New owner JD 790

[redmtnex]

Howdy all! Just bought a 2001 JD 790 4x4 30HP with 360 hours, 7 backhoe, 70 loader with additional hydraulic grapple (think that's the name) and a box scraper R1 rear tires and not sure about the fronts, ag though. Used it a bit last weekend and am very happy! Its very clean and has extra controls for an auger or what ever. It has two cylinders for the 3PT. The backhoe is presently installed. This coming weekend I may attempt to take it off and try out the box scraper.
Anyhow I will eventually be looking for a tiller. Everyone around here is asking $800 plus for one.

So here it is, all my newbie questions!
1- What size tiller will this tractor handle?
2- Can any 3pt tiller be installed, pto compatibility etc?
3- My front tires are not real great and could be replaced, where do I buy them?
4- I read somewhere here about a shim mod for the loader controls, can someone point me in the right direction?
5- What about insurance, through my auto carrier or homeowners?
6- Aux lighting, I know that in normal light mode I can power additional lighting but where do I find that circuit, is there an easy plug in somewhere or do I have to hack into the wiring?
7- I would like to add some water ballast in the tires. Where do I get Calcium chloride and how do I get it into the tires?

Thanks
Greg

 

[charleyfarmall]

1. Personally I'd use a 5 foot tiller
2. Any 3pt tiller will work, but check to see what the gearbox rating is. King cutters are good economy tillers
3. There are several on line suppliers for ag tires, google is your friend. However, how are you going to get them installed? I'd look for a local ag tire store/ repair shop. If you have a good dealer, use them. Let them take care of loading your rear tires.
4. I don't know about the loader
5. homeowners.
6.Add your own circuit off the battery or starter, use an inline fuse. Search in the Customizing threads for Deere Lights. There may be a light kit available from the dealer that plugs in. Deere's auxillary kits aren't terribly expensive.
7.See #3. You can't do it without equipment, and you should use Rim Guard ( Rim Guard - Liquid Tire Ballast ). Your local Coop can do it and the tire change at your place even.

 

[kebo]

Here are links to two threads on it. If you search on "shimming hydraulics" in this JD forums, you will find several other threads on the subject. I added a shim kit to mine and upped the pressure to 2500psi. That is the max so don't exceed that. You will need a 0-3000 PSI gauge with the proper fitting to measure the before & after pressures. I don't have the JD part number for the shim kit handy, but I know it's mentioned in some of the threads already. It's an easy mod to make and well worth it.

http://www.tractorbynet.com/forums/.../134666-long-term-effects-790-hydraulics.html


http://www.tractorbynet.com/forums/john-deere-owning-operating/36404-790-lift-capacity.html

 

[YesDeere]

Good answers so far. I used a five foot tiller with no problem. Once hooked up to a six footer and it didn't like that. As far as shims go. It is well worth it. Don't go too high with it. One pack of shims will do. There is a detailed thread with pics and part numbers. Just search

 

[redmtnex]

Thanks everyone for the replies.
In my operators manual it states for light position "C - (Field Position) Headlights, taillights, and any optional work lights ON. The other positions do not mention optional lighting. That leads me to believe that there is a wired harness circuit already in place in which to run aux lighting. There is a fuse (4th position) specifically for flood lamps. Besides a service manual is there anywhere I can obtain a wiring schematic? I will look around for unused harness plugs and do some testing.

 

[YesDeere]

When I put lights on the rops of mine, I used an unused plug by the left rear fender. Only rub was the rear work lights were only on when the headlights were on. Easy to do though. No real good way to hide the wires for a clean look.

 

[redmtnex]

When I put lights on the rops of mine, I used an unused plug by the left rear fender. Only rub was the rear work lights were only on when the headlights were on. Easy to do though. No real good way to hide the wires for a clean look.

I think that wire is explained in this tread http://www.tractorbynet.com/forums/john-deere-owning-operating/134613-jd-790-what-connector.html with a schematic. I think for my purposes I will not be using the built in circuit. Reason is I may not always want the ignition switch in the run position to have aux lights on. My solution will be two circuits, both powered via light relays, the relay being activated from a couple of switches on the dash. Only problem with this setup is someone might turn on the lights accidentally and drain the battery. A solution to that would be a second key switch to safeguard those circuits. Main power will come directly from the battery, fused of course. The use of light relays eliminates having to run heavy gauge wire to the switches.

 

[RoyJackson]

When I put lights on the rops of mine, I used an unused plug by the left rear fender. Only rub was the rear work lights were only on when the headlights were on. Easy to do though. No real good way to hide the wires for a clean look.

I think Deere's thoughts were, if it's dark enough to use the work light, it's dark enough to use the headlamps.
There is a pigtail (under the seat, if I recall) specifically for the rear work lamp. If you buy the Deere worklamp (about 40 bucks), it'll plug right in. There are also holes (just aft and inboard of the flasher lamps) in the fenders to mount the worklamp.

See the attached .pdf file for shimming the pressure relief valve.
Couple hints:
Don't go overboard shimming the valve...one shim kit is quite sufficient.
When removing the cap (circled), watch out for the spring and othe small pieces popping out...these fly pretty easily. I strongly suggest you do this job with the tractor parked on a nice clean floor.

 

[redmtnex]

Thanks Roy for the pdf. I ordered the shims and the rubber bumpers for the 7 backhoe. Believe it or not I can not find anything else in need of replacement. I did though order the brackets to mount the SMV sign onto the backhoe. Ordered the sign on eBay for real cheap! You all have been a great help, thank you very much! I will build a gauge to check that final pressure but it will be a few days out before I get to that. We are getting ready to do a kitchen remodel and the county is making us upgrade our septic system Just found out today that I have to add 140 feet of leach field. The 790 is here just in time! :thumbsup:

 

[YesDeere]

When I put those lights on I took the path of least resistance. The double blizzard two winters ago was bearing down on us and I wanted lights. Mainly so I didnt hit anything while clearing a lot. It worked for that and woodsplitting later on.

I think your going about it the right way. On my 4310 the light switch works without the ignition on. That is nice.

About the leach field. My 790 had the #7 hoe as well. Very good for what it is. The new to me 4310 has the 47 hoe on it. Just a bit beefier. But still a kick in the a** to dig a field with it. I did about a 125' field with it and was on that thing the better part of a weekend. The guy I know who sucked my tank out before I started had a good laugh when I told him I was going to dig with the Deere. Said I'd be all weekend. I was. Oh well I told him that's all I have. Got it done but if I had to do it again there would be a mini ex rented.

Just saying...