adjusting the clutch jm 284

[SPIKER]

Hi All

Just wanted to tell every one that I had to adjust my main clutch today, (380 hrs) lots of rough service since new. it still has some play left but is getting near it's lifes end per the adjustments left. I have all new parts to replace it so I'm not all that worried but it seems the OLD clutch disk (wear material) is not more than 100 thou thinner than the NEW one!? not sure if this feels right seems to me there should be a lot more clutch engagement with the amount of material left. anyone have any suggestions on min thickness and also does anyone have an actual specifications as to the min thickness of the clutch disk? I don't know HOW I could measure it with it installed accurately but just by stacking feeler gauges is where I came up with the ~ 100 though wear.

anyhow I didn't remember the camera so No good pics other than ones posted I took years ago that are on JohnS's web site.

mark M

 

[psj12]

Did you just adjust the linkage for pedal free travel or did you perform the adjustments on the clutch pressure plate?

 

[SPIKER]

hi PSJ:

I did both, freeplay was in range to begin with for the most part I just have no FEEL left for the clutch plate. there re 2 sections in the live clutch one for pto and one for main clutch if you adjust the main you also have to adjust the pto clutch to keep the range, (this will also effect the clutch travel on the linkage)

I should have taken more pics of it but didn't remember the camera.

what basically happens is the MAIN clutch bolts that pull on it also then pull main clutch plate up pulling the PTO up after the pto bolts/adjustments are engaged. so if you change the main bolts you also need to re-adjust the pto bolts as moving the main plate sooner/later will change where the pto comes in/out at.

hope that clears that up as clear as mud.

mark M

 

[RonMar]

Well since it dosn't use coil springs like most modern pressure plates do, I would say that maybe that pressed parabolic ring type spring they do use may be very sensitive to material lost from the clutch disc. IE: the applied spring force falls off quickly with increased travel for the plates to squeeze a thinner disc.

 

[SPIKER]

RON:

I agree with you're line of thought. The compression spring on these are not that great for a clutch as like you stated above there is not a lot of travel for them... I have all the parts to make up a new clutch complete except for the outer cast housing parts.

So everyone knows where we are coming from these clutch springs are a flat-cone type washer, (forget there name now?) (spring washer maybe) looking at the new ones there seems to be maybe quarter inch max compression on them.

mark M