6420 IVT Trans problems

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6420 IVT Trans problems

Tim I have a 1 year old 6420 with an IVT transmission which has been nothing but problems. Deere replaced the trans, but it still overheating. Is anyone else experiencing similar problems?
Tim Ther is no DTC showing on start up. The problem occurs after about 2 hours of run time. I initially get the yellow exclamation point and the glow plug indicator light flashing with no error messages. Within aboy 15 minutes, the stop warning with a message that the trans is overheating comes on. The trans is infact overheating.
ross First check to make sure the oil in the sight glass is dropping down the sight tube when you start the tractor. Next, is your coolant reservoir full? If it is not then your hydraulics will overheat. The 6020 series tractors have a cooler beind the engine that is cooled with low pressure coolant. Finally take out your air pump in the back of the transmission and check the spring and oring. Thats what I had to do on a 7520 IVT and it was the air pump. The air pump pressurizes the transmission housing to let oil and air pump through the system.
lh did you drain antifreeze from cooling system if so you need to open valve at bottom of radiator to let coolint in other half of radiator
Fez first id pull the codes out of the dash, that would be a good starting point

as stated before id check the radiator for any small leak, we had a unit come to the shop a while ago with the same problem turned out to be a very very small leak in the radiator

Peter Thompson I have a 7920 IVT 9Bought 2nd hand 2 years ago 4000 hours)that had exactly the same problem.
have finally tracked the issues down to a faulty electronic waterpump that ypou have no way of knowing if it is working unles you poke a screwdriver in a tiny windowon it and feel the shaft rotating(unrepairable) that JD was doing a replacement fix on. This involves a totally new type of pump and wiring cost A$2000.
This has cured the overheating but the excessive heating has damaged the PLC sensor in the transmission.

Carl Johnson I have a 7520 thats doing the same thing, so I opened the radiator valve, and turned on the heater and tried to make sure all air was out of the cooling system, next day bailing hay it started flashing overheating agian, the electric coolant pump seams to be working sometimes?
when it started flashing overheating I turned on the heater for a few moments and the overheating light sensor went away? so I'm not sure what to do, I don't want to spend $1500 on the pump if its the airpump? Ross can you point me in the right direction? Thanks

cws Is tractor early sn?possible that thelow pressure part of the cooling system(oil coolerand intercooler)is leaking by inside of radiator.Chick check is to plumb in a piece of clear line in return from oil cooler.Flow should increase at about 180 degrees f.Early models had internal leaks in rad.Also there is a seperate thermostat in the low pressure side.

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