D4 cat 7U clutch rattle

Was pushing brush and suddenly got a loud rattle from clutch housing. Managed to return to my truck but clutch was not engaging or disengaging properly. Removed the top cover over clutch housing and at idle the yoke assembly was vibrating wildly. if I pushed the clutch lever fully forward the clutch brake will eventually stop the clutch from turning but takes several seconds. the coupling assembly was very hot to the touch(actually burned me and would sizzle if spit on). there seems to be brass fillings covering all components in the housing area, very fine almost like a grease.

there is a pillow block assembly ( looks similar to main bearing caps on an engine)between the coupler and the collar assembly, it was extremely hot.

Is there a bearing or bushing in this pillow block? I have a parts book for a 6U but it does not seem to show the pillow block, is the 7U different or am I misreading the diagram?

I adjusted the clutch in AM, as I have several times over the last few years that I have owned the cat, and it worked fine all day. I put 8 hours on it before problem started.

Is this the clutch itself going or a bearing or bushing in the mechanical part of the clutch control that is the problem?

The clutch was working fine all day no slipping and shifted well.
 
Going out on a limb here, sounds like the pilot bearing in the driven plate. If that wallows out from a bearing failure, it will vibrate and the drive links will rub on the bell housing creating heat in no time.
 
Have you got a Serviceman's Reference Book and Parts Catalog for a 7U series ?

I'm working from an earlier series "2T", complete set of all manuals. Forget what I said about the drive links, these smaller models do not have those in the flywheel clutch assembly, but they do have a pilot bearing. The "plate assembly" looks to have a roller bearing in the center, look for bearing parts or any sign of metal fines, pieces, rub marks etc. inside the bell housing compartment. The parts manual will give you the details on this assembly, SRB will tell you how to remove and install. Not sure without taking it apart to some degree how you could check the plate assembly. With what you describe, you would have to find something in there, sounds significant and about to fail. I had it happen on a larger model with a dry clutch that is different then the D4 model.
 
on further inspection the flywheel is loose and flops when you engage the clutch.

Does this support your pilot bearing theory?

I guess I'll have to pull out the clutch, do you know if it can come out the bottom of bellhousing if I remove the stump pan?

I only have a parts catalog for a 6U.The only bearing I see is further forward beyond the plate assembly. would this be the pilot bearing?

there is also a nut that tightens the plate assembly onto the shaft, could this have spun loose? Should be a cotter pin to lock it in position.

Hope some of this makes sense.


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Makes sense for the most part. Check the adjustment collar/cam links, your lever should have a distinct snap over when engaging the clutch, that should tell you if adjusted correctly or in the ballpark. With what you describe, something is loose, so you should be able to find what it is. The flywheel is loose, do you mean the flywhweel attached to the engine crankshaft ?

To remove the flywheel clutch, you have to take off the transmission cover assembly from the top. You can't do this from the bottom and if ever taking off a belly pan, be very careful doing so, big and heavy, will crush or pin you if it falls on top of you. Your 6U parts catalog may help, but you really need the SRB for the 7U series, check ebay, cat classic literature - they were reprinting these for whatever cost, I forget but manuals for a 7U should be out there. I am not sure of the changes that may have been made between the various series of D4 tractors of this era.
 
I'll try track down an SRB.

The plate the clutch cams press against is moving around in relation to the plates(disc) closer to engine.
 
Yes, that will be very helpful, SRB, Parts Catalog and Operators Instructions are the titles of the 3 manuals you should have for your serial number tractor. Your tractor will belong to a serial number group of tractors and the range of S/N's is typically stated, be sure to match these up.

Sounds like a pilot bearing, or something in the center of the plate unless something else has come apart to allow this free play that should not be there. Once you have the top cover off, before you go head first into the removal, see what you can find, inspect what you can see, look for metal pieces, fines, friction material fines/pieces etc. I've done this work on larger tractors of about the same era, dry clutch, not all that complicated to remove.
 
my late model 7U srb and dry clutch shows a pilot bearing in the flywheel-the clutch is removed thru the top clutch cover opening. but you have to remove the drain plug from the bottom of the clutch compartment and remove the screw that secures the lower part of the yoke
 
Thanks, that sounds like the problem.

Ordered an SRB on line.

Old machine but in good shape so I'll do my best to keep it that way.
 

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