JD 4630 Quad

I have a 4630 quad range in the shop for a touchy clutch pedal. I checked the clutch pressure and it is in spec. The problem is when you let off the clutch its more jumpy than our 4440. I checked the clutch valve springs, looked good but replaced them anyway. Put it back together and still touchy. Any other things to look at? It does have a combine motor in it (466). With the clutch in pressure drops to 0 slowly letting out it starts to move around 15psi and jumps to 140psi. thanks

I hope u find the problem because my 4630 is the same way and I could never find out why so I finally gave up. Had a mechanic split it and he said there was nothing wrong that he could find

Since they run 3 clutch plates they tend to be jumpy...I have tryed many different things to solve this problem and still can't make one smooth out...

Tim, when I was going through the clutch valve I noticed the lower clutch spring was longer and compressed easier than the spring the parts book calls for. I?m not sure if someone just threw a spring in or what. The new spring made it a little better but still not a smooth as our 4440. Never thought about the 3 clutch plates. Thanks.

Several years ago (25 I think) I tried hard to smooth one up,, I tried different springs,,polished the valves,,tried different clutch adjustments.split it several times....spent a couple days at it,,never got it to were I liked it...finally decided that it wasn't gonna get any better....one thing I have thought about since,,and never tried was orfacing the clutch pipe adapter in behind the operating valve,, taping it to an Allen screw and drilling it out to let oil in slower..just a thought that you might want to try...#23 in the pic

I have a 4430 that a few years back developed the same problem. I tried everything we split that tractor at least 3 times that summer. It was so bad that the front end would almost come off the ground when you let the clutch out. Put new clutch disc an the floater plate no help. Checked the valves and the springs in the valve body that Tim put on here could not find anything wrong. Finally we noticed were those pins #4 and 10 on Tim's parts page. If I remember correctly it is the #4 pin that is on the main clutch valve. There is no keeper on those pins after assembly the head of those pins rides against that outer valve body an that keeps them in the clevis. The head of the pin over all those hours ( approx. 7000) at that time had worn a grove in that outer housing an the head of that pin would catch when you released the clutch pedal. The grove was not that noticeable But was somewhat rough. I just smoothed it up with emery cloth put it back together and it has been smooth every since. It has 9900 hrs. now. Sounds almost un believable but that is what fixed mine. I had a good friend who was a Deere mechanic and until we came across that nothing else worked good luck.

You'd think Deere would have a service bulletin
on this problem---sounds like it is kind of
wide spread.

Maybe they want to sell a new tractor instead.
Jim

A few years back there was a discussion on the YT J.I. Case forum about how Case engineers had to add a longer chamfer to the leading edge of a spool valve to smooth out the hydraulic clutch engagement on their 800/830 Case-O-Matic transmissions.

I have no idea if that would apply to a Quad-Range. The clutch pedal on a Case-O-Matic is more like the inching pedal on a Power-Shift transmission.

I can see how that could have been Jeff,,and I never thought of that...

Yes SS55,,the same thing should apply to the Deere system..all good Ideas that I will use on the next jumpy 4630 that comes though..

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