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Discussion Starter #1
we use to own a 7720 back when they first came out. i got out of grain farming for several years. a few years ago i started back up. i only have about 500 acres. i have been using an F3 for the last few years. i was able to purcahse a 7720 Titan II this year. can someone that has experince with a 7720 give me a few pointers or advice you think i should know about it? also is there any weak spots that you would recomend ordedring spare parts for and having on the shelf?

thanks
 

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I would keep a close eye on the bolts that hold the final drives on the axles. Also check the fan shroud around the cleaning fan. One year mine cracked all the bolt holes and got into the fan, we farm alot of terraced ground the flexing of the machine over time is hard on stuff. Also the frame on the shaker pans will break if the shaker bushing arent watched closely. Check reverser oil daily and also check oil in two speed cylinder drive gearcase regularly.
There is alot of difference between the early 7720's and the Titan II's. The II's will flat eat, we run a 922 and could go to a 925 pretty easily I would say.
 

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On the Titan 2s, JD sped the shoe up which led to problems later on. My advice would be to get a sprocket off of a pre Titan 2 combine to slow the shoe down. To this day I have not run into anybody that didn't have problems with the shoe being sped up. We had problems on our 8820 until we slowed the shoe down.
 

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The straw chopper, make sure the blades are all there, the bushings on the blades are good, the bearings good, all the bolts on the back hood ok and no vibration. There is somebody that makes a slow down kit, i think it is steven peterson company.
 

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Not a problem. Just remembered that I had a few shots of it. Just not sure that they still make it though. 20 series combines aren't that in demand anymore.
 

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Re: 7720 questions

thanks for the advice.... we get the machine Tuesday. i will check out all the stuff you mentioned. there is a pretty good chance it has the slow down kit on it. it has an extra pulley or to near the chopper. but i will find out for sure when it gets here. i

m a little nervous getting an older used machine a fews weeks before its time to start using it. so hopefully it is in pretty good shape. i looked it over pretty well but as you know I'm sure i missed alot or stuff.

we have a 922 head for it and a 643 corn head with plastic snouts. what kind a of ground speed can i expect in soybeans? I'm use to about 2.5 with a 13 foot head from the old F3 so I'm sure this will be a large improvement. my neighbor has a 9500 that i run alot.will this machine keep up with that?

thanks again for all your info.

Brian
 

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A 7720 tII should keep up with a 9500 very well

if not even maybe pass it up

but havent been around either one that much but they are practically close to being the same machine
 

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Re: 7720 questions

the 7720 arrived yesterday. i found a few things wrong that i missed when i looked it over but nothing to costly. the only thing I'm not very happy with is the steering. it is extremely hard to steer. you almost have to have the engine running wide open in order to steer or it feels like an old car with no power-steering. even wide open it still takes some effort. could this be the steering valve or pump?

also after i cleaned it up i found the main shaft for the bin unloading drive has been welded recently. is this a common way to fix that shaft? i hope it makes it through the season!!!
 

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I've run a 7720 II since 2000. Some things I've done for corn and soybeans. Added a fixed air foil chaffer and really increased the machine's capacity. New rasp bars and a hi capacity concave helped too. I have grain extensions for 200bu capacity and use duals for muck ground. As with any machine, keep the engine compartment clean of grain dust.

An important lesson I learned last year is how to properly grease the intermediate cylinder drive belt (lower sheive). Slow cyl down all the way, take breather plug out of lower sheive, grease zerk in back of shieve until grease comes out of breather hole (do not use the zerk in front), install breather plug, run cyl. speed up and down a couple of times and refill grease in the same previously described manner.

7720 II are good machines. With the airfoil chaffer, I run 4+mph in 180bu corn and 643 head, and I use a 920 head in beans and wheat. Good luck with the machine, you'll like the capacity over your previous setup.
 
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