JD 790 First Impressions & Questions!!!!

MaxxB · Jun 9, 2011

Well, got the little bugger home last night. Its a 30hp version with a 70 series bucket. EDIT: I forgot to add: 300 hours!

Most of my tractor time has been on a JD 5000 series and sketchy ol farmalls (no offence IH, just trust me when I say sketchy). Coming from the larger JD, I was doubting myself and the tractor going to a CUT level machine. Reading a bunch on this site particularly gave me confidence moving forward. That and our 15 acres is better paired with a smaller machine.

Anyway, I was got some time on it and I have to say it really exceeded my expectations. Plenty of power and despite only 2 ranges you can really creep (I love low gears) and much to my surprise I was able to go down the road at a good clip (which is great because I have field work down the road). The tires are supposedly filled, but I still need some more rear weight.

The one thing i failed to pick-up on when test driving it was a grinding/racheting sound from the right brake. (when you push both pedals its not as noticeable). I am gravely concerned by this. I did see in another thread here that it could be as simple as glazing on the shoes. I'm really hoping that is all that it is, which I find hard to believe because it sounds more like a gear sound to my untrained ears.

I'd really truly appreciate any insight on this! If the vote is its only brakes...then i can rest easy.

When it comes to wheel weights, are they gonna be JD specific or are there generics too? Are they more or less universal in size or specific to models as well?

Last ( for now!), where can I get a grill guard...mine didn't come with one.

godaddy · Jun 9, 2011

Wheel weights r very exspensive! I would get or make a ballast bx or buy a implement for the back(tiller/bx blade) something like that. Brakes should not be gone with only 300 hrs. Mine has 950 and brakes still good. Need 2 get a shop man. 4 it, so u can do the work on it yourself. U can get on the jd website and look @ how to get to the brakes. Not hard! I would change all filters and fluids so u know where u stand with that.

MaxxB · Jun 9, 2011

Thanks! Are you suggesting that its not the brakes

The other thread I linked to the guy said his had low hours too and others suggested possibly just brake glazing....

I cant stress enough...if its just brakes...i can rest easy. if its something else......

bp fick · Jun 9, 2011

Might try eBay for a grill guard. Lots of fabricators making and selling on there. It's where I got one a few years back.

godaddy · Jun 9, 2011

Pull that plate that is covering the shoes and check. Nothing to it! No not saying not the brakes. Probably glazing as said. 1things 4 sure, if it's not the brakes "IT'S GOING TO BE EXSPENSIVE" I bet, being a John deere! Good luck!

MaxxB · Jun 9, 2011

Will do....but I want to be clear. In the thread I linked the gent there described the sound as grinding/ratcheting...his symptoms are identical to mine.

Would there be any chance of differential failure which would only make a sound when one brake was applied?

godaddy · Jun 9, 2011

I doubt u have a gear issue! It would more than likely do it all the time, not just when u put on brakes. Unless it's the spider gears in the rearend. That's why I said change all your fluids. The screen under the bottom of the tractor 4 the hydrolic system can tell u alot( metal shavings, chunks of metal,etc). It holds alittle over 4 gallons of fluid. Change front gear oil also. Nothing like knowing when the fluids/filters were changed and the right stuff put it in it. U probably got yourself a good tractor that will suprise u with ? it can do. Keep us up on it.

Mechanos · Jun 9, 2011

MaxxB said:
...The tires are supposedly filled, but I still need some more rear weight...

For what it's worth... I have a 955 which a similar sized tractor with the 70A FEL (virtually the same as your 70 FEL). For the 955, the 70A loader manual recommends liquid filled rear tires, 3 wheel weights per side (the weights are about 60lbs. each) AND about 700lbs. on the 3pt for ballast. Seem like a bit of overkill to me... but that what the manual recommends. So, yes, you're going to want to add some more rear weight.

I believe the 790 and the 955 use the same rear wheel weights... last time I checked, they were about $130/ea. That's $780 plus tax just for wheel weights. Over $2/lb. for weight seem pretty expensive to me. I've seen some used weights for sale in the past that were selling for $2.50/lb. They are kind of an odd shape and not very "universal".

godaddy · Jun 9, 2011

That's why I said I would just buy me some kind of implement and fill my rear tires with fluid. Weights r crazy $$$$$$$$$$$$$$$$$$!

Cabman1939 · Jun 9, 2011

To the best of my knowledge, a J.D. 790 and 3005 are the same tractor. So when you look for weights and things this should broaden you scope. Please correct me if I'm wrong. I can take it.