applied, the bearing starts to turn, but the noise does not stop.  

This is why I was suspecting a balance issue:  If everything measures out when the engine is off, then  something must be happening when it is turning to cause the TOB to vibrate excessively. I did talk to the balance shop and they said they would need the entire rotating assembly to balance everything. They did say that since I changed pistons, bearings, connecting rods, and had the rod bearing and mains surfaces turned, I could have altered the factory balance. However, they also said that if the engine is not shaking or vibrating at high rpm, it is probably not a balance issue.

3) Seems that most opinions are that my clearance between the TOB ID and bearing retainer snout OD is too tight.  OK, I will accept that as soon as I can get a good number of what it needs to be.  

As I noted above somewhere, the factory snout measured 1.310", the two Centerforce TOB's measured 1.313" and 1.3135", and the RAM TOB measures 1.318", and the old TOB that came with the car measures 1.315".   So if I take an average of all of those I get 1.3148" which means that, relative to the original factory snout OD of 1.310", the clearance would be .0048", so let's call it .005" on the diameter (or .0025" per side when centered).  That would be more than double what I have now.

But, if my clearance is excessively tight, why would that contribute to the noise?  If anything, it seems that less slop would make it quieter, if everything is in alignment.  Is the thinking that, when the engine is running, the extra clearance would allow the TOB to better self-align against the pressure plate fingers?  Again, if everything is in alignment (and I believe it is) it should not make any difference.

4) The clutch pressure plate spline measures 1.142" and the OD of the T-10 input shaft spline measures 1.124".  I had not measured that before and at first, I thought there was a potential for a .018" shift side to side, but since it is a spline, the movement is really not that great. 

5) The Centerforce TOB bearing I have (N1491) is what Centerforce specified to use with their Clutch kit (DF271739) which is supposed to go on 1972 AMXC 360's.  I like to think that they designed the ID of their bearing to sync with whatever the factory was supposed to be.  They do state that the N1491 TOB is supposed to have an ID of 1.315", but the two I have are coming in undersized at 1.313" and 1.3135" (using calibrated calipers from the QC department at work).  But, based on their spec'd ID of 1.315" and knowing the factory retainer snout OD is measuring 1.310", it looks like .005" of clearance is what they were probably shooting for. 

I don't have an issue taking stock off my snout (there's something I never thought I'd say...) but it is a one way trip because I can't add it back on.  I want to make sure I'm chasing the right animal before pulling the trigger on that.

What keeps the TOB centered to the clutch fingers/diaphragm? The clutch fork?

Is this a Centerforce dual clutch bearing?

The only transmission retainer/TOB tolerances that I have found so far are Mazda 0.008" maximum and Honda 0.005" maximum. No minimums stated.

Everything else states slip on smoothly??? Dry lube or thin moly grease lube.

The more clearance you have the greater the chance of the bearing getting cocked and contacting the rotating clutch. This I can see wearing the bearing and transmission retainer and making lots of noise!

There are self centering TOB's, but I doubt our older vehicles ever had these.

My opinion.

Chris, Thanks for the info.  

Yes...you're right: dealing with tens of thousandths of an inch daily makes it hard to not want to make everything perfect.  It's a blessing and a curse sometimes.  I was helping my neighbor frame a mini-barn last summer and trying to hold 1/16" center to center...I thought he was going to kill me.

I did look at the links you sent earlier and I am not sure I would trust the 1.125 number on the JEGS site.  I'm not sure what they are referring to, but it seems to me that the OD of 1970 and earlier bearing retainer snouts was in the 1.410 range.  I could be completely wrong about that, but pretty sure it is larger than 1.125".

I think my concern with getting too large on the clearance is that, as Trader mentioned, there is no centering mechanism for the TOB on these cars.  So, if the clearance is to liberal it could make the TOB hit the pressure plate fingers way off-center. It seems like that could actually keep the bearing from turning and want to make the whole TOB spin off center in the clutch fork. 

Yes sir.

https://www.novak-adapt.com/knowledge/clutches-etc/" rel="nofollow - https://www.novak-adapt.com/knowledge/clutches-etc/

I called Novak Technical support and Jim told me there is no one specification as there are many clutch designs, but older 60's and 70's are nominally 0.004" TOB clearance with stock parts and should not be over 0.010" on a smooth bearing retainer.

If you want more clearance between your snout & TO bearing, but don't want to reduce the diameter of the snout, hone the inside of the TO bearing. The TO bearing is cheaper & easier to replace if you go too far.

Another thought, not sure if it has already been mentioned. Bolts that hold the pressure plate on are correct? Not bottoming out in the hole?

That is a really good idea!  Especially since I have a whole herd of TOB's to choose from...

I changed out the original bolts for ARP and since they did not have a stock replacement for AMC I had to order a set for another brand.  I don't remember which, but I do remember measuring the hole depth to make sure they were correct length.  I also cleaned each hole out with a tap to make sure I didn't get a false positive torque reading.

Thanks for the suggestion.

Thanks, that is a good read.  

Also, appreciate you gathering info on the TOB clearance. 

throw-out bearings are intentionally sloppy, loose, and self-centering. They need to be, as the engine+transe shifts around, and in fleet quantities, and with years of warranty, auto makers have developed a very reliable system based upon LOW PRECISION.

The precision is in the machined hard parts. The flywheel, clutch cover, must be flat, concentric, with low runout. There are specs for those and they are easy to meet.

The second precision requirement is that the transmission clutch shaft/input shaft be in line and parallel to the crankshaft. The bell housing holds this alignment.

There's NO WAY that this is a "balance issue" if any of the facts relayed here are correct. Pushing the TO bearing onto the fingers by hand is not inducing a balance issue. It's just silly. 

The TO bearing assembly -- bearing plus fork sleeve -- weighs a half pound or a pound. It's centered on the trans snout. If it's off-center by .15" (half a third of an inch) the offset mass, relative to the entire rotating mass, is INSIGNIFICANT. 

The throwout bearing assembly and system -- fork, pivot ball, pushrod with ball end -- is DESIGNED TO MOVE AROUND and critically important, self-center.

Is there a reason OP is resisting making that snout tolerance something close to factory? .100" or something?

When the going gets tough you gotta start from First Principles.

Not trying to re-enter the fray, but this is how misinformation gets spread and Lord knows, AMC has never had any popular myths floating around.......

Chris 

AMXrated, we need to see pictures. Can you post some? 

I suspect that the problem is that the throwout beating sleeve is rotating on the bearing retainer snout on the transmission. Trader essentially pointed this out a few pages back.

If you are assembling/disassembling things to test, get some flat white (or flat black, or flat red) aerosol paint or Dychem and mist all the contact parts: snout, throwout bearing sleeve, T.O. bearing face, etc. You can remove it all later with solvent. Assemble, run, press the fork so the bearing presses on the fingers, etc. Then disassemble and photograph.

MY BET IS that the sleeve is rotating on the snout. It should not. The T.O. bearing is a thrust-face bearing. THe snout needs to move around on the snout, self-align for that last 10 thou of misalignment built into all real-world products that shift around and wear.

Without photographs we're all just waving our arms around in the dark.

I'll await photo evidence from here.

Here's an AMC throw out bearing assembly (bearing plus sleeve) on an AMC T-14, passenger car version, with some old fork. I barely wiped it off, excuse the mess.

The ID of the sleeve is greasy and dusty and cobwebby, and STILL has an easy 15 thousandths of play. Installed as shown, it sort of rattles on the snout. It's LOOSE.

The two things that this thread has uncovered as anomalous are:

* extremely tight sleeve to snout clearance.

* the fact that it chatters/whatever noise when you press the fork by hand.

Logic dictates that the problem is likely in this area.

Quite a 55 gallon drum of worms I've opened, apparently...

mmaher94087 wrote: Is that a photo of your bearing retainer?  It's wrong, wrong, wrong.

Apparently you didn't read what he wrote.

The spring in contact with the rotating crankshaft and transmission main shaft would want the two to rotate together. All kinds of issues from shifting to the spring wanting to wind and unwind depending on acceleration or deceleration. And then are the wear points of a hard steel spring were it does not belong!

If the transmission front main shaft or bearing is making noise - take the transmission apart and fix it.

My Opinion.

With pictures in the thread and some specs, maybe forum search could find that old thread with some info?

I tried a couple of suggestions above like painting the face of the TOB and pressing it against the pressure plate to make sure it was hitting squarely, and it was.  Also, mounted the pressure plate to the flywheel and measured the finger heights to make sure they were close and they were.  I also went ahead and installed a new pilot bearing in the end of the crank on the outside chance I had pressed the old one in a bit crooked--seemed unlikely, but it was a cheap change-out since I had everything apart.

I have been using Centerforce TOB's since I have a Centerforce clutch and that is what they recommend.  However, MoparGuy suggested I try a different brand on the outside chance I got into a bad shipment of the Centerforce bearings.  I had a new RAM bearing that came with my previous Borg&Beck style clutch so I tried it with the Centerforce diaphragm style using my test fixture and, while it did make some noise, it was not nearly as loud as it had been.  And, since I had the back of the bellhousing open, I figured I was probably hearing some normal noise anyway.

Based on that, I decided to put the transmission back in.  Now, I do not get the noise at idle (about 800rpm) but it does appear at 1000-1200 rpm and then stops at anything higher.  So, I must have some weird harmonic vibration occurring at 1000rpm that is causing the TOB to vibrate on the input shaft snout.  The RAM bearing is made a little differently and has a flatter bearing face than the Centerforce.  The ID is also about .002" larger.

At this point, I have no idea what to do with it and it seems pointless to keep taking it apart and putting it back together.  Since I am fairly certain everything is aligned and working like it should, I think I am just going to put the car back together and drive it this summer.  If it doesn't miraculously cure itself or get any worse...I'll take it back apart in the Fall and see if I am getting any wear patterns that might indicate a problem.  

Thanks

He has been having noise issues for years, and the offset dowels did not fix the problem.

We now know why and he is currently searching for a new bell housing. 

Thanks for the suggestion--that was one of the first things I checked.

The bellhousing rear face is within .003" of parallel in the vertical and .002" in the the horizontal with the crank face--not sure I can get it much closer.  The bellhousing input shaft hole is concentric with the crank as well.  The flywheel turns true (both flat and concentric) to the block as well.  Also, the input shaft snout is perpendicular to to the transmission mounting face, but since I am getting the noise without the transmission in place, the issue is not transmission related anyway.

That being said, however...I am keeping my eye out for another bellhousing and flywheel.  If I can pick them up reasonably, I may try to change them out just to see what happens. They are the only things I haven't replaced at this point.

Personally I have used 3200-3600 lbs. pressure  plate in my S/C for 38 years with 6 different motors with only having to reinforce the pedal push rod and belcrank (latter excessivly).

Last thought, if the 9 or is it 11? roller bearings behind the input, that the nose of the main shaft rides on are worn or if the nose of the main shaft is worn will allow the input to wobble! Just a thought, hope it works out

Mark

You either misunderstood or need a new transmission guy.

https://theamcforum.com/forum/uploads/14211/AMC_360_flywheel_holes_misaligned_2016-11-04_002.jpg" rel="nofollow - https://theamcforum.com/forum/uploads/14211/AMC_360_flywheel_holes_misaligned_2016-11-04_002.jpg

4.5 is the crank to flywheel pilot, not the transmission to crank pilot.

70/71 crank is 4.5. 72 and up is 4.65.

Frwilkins wrote: Yes, transmission guy put in new clutch and had flywheel turned. Still doesn't want to go into gear. I am going to his shop Monday to look at the flywheel.

You may want to do a runout on the face of the flywheel.  I've run into a couple cases in my life where a shop didn't clean the crank face of the flywheel or the hub on the flywheel grinder.  The flywheel didn't fully seat on the machine and was cut crooked.

Frwilkins wrote: Okay that helps a lot. So a 70/71 360 flywheel will have a 4.5 inch crank to flywheel pilot?

Yes