JD-630 Clutch That Grabs

The clutch on my JD-630 grabs when I move the tractor in gear. There is no way I can feather the clutch for a smooth engagement. It is a mess when backing or inching forward. I have tried to adjust the clutch without much luck. The end play on the crankshaft is correct. The clutch handle seems to have some play and then all of a sudden the clutch will grab.

Any ideas what is wrong?
 
Mine tended that way. Someone here once suggested putting some "wavy washers" under the 3 adjusting nuts and this helped mine a lot. I think those are called Belleville washers. These sort of cushion the engagement. Could be the other things was well, but I like to start with the simplest and cheapest solutions . . .
 
I would agree with Tim, is there more noise with engine running & pulley not spinning with clutch disengaged?
The 3 spring washer's are a must & clutch parts inside in good shape. Is there up & down movement with the pulley?
I would be looking at the support bearing & race on the crank shaft.
 
I installed a Belleville washer under the three clutch adjusting nuts
on my JD B and it cured the problem. It was real bad jumpy before.
JD part number R21647, pkg. of five. Wasn't expensive.
 

The spring washers do help. On my tractors I go one step further although it is somewhat involved. This is something to try if you have access to machine tools. I tighten up all the slop in the linkages by welding and drilling as needed. And in particular, the pivot pin for the clutch lever is welded up and re-machined for a fairly tight press fit into the clutch lever. Often the bushing for the lever is worn right through and there is wear in the lever beyond the bushing. So if that is the case the lever gets welded up and re-bored also. The end result is a clutch lever that has about as much friction for movement as the throttle lever. When it is like that it is very easy to partially engage the clutch and smoothly get going, or just inch forward or reverse a little. I have been putting grease fittings in the end of the pivot pins, and the pins are drilled to direct grease between the pin and the bushing. But generally the fit is so tight I can’t get them to take grease. I don’t know how long those fits will last because I don’t use the tractors very much. Being tight like they are, at least dust and grit can’t get in there. So I think they will hold up fairly well. Just getting new parts won’t produce a fit like these are when I machine them. The improvement in operation I thought was well worth the effort.
 
How are your metal disk parts in the clutch ? If they are shiny like a mirror or glazed they will grab bad. I like to sandblast the faces of all the removable metal plates and driver disk. Short of that at least a good scuffing up with sandpaper will help a lot.
And after all the above and below mentioned ideas are done if it still grabs throw some graphite powder in on the clutch.
 

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