JOHN DEERE 630

[mkr730]

Bought a JD 630 thats been sitting for 3 years. This tractor has had a very rough life spending most of its life outside. I was able to pick it up for 1200 so I took it home. I have it in the shop with engine completely disassembled. The bad. The head was not cracked but previous owner ran it for years with the right side manifold gasket. The hot exhaust cut the exhaust bolt down to the size of a 12 gauge wire. Also ate away the exhaust port on the head which left a very low spot and thin thin wall. With all that and 2 broken bolts I will be searching for a head. On the clutch side instead of purchasing a new clutch driver when needed he chose drive small steel rods the size of welding rods to take up the slack. Good thing I have a 620 parts tractor with useable crankshaft. The block looked really good and pistons were (JD 630 GAS stamped on them and part number A 5555 R)My question for you guys, when you do a major overhaul on these tractors do you do anything to the oil pump? Surprisingly inside the crank case was really clean. Oil pump screen was clean. I know if I pull the pump I will have to shim it back to tolerence. Do these pumps fail often? Transmission looked clean with good gears. I feared it would have been a rust bucket with the amount of water in it. Prolly 5 gal. Bearings feel pretty tight but the water has me wanting to replace them as well. Give me you guys thoughts on what to look for on my journey through rebuilding a nice 630. Thx

 

[NY 986]

I envy you as I always wanted a 630 but lacked the money for the big dollars they normally command. Anyways, congrats and I will be interested in the advice given just in case I find a good project 630 like you did.

 

[fixerupper]

Seems like the Waterloo two banger oil pumps usually last for the life of the tractor when treated right. I have a 630 with at least 15,000 hours running on the original pump. It pegs the gauge when cold and settles back to the high side of the ‘m’ on the gauge when hot. It’s a family tractor always shedded and oil changed regularly. A 630 that’s been treated bad might be a different story.

 

[MSD]

If you have it apart take the oil pump out and remove the screen and clean under it. It is dirty. Also take the plate off the bottom and clean up the gears. Get the gasket from JD for it and that is all the shimming you have to do.

 

[Mike M]

I'd keep your original cyl. head if it does not have any cracks in it. The bolts and eroded away top port are EASY fixes and most all will be that way. Many rebuilt exchange cyl. heads have had internal cracks repaired too.
To fix what you have. If eroded away bad enough on exh. gasket surface they weld up nice with machinable nickel rod. If not too far down just mount in a milling machine on an angle plate. Run a fly cutter across the intake and exhaust ports leveling them up. While in the mill also drill out the broken off bolts. A mill is really nice to drill out bolts as it will not walk and you can easily feel when it goes through the bolt and then the gap before the hole bottom so you do not drill through that.

 

[mkr730]

Just took the cam shaft out. It doesn't look worn to the untrained eye. Are they prone to need resurfaced at rebuild? I took it out replace cam bearings. As far as tranny goes which transmission bearings are prone to fail? While inside I am planning to replace the PTO seal that leaks gear oil in PTO. What esle can you guys tell me to look for?

 

[Mike M]

As far as cams very little data for them seems to of been published. If you could get specs for it that may make it easier to measure for wear. But in general these slow speed tractors also have light valve springs and don't generally tear up cams.
Now on the tranny the lower countershaft bearings seem to take a beating as does the retaining nut on the left side resulting in way too much shaft end play. When looking at the races for wear the hard to see without removal top sides of them can be chewed up and the easy to see lower sides can look good. But any of them can get bad from rust and metal shavings running around in them after all these years. On the pto where the seal is there is also a bushing that good chance is worn too.