Mid 80's 850 tractor questions.

[Rmally]

Hey folks,

I have access to use a friends mid 80's model 850 tractor. It has a 5' bush hog and mid mounted mower. I need it to help maintain a 2,000 foot long gravel crusher run driveway (particulary after heavy rains).

I have offered to buy a box blade but have never used one and thought I'd reach out to see what I need to look for. I was going to look used so what would you recommend? a 4-5 foot one. The tractor does not have a FEL or weights so not sure if that plays into things.

Is a box blade the best implement for this job? I'm new to tractors and complete newb at having a gravel driveway.

Thanks for any assistance.

 

[beenthere]

Some searching on TBN will give you some good ideas.. 2000 ft of drive will be a test of your blade skills be it a rear blade or a box blade.

Here are just a few links that may help..
https://www.tractorbynet.com/forums/attachments/122762-beginners-guide-using-box-blade.html

https://www.tractorbynet.com/forums/attachments/87771-box-blade-gauge-wheels.html

https://www.tractorbynet.com/forums/customization/68781-rear-blade-gage-wheels.html

I maintained a long gravel drive for 40 years.. and a key to success was working it up deep to get the fines mixed with the larger gravel, spread it evenly, and then before it dries out, pack it down tight so when a rain comes it doesn't wash away the fines.
Driving over and over with the car or truck did that packing very well.
Just pushing dry marbles of gravel around on top will not last very long before pot holes appear.

Good luck. May need wheel weights to get good traction with a blade or box.
Gauge wheels will make the job more productive and a much neater job.

 

[jeff9366]

A 35-year old tractor is going to be problem prone.

As a new operator you are going to be unaware of operating limits and potential trouble indications.

If the tractor packs up, what will you do?

 

[CobyRupert]

There's a lot of threads here on TBN regarding new tractors that are problem prone and spend the majority of their lives back at the dealer getting serviced, fixing poor dealer prep practices or waiting for parts. Like any problem you encounter in life, and there will be some, you will simply react and figure it out.

As Beenthere alludes to, material management is almost a whole topic unto itself, almost separate from implement choice.

You want a heavier implement so that it actually can cut into the material rather than scrape along the top.
At the same time you don't want to overpower the tractor.
With an JD850 at 2400 pounds (without weights), it's hard to say if the tractor is a bit light for a 5'. Probably depends on the material and how much you're biting off in each pass. 5' would probably cover wheel width for a box blade; and a rear blade unless angled.

There's pros and cons with any choice.
I used a rear blade with angle, tilt and offset functions. Excellent for ditching, crowning, more "coarse" work. A bit tricky for smooth grading / filling in holes.
I've never used a boxblade, but people here on TBN with box blades swear by them to maintain gravel roads. They seem easiest (most forgiving) to collect material and fill in holes, but I'd expect they're tricky (but not impossible) to make a crown or a ditch. Being able to tilt/angle/offset a rear blade has advantages. With a box blade one has to adjust the link arms (or get a hydraulic (cylinder) link arm on one side) to tilt.
Adjusting the blades angle of attack also become important. This is done by adjusting the top link, or getting a hydraulic (cylinder) top link.

 

[jeff9366]

Some JD850s are 2-WD, some 4-WD.

 

[Quebecguy]

Regularly borrowing a friend's tractor seems to me to be a good way to ruin a friendship.

 

[crashz]

The 750s, 850s and 70 series are good tractors. Very basic, but are generally reliable and easy to learn on. Beautiful mowing machines. But as Jeff mentioned, its a 30 year old straight shift tractor. My concern would be the clutch on this machine. Pulling a loaded box blade or straight blade and hitting a rock could be hard on it and if the clutch is weak to begin with, could mean issues.

I also think that if you are new to grading with a blade or box, that an old crash box transmission will add to your frustration. And when your are frustrated with and old standard shift, you grind gears. And get more frustrated.

 

[Rmally]

Hey guys,

Thanks so much for the input, I will be buying a new/newish tractor late this year or in the spring. We are currently building a new home on the property and my friend has a new JD tractor. He offered to leave his old 850 on my land to use if I needed it thus my question.

He said it mows great but he has never used a box on it. Yes I'm new to tractors, his new one is hydrostatic (which is what I will be buying) but if this 850 will be tricky to use I may just keep using my lawn mower and cheap pull grader. I'm going to try it out on Saturday then decide on weather or not to buy a box blade for it.

I didn't even think of all the issues y'all have mentioned so I'm glad everyone chimed in....it probably saved me from buying something I don't need yet.

Thanks again!

 

[beenthere]

My concern would be the clutch on this machine. Pulling a loaded box blade or straight blade and hitting a rock could be hard on it and if the clutch is weak to begin with, could mean issues.

I also think that if you are new to grading with a blade or box, that an old crash box transmission will add to your frustration. And when your are frustrated with and old standard shift, you grind gears.

Put many a gravel drive in with the old "crash box tranny" and no real reason to shy away from them. May be fragile from wear, but that is a different issue to face when borrowing someone's rig. But perfectly capable to work up a gravel drive.. just may take some "learnin". Learned on an 8N Ford and a rear blade..

But I wouldn't borrow someone's tractor.. best to ask them to drive their own tractor with some compensation or take it out in trade.

 

[Rmally]

Guys, just so we are clear I am not borrowing a friends tractor....well, according to him... He has a brand new one ( 3 months old now) and he would like to keep his old 34 year old one at my property so its out of his way. He is the one telling me to use this rig, and in return I was offering to buy a box for it if I was going to use it for my driveway. He said it's just going to sit outside his barn and never get used. He doesn't even want to sell it because he said something will go wrong with it and then he would feel bad. I'm not the type to borrow anything let alone a tractor but he's telling me it will help him out by keeping it running and freeing up some space. I was just asking for advice on the box and this particular tractor not trying to stir a nest over borrowing someones tractor. Thanks again for the input on these older models and what to expect.....but please don't worry if we are ever neighbors, I promise I won't ask to borrow your tractor