Author	[Modern View]
Al Shaulis Jr 09-08-2012 11:33:29 74.212.2.65 Report to Moderator	My good day was when I was plowing 4 acres with my 720D standard. Tractor running strong and sounded good. Never run out of power and worked it hard. My bad day was the next day when I check the fluid levels in the tractor. Big engine about two quarts low and the pony motor over flowing with oil. I sense that I may have a problem in the big engine. Would that be broken rings? Or is there a vent or breather that could be dirty. Not sure where that would be. I thank you for any help that you can give. Al [Reply]   [No Email]
oldjohndeere 09-09-2012 10:50:44 207.144.125.165 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Al Shaulis Jr, 09-08-2012 11:33:29   When mine did that my day was worse than yours, mine seized from lack of oil. I was using it to pull harrow as all the modern tractors were tied up. Oil was full when I started and two hours later it started to seize. I shut it down before it quit on its on but it was locked up. I was told here it would be an expense repair. When I pulled the crankshaft one rod bearing had started to seize but did no damage. The crank was perfect but the mains were well worn with no noticeable damage from the lack of oil. I found two used outer mains that measured standard for $50.00 and had to buy a new center main for $150.00. I had rebuilt the engine before and it did not have many hours on it but I did not pull the crank then. It runs great now. The right hand seal was bad and all the oil went into the transmission. My pony was full also and the vent is the only thing I can think of to put it there. I have only run it a couple hours since but it is not putting oil in the pony now. [Reply]  [No Email]
johndeere720diesel 09-08-2012 17:52:44 64.135.196.20 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Al Shaulis Jr, 09-08-2012 11:33:29   Mine does that too. It's been getting better with some use. It sat in a barn for 10yrs before i got it after plowing about 4acs plus using it for the past 3 yrs. Just wish the pony issues would get better but oh well [Reply]  [No Email]
Al Shaulis Jr 09-08-2012 16:37:12 74.47.86.169 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Al Shaulis Jr, 09-08-2012 11:33:29   Checked the pony oil, no gasoline smell, had the gas shut off too.. No black measles either. Did get a lot of oil up in the pony motor breather. [Reply]  [No Email]
donmyeil 09-08-2012 14:32:21 74.32.252.164 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Al Shaulis Jr, 09-08-2012 11:33:29   Could be the right side crank seal, Transmission should be overfull as well. Also the big engine vents thru the poney engine , bad rings and too much blow by. [Reply]  [No Email]
F-I-T 09-08-2012 14:54:01 184.6.240.123 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to donmyeil, 09-08-2012 14:32:21   Quoting Removed, click Modern View to see Yes, and I have had one so worn out that the blow by actually filled the pony and ran the breather cup over with oil. Still ran like a champ. He can smell that pony oil and tell quickly if it is a gasoline smell, or looks black like diesel crankcase oil. Sometimes thay don't even smoke too much when they are in tough shape. Black measles on your face is another indicator. [Reply]  [No Email]
Larry Baker 09-08-2012 12:24:28 204.116.154.117 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Al Shaulis Jr, 09-08-2012 11:33:29   The deal with the pony overfull is probably gas that drained into the oil,the deal with the big engine could be several things.Air cleaner clean??could be a ring,hows the level on the back end??? [Reply]  [No Email]
Geoff Mathews 09-09-2012 03:04:44 81.158.132.232 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Larry Baker, 09-08-2012 12:24:28   My 730D pours oil into the back end - could that be a sign of worn rings as well as a worn crank case to transmission seal? [Reply]  [No Email]
F-I-T 09-09-2012 07:27:47 184.6.240.123 Report to Moderator	Re: Jd720 diesel, good day, bad day!!! in reply to Geoff Mathews, 09-09-2012 03:04:44   Quoting Removed, click Modern View to see That's more than likely the RH seal. If you take the engine oil fill cap off, you'll dramatically increase the vent cross sectional area (by a factor of over 36!). I have already wire tied a folded shop rag over that big pipe nipple and used the tractor. If the oil displacement went away or greatly decreased, then I knew the amount of blowby was simply overpowering the pony vent. Remember the hole that the pony vents the diesel through is less than a 1/4" at the closest point. Our 70D was so bad before I rebuilt it, that to use it in the field (it just ran so blasted good) that I ran flex pipe from the oil fill forward and put the end in the slip stream of the intake and let it burn it up. That actually worked pretty well. I could have punched a hole in the valve cover, but did not want to do any permanent damage. [Reply]  [No Email]