4520 with RD990 finish mower

Sledge · Apr 24, 2013

I am looking to purchase a 4520 and a finish mower. I am considering the Woods RD990 and PRD8400. I plan on using this setup to mow about 9 acres of gently rolling hills. About 3 acres is mowed on a weekly basis and the rest will be mowed maybe once a month. The land is not smooth. It is mostly grass and some weeds. Is the RD990 too much weight for this tractor? Is there anyone running this combination that could offer some feedback? I want to run without the loader, so I was wondering if the front end will get too light using the 990. I will have to lift the mower occasionally to go around small hills and to travel to around the property. The PRD8400 also seems like a good choice and about 500 pounds lighter but medium duty rated. What do you think?

arlen4720 · Apr 24, 2013

How much do the units weigh? I have a mx6 behind my 4720. It weighs about 1100 pounds. I run with my loader and a 500 pound bucket on. If I didn't, I would definately want some weight in front.
But the finish mowers you are talking about are semi mount? Not hanging on the 3 point? I would still want SOME weight on the front.

SCS26WFO · Apr 25, 2013

Sledge, I can't give you any assistance on the comparison of the two mowers, but I can tell you what my experience has been with the RD8400 (about 16 years old and appears to be identical to the PRD8400). I pull it with a John Deere 970 (a smaller, lighter tractor than your 4520) with no weights or loader and the only time the front end gets light is with the mower lifted and cresting a hill at travel speeds. When mowing I have had no issues at all.
I’ll be of more help to you in about two weeks when my 4520 arrives. I plan on mowing with no weights and the front end loader removed as we have a lot of trees. I’ll post a follow up for you after I have mowed with it.
By the way, we have two Woods mowers, an early 1970’s belly mount and the 1990’s RD8400. Both have held up remarkably well with sub-standard maintenance (a shot of grease to the bearings every couple of months and blades sharpened each spring). I’m not as diligent on mower maintenance as I should be. Tractors are a different matter.

Sledge · Apr 25, 2013

According to the sales brochure the RD990-X weighs 1,333 lbs and the PRD8400 weighs 830 lbs.

eagle107 · Apr 25, 2013

I run a Woods PRD8400 with my JD 4520 and my neighbor runs a PRD8400 with his New Holland TC40D. My neighbor has been running his for 10 years with no issues; I have been running my PRD8400 for two years without any issues also. You pay a little more for the Wood equipment, but they do make top of the line mowers. I have also used the PRD8400 in our fields and cut down two to three foot tall grass/weeds with no issues; doing it in two passes. The RD990-X is the heavy duty model almost close to resembling a mini brush hog with swinging blades. The RD990-X might leave a little rougher cut than the PDR8400 from what my dealer explained to me when I was looking at both mowers. My dealer also stated that the mower is for a lot more fieldwork where you need to mow denser/taller weeds, light brush patches, sticker bushes, starter or small size saplings/seedlings/sprigs. If you do not want to pay the extra cost of the RD990-X, the PRD8400 would work fine for your needs; the PDR8400 is a stout mower. If money is no object, then go with the RD990-X.

Leejohn · Apr 25, 2013

I have the kubota l4240 and the 990. The 4240 is a good match up for the 990 and I think you would be fine with it. I don't use it with the loader on and can lift it real easy. You tractor is right at the same weight as mine.

SCS26WFO · May 6, 2013

I received my new 4520 on Friday and spent 3 hours on Saturday mowing with the Woods RD8400. I mowed with and without the front end loader and found no difference. The front end never got light when the mower was raised. I have no weights installed.

wolfpack2 · May 8, 2013

I have been using my RD8400 for 13 years and have had only minor issues (gear box failed after the first year and was replaced under warranty). For the first 12 years I ran it behind a NH TC40D and last year switched to a JD 4520 Cab. The front never gets light unless you are trying to accelerate quickly up a hill. I have upgraded the gauge wheels to larger pneumatics to prevent them from sinking into the soft clay every spring. I have been considering upgrading to the 990 as well because the 8400 barely covers the track width of the 4520 but I am concerned with the amount of scalping that will occur. I have to be careful in a few areas now and the wider mower will only make it worse.

gesimmers · May 13, 2013

I too am in the market for a finish mower to go with my Kubota MX4700 HST with R4s and I really like the Woods PRD8400. This has been a very useful discussion to read. I have been debating a RFM or ZTR and prefer the RFM options since I already own the tractor. I have 6 acres to mow (mostly old hayfield) with few obstacles except for an acre around the house. The other land is rolling hills that I can run side to side or straight up and down with the tractor. I have run bush hogs before but never a RFM.

Can you guys mow in Med range (Med Range - High for the HST+ folks) at 4-6mph with the 8400 or are you forced to run in Low range? Can you run Med range on hills and keep the RPMs up?

Can you get pretty close to obstacles with a RFM that sticks out a few inches beyond the rear tires?

Wolfpack2 were did you get the larger pneumatic tires and forks for your 8400?

Thank you

wolfpack2 · May 13, 2013

I get within a couple of inches of obstacle along the side of the mower and a couple of feet from the rear due to the overhangs. You can run as fast as the ground allows before you bounce off the seat. The mower will cut as fast as you can drive as long as you don't try to use it as a bush hog and mow down overgrown pastures. I usually mow in B range at max speed (~6 MPH) C range is too difficult to maintain a steady speed due to the rough areas in the lawn.

I got the larger arms and caster tires from Messick's. They are for a Woods 9204RD Turf Batwing. I simple ordered all of the individual parts and assembled them onto the mower. It does make it tight to the rear of the tractor and you have to be careful when you raise it or you will stuff the casters into the rear tires. Below are some comparison pictures.